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This study investigated the effects of a blend of bacillus-fermented soybean meal, functional amino acids, and nucleotides (Functional protein blend-FP Blend) as a replacement for animal protein sources in a weaner pig diet without antibiotic growth promoters on nutrient digestibility, blood profiles, intestinal morphology, diarrhea incidence, and growth performance. A total of 288 crossbred weaned piglets [♂ Duroc x ♀ (Yorkshire × Landrace)] with an average body weight (BW) of 6.89 ± 0.71 kg were randomly allocated to 6 groups based on initial BW and sex (8 replicate pens per treatment; 3 gilts and 3 barrows/pen). The experiment lasted for 5 wk. Dietary treatments included PC [standard diet with 3% fish meal (FM) and 2% plasma protein (PP)], NC (nonanimal protein, AP), T1 (3% FM replaced with 5% FP Blend), T2 (3% FM and 1% PP replaced with 5% FP Blend), T3 (2% PP replaced with 5% FP Blend), and T4 (3% FM and 2% PP replaced with 5% FP Blend). Data were analyzed using Minitab version 17 software. Key results indicated that FP Blend improved the apparent ileal digestibility (AID) coefficient of dry matter, gross energy, lysine, and valine in T4 compared with NC treatment (P < 0.05), whereas AID coefficient of crude protein and other amino acids remained constant (P > 0.05). Compared with NC diet, the weaned pigs fed T4 diet reduced malondialdehyde, serum IL8, TNF-α, and increased IgG (P < 0.05), while showing no effect on serum IL6, IL10, white blood cells, IgA, and endotoxin (P > 0.05). Furthermore, FP blend significantly increased villus height in the duodenum and ileum in T4 compared with NC (P < 0.05). The average daily gain (ADG) was highest in T4 (502.73 g/d), followed by T1 (477.96 g/d) and T2 (475.85 g/d), compared with PC (450.86 g/d) and NC (439.79 g/d). T4's ADG significantly differed from PC and NC (P < 0.001), whereas no significant differences were observed in T1, T2, and T3 (P > 0.05). The feed conversion ratio (FCR) was significantly lower in T4 (1.45) compared with PC (1.57) and NC (1.59) (P < 0.001), with no significant differences among other groups. In conclusion, FP Blend demonstrated efficacy in improving nutrient digestibility, optimizing intestinal morphology, bolstering immune responses, reducing diarrhea incidence, alleviating the adverse effects of weaning stress, and enhancing growth performance of weaned piglets., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The immune response varies between pigs, as not all pigs have the same response to a stressor. This variation may exist between individuals due to body weight (BW) or body composition, which may impact the capacity for coping with an immune challenge (IC). Tryptophan (Trp), threonine (Thr), and methionine (Met) requirements might also play a considerable part in supporting immune system activation while reducing variation between pigs; however, the latter has yet to be reported. This exploratory study investigated the effect of initial BW (light vs. heavy-weight) and supplementation of Trp, Thr, and Met above National Research Council (NRC) requirements on feeding behavior and the coping capacity of growing pigs under an IC. Eighty gilts were categorized into 2 groups according to BW: light-weight (LW, 22.5 kg) and heavy-weight pigs (HW, 28.5 kg). Both BW groups were group-housed for a 28-d trial in a good or poor sanitary condition (SC). Pigs within a poor SC were orally inoculated with 2 × 109 colony units of Salmonella Typhimurium, and fresh manure from a pig farm was spread on the floor. Pigs within good SC were not inoculated, nor was manure spread. Two diets were provided within each SC: control (CN) or supplemented (AA+) with Trp, Thr, and Met at 120% of NRC recommended levels. A principal component analysis was performed in R, and a feeding behavior index was calculated in SAS. Results showed that LW and HW pigs were clustered separately on day 0, where LW pigs had a positive correlation with body lipid percentage (r = 0.83), and HW pigs had a positive correlation with body protein percentage (r = 0.75). After the IC, the cluster configuration changed, with diets influencing LW more than HW pigs within poor SC. On day 14, LW fed AA + diet in poor SC was clustered separately from LW pigs fed CN diet, whereas LW fed AA + and CN diets in good SC were clustered together. For feeding behavior, in both analyzed periods (period 1: days 7 to 14; period 2: days 21 to 28), LW had lower total feed intake and shorter meals than HW pigs (P < 0.10), independent of the SC. Furthermore, LW pigs fed AA + diet had a more regular feed intake pattern than those fed CN diet, while a more irregular pattern was observed for HW pigs fed AA + diet than CN diet at period 2. These findings suggest that supplementing Trp, Thr, and Met above requirements may be a nutritional strategy for LW pigs under IC by improving feed intake regularity and reducing the probability of being susceptible to IC., (© Crown copyright 2024.)

Study objectives were to evaluate the effects of mitoquinol (MitoQ) on production parameters, gastrointestinal tract (GIT; stomach and small and large intestines) weight, and circulating leukocytes during a 24-h acute heat stress (HS) challenge. Crossbred gilts [n = 32; 49.1 ± 2.4 kg body weight (BW)] were blocked by BW and randomly assigned to 1 of 4 environmental-therapeutic treatments: 1) thermoneutral (TN) control (n = 8; TNCON), 2) TN and MitoQ (n = 8; TNMitoQ), 3) HS control (n = 8; HSCON), or 4) HS and MitoQ (n = 8; HSMitoQ). Pigs were moved into individual pens and allowed to acclimate for 6 d. The study consisted of 2 experimental periods (P). During P1 (2 d), all pigs remained in TN conditions (20.6 ± 1.5 °C) and were fed ad libitum. During P2 (24 h), pigs were fed ad libitum and exposed to either TN or constant HS (37.3 ± 1.3 °C). Mitoquinol (40 mg/d) was orally administered twice daily (0700 and 1800 hours) during P1 and P2. As expected, pigs exposed to HS had increased rectal temperature, skin temperature, and respiration rate (+1.5 °C, +8.7 °C, and +86 bpm, respectively; P < 0.01) compared to their TN counterparts. Compared to TN, HS pigs had decreased feed intake (67%; P < 0.01) and significant BW loss (+1.5 vs. -1.9 kg, respectively; P < 0.01). Total GIT weight was decreased in HS relative to TN pigs (P < 0.01), and this was influenced by decreased luminal contents (2.43 vs. 3.26 kg, respectively; P < 0.01) and reduced empty GIT mass (3.21 vs. 3.48 kg, respectively; P = 0.03). Stomach contents remained similar between TN and HS pigs (P > 0.54) but tended to increase in MitoQ relative to CON pigs (0.90 vs. 0.63 kg, respectively; P = 0.08). Stomach content as a percentage of the previous 24 h feed intake was increased in HS compared to the TN controls (93% vs. 31%; P < 0.01). In contrast, small and large intestinal contents were decreased in HS compared to TN pigs (23% and 49%, respectively; P < 0.01). Liver weight decreased in HS relative to TN pigs (1.15 vs. 1.22 kg, respectively; P = 0.02), and was decreased in MitoQ compared to CON pigs (1.13 vs. 1.24 kg; P < 0.01). Circulating lymphocytes tended to be decreased in HS relative to TN pigs (16%; P = 0.07). In summary, acute HS increased all body temperature indices, negatively influenced animal performance, and differentially altered GIT motility as evidenced by decreased gastric emptying and increased intestinal transit. However, MitoQ supplementation did not appear to ameliorate these effects., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Two experiments were conducted to test the hypotheses that particle size of field peas and location where peas are grown do not affect apparent total tract digestibility of nutrients and gross energy, digestible energy (DE), metabolizable energy (ME), and net energy (NE), apparent ileal digestibility (AID) of starch, or standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA). In both experiments, 3 sources of field peas were used. One source was obtained from the United States and 2 sources were obtained from Canada (i.e., Canada 1 and Canada 2). The U.S. field peas were ground to 678, 457, or 265 µm, whereas the 2 sources of Canadian peas were ground to 411 and 415 µm, respectively. Therefore, 5 batches of field peas were used in both experiments. A basal diet contained corn and soybean meal as the only source of energy, starch, and AA, and 5 diets containing corn and soybean meal and 50% of each source of field peas were also formulated. The ratio between corn and soybean meal was 1.92:1 in all diets. In experiment 1, an N-free diet was also used to calculate basal endogenous losses of AA and CP, but in experiment 2, no N-free diet was used. In experiment 1, 7 barrows (initial body weight = 60.6 ± 2.1 kg) that had a T-cannula installed in the distal ileum were allotted to a 7 × 7 Latin square design with 7 diets and 7 periods. In experiment 2, 24 pigs (initial body weight = 30.8 ± 1.0 kg) were housed in 6 calorimeter chambers with 4 pigs per chamber. The 6 chambers were allotted to one of the 6 diets using a 6 × 6 Latin square design with 6 consecutive periods of 15 d. Results of experiment 1 demonstrated that the SID of CP and AA was not influenced by the origin of the peas or by the particle size, but the AID of starch increased (linear, P < 0.001) as particle size was reduced from 678 to 457 or 265 µm. Results of experiment 2 indicated that growing location did not affect concentrations of DE, ME, or NE of field peas, but concentrations of DE, ME, and NE increased (linear, P < 0.05) when particle size was reduced from 678 to 457 or 265 µm. In conclusion, field peas grown in Canada or the United States have the same nutritional value, but starch digestibility and NE increase if the particle size of field peas is reduced., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Gestating sows are often fed a single diet throughout their gestation cycle, leading to situations of nutrients deficiency or excess at the individual level. The purpose of this study was to characterize, over 3 consecutive cycles, the impact of a precision feeding (PF), i.e., dietary supplies adjusted at individual level in terms of quantity (energy intake) and quality (standardized ileal digestible (SID) lysine (Lys) intake), on gestating sows' productive performance, feeding behavior, environmental outputs, and health status compared with sows fed a conventional feeding (CF, i.e., fixed SID Lys intake). At the start of the trial, 2 batches of 20 Landrace × Large White gestating sows were allocated to one of the 2 feeding strategies (PF vs. CF), based on their parity (1, 2, or 3 and more), body weight, and backfat thickness (BT) 3 days after insemination. The PF strategy consisted in mixing with automatic feeders 2 iso-energetic diets (9.8 MJ/kg of net energy with 3.3 and 8.5 g SID Lys/kg, respectively) in variable proportions at individual and daily levels, whereas for the CF strategy these proportions remained constant throughout gestation (73% and 27%, respectively, resulting in an SID Lys concentration of 4.7 g/kg). Sows were followed over 3 consecutive gestations and the sows remained allocated to the same strategy throughout the study. Some sows were culled before the end of the study and were replaced by other sows who therefore performed only 1 or 2 gestations during the study. Thus, 106 gestations and lactations from 51 sows were fully studied and their data analyzed. The PF strategy allowed the sows to reach more closely the expected BT values at farrowing across cycles than the CF strategy (P < 0.001). The PF sows consumed 16% less SID Lys per gestation than the CF sows (P < 0.001), resulting in a 4% improvement in N efficiency (P < 0.001), with no impact on performance at farrowing (P > 0.10). The sows consumed their daily ration in a single visit whatever the feeding strategy (P = 0.41), but CF sows spent more time in the feeder in cycles 2 and 3 (P < 0.001). Thus, compared to the CF strategy implemented by farmers, the individual and daily nutritional supplies implemented with the PF strategy were more efficient in enabling sows to achieve body condition objectives at farrowing over the long term, also with a reduced SID Lys intake and an improved N efficiency without negative impact on farrowing performances., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

A total of 360 pigs (DNA 600 × 241; initially 5.8 kg) were used in a 45-d growth study to evaluate the effects of adding 25(OH)D3 with 3 levels of standardized total tract digestible (STTD) P on nursery pig growth performance, bone and urine characteristics, and serum vitamin D. Pigs were weaned at 19 d of age and randomly allotted to 1 of 6 dietary treatments with 5 pigs per pen and 12 replications per treatment. Dietary treatments were arranged in a 2 × 3 factorial with main effects of 25(OH)D3 (0 or 50 µg/kg equivalent to 2,000 IU/kg of vitamin D3; Hy-D, dsm-firmenich, Plainsboro, NJ) and STTD P (70%, 100%, or 130% of the NRC [NRC 2012. Nutrient requirements of swine. 11th rev. ed. Natl. Acad. Press, Washington, DC) requirement estimate on a dietary percentage basis]. All diets contained 1,653 IU/kg of vitamin D3. On day 45, 1 pig per pen was euthanized to collect the right fibula, metacarpal, and 2nd and 10th ribs. Overall, increasing STTD P increased (quadratic, P ≤ 0.003) ADG, ADFI, and G:F with minimal improvement above 100% of the NRC STTD P requirement estimate. Added 25(OH)D3 had no effect on growth performance. Increasing STTD P decreased urinary Ca concentration (linear, P < 0.001) and increased urinary P concentration (quadratic, P < 0.001). When pigs were fed added 25(OH)D3, serum 25(OH)D3 increased (quadratic, P = 0.005) as STTD P increased but no differences were observed when 25(OH)D3 was not added and STTD P increased (25(OH)D3 × STTD P interaction, P = 0.032). When pigs were fed 25(OH)D3, serum 1,25(OH)2D3 increased (quadratic, P < 0.001) as STTD P decreased but the increase was not significant when no 25(OH)D3 was fed (STTD P × 25(OH)D3 interaction, P = 0.002). Bone ash percentage and weight increased (quadratic, P ≤ 0.065) in all bones as STTD P increased. Added 25(OH)D3 had no effect on bone density or bone ash weight; however, the reduction in bone ash percentage observed with reducing STTD P level tended to be less when 25(OH)D3 was provided (linear interaction, P = 0.098). Increasing STTD P decreased the likelihood of abnormal histologic bone lesions in the 10th rib. In summary, added 25(OH)D3 had limited effect on growth performance; however, an increase in serum concentrations of 25(OH)D3 and 24,25(OH)2D3 was observed. The addition of 25(OH)D3 to P-deficient diets increased percentage bone ash. Increasing STTD P to 100% of NRC [NRC 2012. Nutrient requirements of swine. 11th rev. ed. Natl. Acad. Press, Washington, DC] requirement estimate increased growth and 130% of NRC maximized bone ash., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Accelerometers are useful in analyzing lying behavior in farm animals. The effect of the farrowing system on sow lying behavior has been studied around parturition, but not long-term. In a natural environment, sows increase activity 14 d post parturition, which we expected to be also evident in housed sows when they can move freely. The objective of this study was (1) to validate the methodology to automatically measure sow lying bouts and duration with accelerometers and (2) to apply it to crated and free-farrowing sows 24-h pre-parturition until weaning. We used videos with manual behavior coding as the gold standard for validation and calculated the agreement with an intraclass correlation coefficient (ICC), which was 0.30 (95% CI: -0.10 to 0.64) for the number of lying bouts. When transitional sitting bouts were excluded from the video dataset, the ICC for lying bouts increased to 0.86 (95% CI: 0.40 to 0.95). For lying duration, the ICC was 0.93 (95% CI: 0.26 to 0.98). We evaluated the effects of housing, day relative to parturition, and time of day on lying using the accelerometer data and linear mixed models. In crated sows, the number of lying bouts increased toward parturition, peaking at about five bouts per 6 h, and decreased to almost zero bouts after parturition. Then, it increased again (P = 0.001). In free-farrowing sows, the number of lying bouts gradually decreased from a high level towards parturition and was lowest after parturition. It remained constant, as in the crated sows, until day 15, when the number of bouts increased to eight bouts on day 20 (P = 0.001). Sows in both systems were lying almost all of the time between 18:00 and 00:00 hours and on all days (P = 0.001). The crated sows showed a very similar pattern in the other three-quarters of the day with a reduced lying time before parturition, a peak after parturition, reduced lying time from days 5 to 20, and an increase again towards weaning (P = 0.001). Free-farrowing sows had a similar pattern to the crated sows from 00:00 to 06:00 hours, but without the reduction in lying time from days 5 to 20. They showed an increase in lying time toward parturition, which remained constant with a final decrease toward weaning, especially during the day (P = 0.001). This study proves the accuracy of accelerometer-based sow lying behavior classification and shows that free-farrowing systems benefit lactating sows around parturition but also towards weaning in the nest-leaving phase by facilitating activity., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The objectives of this study were to evaluate the energy partition patterns of growing pigs fed diets with different net energy (NE) levels based on machine learning methods, and to develop prediction models for the NE requirement of growing pigs. Twenty-four Duroc × Landrace × Yorkshire crossbred barrows with an initial body weight of 24.90 ± 0.46 kg were randomly assigned to 3 dietary treatments, including the low NE group (2,325 kcal/kg), the medium NE group (2,475 kcal/kg), and the high NE group (2,625 kcal/kg). The total feces and urine produced from each pig during each period were collected, to calculate the NE intake, NE retained as protein (NEp), and NE retained as lipid (NEl). A total of 240 sets of data on the energy partition patterns of each pig were collected, 75% of the data in the dataset was randomly selected as the training dataset, and the remaining 25% was set as the testing dataset. Prediction models for the NE requirement of growing pigs were developed using algorithms including multiple linear regression (MR), artificial neural networks (ANN), k-nearest neighbor (KNN), and random forest (RF), and the prediction performance of these models was compared on the testing dataset. The results showed pigs in the low NE group showed a lower average daily gain, lower average daily feed intake, lower NE intake, but greater feed conversion ratio compared to pigs in the high NE group in most growth stages. In addition, pigs in the 3 treatment groups did not show a significant difference in NEp in all growth stages, while pigs in the medium and high NE groups showed greater NEl compared to pig in the low NE group in growth stages from 25 to 55 kg (P < 0.05). Among the developed prediction models for NE intake, NEp, and NEl, the ANN models demonstrated the most optimal prediction performance with the smallest root mean square error (RMSE) and the largest R2, while the RF models had the worst prediction performance with the largest RMSE and the smallest R2. In conclusion, diets with varied NE concentrations within a certain range did not affect the NEp of growing pigs, and the models developed with the ANN algorithm could accurately achieve the NE requirement prediction in growing pigs., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

A total of 480 newly weaned pigs (PIC 337 × 1050; Genus, Hendersonville, TN) with an initial body weight (BW) of 6.20 ± 0.61 kg were used in a dose-response study to investigate the impact of increasing standardized ileal digestible (SID) Arg:Lys on nursery pig growth performance. At weaning, pigs were placed into 48 pens with 5 barrows and 5 gilts per pen. Pens were randomly assigned to 1 of 6 dietary treatments. The experimental diets were formulated with increasing SID Arg:Lys, achieved by substituting corn starch, glycine, and l-alanine with l-arginine, resulting in SID Arg:Lys ranging from 45% to 145%. Diets were sublimiting in SID Lys and exceeded all other essential amino acid requirements. The experimental diets were fed across two feeding phases from days 0 to 10 and 10 to 27, with adjustments made to account for the Lys requirement of the pigs. All pens were placed on a common diet for the remaining 14 d of the study to evaluate carryover effects. Pigs and feeders were weighed at the start and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed according to a linear regression model, which included the linear and quadratic effects of SID Arg:Lys and initial BW. Pen was the experimental unit, and results were considered significant at P ≤ 0.05 and a tendency at 0.50 < P ≤ 0.10. From days 0 to 27, Arg:Lys tended to have a quadratic effect on ADFI (P = 0.058), where 97.00 ± 7.631% SID Arg:Lys maximized feed intake. Similarly, Arg:Lys had a quadratic impact on ADG (P = 0.046), where ADG was maximized at a SID Arg:Lys of 95.65 ± 7.165. Correspondingly, Arg:Lys had a quadratic effect on pig BW on day 27 (P = 0.014). These effects were carried through the end of the study, where Arg:Lys quadratically impacted days 0 to 41 ADFI (P = 0.006), ADG (P = 0.077), and day 41 BW (P = 0.028). There was no evidence of an effect of SID Arg:Lys on G:F throughout the study (P ≥ 0.315). In conclusion, SID Arg:Lys quadratically impacted ADFI and ADG in 6- to 13-kg nursery pigs, where ADFI was maximized at a SID Arg:Lys of 97.00% (95% CI [81.6%, 112.4%]), and ADG was maximized at a SID Arg:Lys of 95.65% (95% CI [81.2%, 110.1%]). Together, these data suggest that the SID Arg:Lys requirement of nursery pigs is at least 81%, based on the lower bounds of the 95% CI for maximum ADG and ADFI, and excessive Arg supplementation may negatively affect growth performance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

This study aimed to investigate the nutritional and functional roles of β-mannanase on the intestinal health and growth of newly weaned pigs fed a typical or low-cost formulated feeds (LCF). Twenty-four newly weaned pigs at 6.2 kg ± 0.4 body weight (BW) were allotted to three dietary treatments based on a randomized complete block design with sex and initial BW as blocks. Three dietary treatments are as follows: Control, typical nursery feeds including animal protein supplements and enzyme-treated soybean meal; LCF with increased amounts of soybean meal, decreased amounts of animal protein supplements, and no enzyme-treated soybean meal; LCF+, low-cost formulated feed with β-mannanase at 100 g/t, providing 800 thermostable β-mannanase unit (TMU) per kg of feed. Pigs were fed based on a three-phase feeding program for a total of 37 d. On day 37 of feeding, all pigs were euthanized and the gastrointestinal tract was removed for sample collection to analyze intestinal health parameters, mucosa-associated microbiota, and gene expression of tight junction proteins. Pigs fed LCF increased (P < 0.05) the relative abundance of Proteobacteria and Helicobacter in the jejunal mucosa, tended to decrease (P = 0.097; P = 0.098) the concentration of malondialdehyde (MDA) and the expression of zona occluden 1 (ZO-1) gene in the jejunum, tended to decrease average daily gain (ADG; P = 0.084) and final BW (P = 0.090), and decreased (P < 0.05) average daily feed intake. Pigs fed LCF + tended to decrease (P = 0.088) digesta viscosity, decreased (P < 0.05) the relative abundance of Helicobacter, and increased (P < 0.05) Lactobacillus in the jejunal mucosa compared to LCF. Additionally, LCF + tended to increase final BW (P = 0.059) and ADG (P = 0.054), increased (P < 0.05) gain to feed ratio (G:F), and reduced (P < 0.05) fecal score compared to LCF. LCF with decreased amounts of animal protein supplements and increased amounts of soybean meal had negative effects on the composition of the mucosa-associated microbiota, intestinal integrity, and growth performance of nursery pigs. Beta-mannanase supplementation to LCF decreased digesta viscosity, increased the relative abundance of potentially health-benefitting microbiota such as Lactobacillus, and improved growth and fecal score, thus reflecting its efficacy in low-cost formulated feeds with increased amounts of soybean meal., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

This study compared milk replacer either remaining unsupplemented (CON) or supplemented with 0.5 g L-carnitine plus 16.7 g L-arginine/kg (CarArg) and fed to 48 low-birth weight (L-BtW) artificially reared piglets (24 per group) from days 7 to 28 of age. Eight farrowing series were needed to complete the study. On day 28, the lightest piglets were slaughtered, and the heaviest pigs were weaned. The heaviest pigs were weaned on day 28 and offered free access to a starter (weaning to 25 kg body weight [BW]), grower (25 to 60 kg BW), and finisher diet (60 to 96 kg BW on day 170 of age). After euthanization on days 28 and 170, blood was sampled for assessment of serum metabolite and hormone concentrations, and the semitendinosus muscle (STM) was weighed, and later subjected to enzyme activity analysis and assessment of myofiber characteristics. In the 170-d-old pigs carcass and meat quality traits were assessed. Growth data were analyzed accordingtoatwo-way analysis of variance (ANOVA), with dietary treatment and farrowing series as fixed effects, while remaining data were analyzed with dietary treatment, sex, their interaction, and farrowing series as main factors. Dietary treatments affected (P ≤ 0.049) muscle enzyme activity at both day 28, with greater citrate synthase (CS) and LDH activities and lower HAD:CS ratio in STM light portion, and lower LDH:CS ratio in STM dark portion, and 170 of age with lower HAD:CS ratio. In the starter period, CarArg pigs had greater average daily gain (P = 0.021) and average daily feed intake (P = 0.010). At slaughter, these pigs had lower (P = 0.013) glucose and greater (P = 0.022) urea serum concentrations. However, supplementing the milk replacer with carnitine and arginine had no long-term effects on growth performance, carcass composition, and meat quality of L-BtW pigs. In addition, muscle morphology and myofiber-related properties remained unaffected by the supplementation., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The objective of the present experiment was to determine the minimum adaptation period for total tract digestibility experiments in gestating and lactating sows using the indigestible index method. Five gestating and 5 lactating sows at parities 3 to 5 were used. An indigestible index of 0.5% chromic oxide was supplemented to a diet based on corn and soybean meal. The daily feed allowance for gestating sows was 2 kg and 2 equal meals were provided to the sows. Lactating sows were fed 6 kg of feed per day in 3 equal meals. After feeding a diet without supplemental chromic oxide for 5 d, index-supplemented diets were provided to the gestating and lactating sows. Feces were collected at 24-h intervals for 9 and 7 d from gestating and lactating sows, respectively. Fecal Cr concentrations increased linearly (P < 0.001) and quadratically (P < 0.001) with collection time in both gestating and lactating sows. Minimum adaptation periods were estimated by one-slope broken-line model. The break point of Cr concentrations in feces was day 7.2 (SE = 0.3) in the gestating sows and day 4.2 (SE = 0.2) in the lactating sows, respectively. Apparent total tract digestibility of dry matter, organic matter, and energy on day 4 was less (P < 0.001) than that on days 8 to 9 in gestating sows fed the experimental diet with a 2-kg feed allowance. In lactating sows fed the experimental diets with a 6-kg feed allowance, the apparent total tract digestibility of dry matter, organic matter, and energy on day 3 was less (P < 0.05) than that on days 5 to 7. In conclusion, at least 8 d of adaptation period are required for gestating sows to determine total tract digestibility using Cr as the indigestible index method whereas 5 d of adaptation period are required for lactating sows. An insufficient adaptation period results in lower digestibility values., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The negative effects of heat stress on swine reproduction have been well documented and the recent global warming trend caused by climate change is leading to more days with high temperatures every year. This has caused a reduction in litter trait performance of Landrace sows in Taiwan, a country extending across tropical and subtropical oceanic zones. Therefore, this study developed a modified model to determine which stages of pregnancy, before, early, middle, and late, had the largest impacts of heat stress on litter traits. A reaction norm model (RNM) was used to identify sows with high resilience to heat stress for litter traits followed by analysis of the modified model. Data from Landrace sows were collected from 2 farms in Taiwan between 2008 and 2021. A total of 11,059 records were collected for total number born (TNB), number born alive (NBA), and stillborn rate (STBR). The results showed that the heritabilities of TNB, NBA, and STBR were 0.170, 0.115, and 0.077, respectively. These results were similar between the conventional model and the modified model. In the modified model, the before and early stages of sow pregnancy were the significant periods for TNB and NBA (P < 0.05), while the early and middle stages were significant for STBR (P < 0.05). According to the RNM results, the heritability estimates for TNB, NBA, and STBR were 0.23 to 0.11, 0.18 to 0.08, and 0.10 to 0.04, respectively, showing a decrease from low temperature-humidity index (THI) to high THI. The minimum genetic correlations between the highest and the lowest THI for TNB, NBA, and STBR were 0.85, 0.64, and 0.80, respectively. The results of the RNM for breeding value showed re-ranking across THI values. In conclusion, similar results were obtained for heritability when the model was modified for heat stress estimation. Yet re-ranking of breeding values across THI could help farmers to select not only for improved litter trait performance but also for heat stress resilience of Landrace sows in Taiwan., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This study evaluated the ability of 2 penetrating captive bolt (PCB) types (PISTOL, INLINE) to reach and disrupt the thalamus when applied in 2 placements (FRONTAL, BEHIND EAR) to chilled cadaver heads (N = 60) from sows >200 kg. Heads were randomly distributed across 6 treatments (n = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR-PISTOL, and BEHIND EAR-NO SHOT. The FRONTAL shot was placed 3.5 cm superior to the optic orbits at the midline; the BEHIND EAR shot was placed directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For INLINE treatments, a Jarvis PAS-Type C 0.25R Super Heavy Duty PCB with a Long Bolt and 6.0 GR power loads was used. For PISTOL treatments, a Jarvis PAS-Type P 0.25R Pistol PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 GR power loads was used. Heads were split along the bolt with a band saw. Tissue depth measurements are reported as Mean ± SE followed by 97.5% one-sided upper reference limit (URL). Total tissue thickness was less (P < 0.0001) at the FRONTAL (56.31 ± 1.76 mm; URL: 73.17 mm) than the BEHIND EAR placement (95.52 ± 3.30 mm; URL: 126.53 mm). Thalamic depth was less (P < 0.0001) at the FRONTAL (78.31 ± 1.32 mm; URL: 88.19 mm) than the BEHIND EAR placement (111.86 ± 3.22 mm; URL: 135.99 mm). The effective angle was greater (P < 0.0001) at the FRONTAL (4.72 ± 0.20°) than the BEHIND EAR placement (3.22 ± 0.17°). Potential for bolt-brain contact was not different (P = 1.0000) between FRONTAL-INLINE (10/10, 100% ± 0.01%), FRONTAL-PISTOL (10/10, 100% ± 0.01%), BEHIND EAR-INLINE (9/10, 90% ± 9.49%), and BEHIND EAR-PISTOL (10/10, 100% ± 0.01%); brain damage (P = 0.5577) between FRONTAL-INLINE (9/9, 100% ± 0.02%), FRONTAL-PISTOL (10/10, 100% ± 0.02%), BEHIND EAR-INLINE (4/10, 40% ± 15.49%), and BEHIND EAR-PISTOL (1/10, 10% ± 9.49%); potential for bolt-thalamus contact (P = 0.0683) for FRONTAL-INLINE (2/10, 20% ± 12.65%), FRONTAL-PISTOL (8/10, 80% ± 12.65%), BEHIND EAR-INLINE (7/9, 77.78% ± 13.86%), and BEHIND EAR-PISTOL (9/9, 100% ± 0.02%); or thalamic damage (P = 0.8041) for FRONTAL-INLINE (1/10, 10% ± 9.49%), FRONTAL-PISTOL (1/10, 10% ± 9.49%), BEHIND EAR-INLINE (2/8, 25% ± 15.31%), and BEHIND EAR-PISTOL (0/9, 0% ± 0.00%). The FRONTAL placement with an INLINE PCB may present the least risk of failure for the PCB euthanasia of mature sows >200 kg body weight due to less total tissue thickness and thalamic depth, greater effective angle, and prevalent brain damage., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Fifty-two multiparous sows (average parity 3.1 ± 0.9 and initial BW 245.6 ± 32.5 kg) were used to evaluate the effects of dietary standardized ileal digestible (SID) Lys-to-net energy (NE) ratios on nitrogen (N) utilization throughout a 24-d lactation period. Sows were randomly assigned to one of five isoenergetic feeding programs that provided equally spaced and increasing SID Lys-to-NE ratios between 2.79 and 5.50 g SID Lys/Mcal NE. The feeding programs were generated by blending the two extreme diets in varying proportions and were provided to sows immediately after farrowing (day 1) and until weaning at day 24 ± 1. Nitrogen balances were conducted between days 4 and 7, 12 and 15, and 20 and 23 ± 1 of lactation to represent weeks 1, 2, and 3, respectively, using total urine collection and fecal grab sampling. Contrast statements were used to determine the linear and quadratic effects of increasing Lys-to-NE ratios. Linear and quadratic broken-line and polynomial quadratic (QPM) models were used to determine the optimum dietary Lys-to-NE ratios for N retention in milk. The Bayesian information criterion was used to assess the best fit. Feeding program did not influence sow average daily feed intake (5.8 ± 0.1 kg), BW change (-8.2 ± 3.1 kg), or change in back fat thickness (-2.6 ± 0.7 mm) over the 24-d lactation period, but piglet average daily gain increased with dietary SID Lys-to-NE ratio (linear; P < 0.05). Sow N intake increased with increasing dietary Lys-to-NE ratio in weeks 2 and 3 (linear; P < 0.001). Whole-body N retention (N intake - N output in urine and feces) increased with increasing dietary Lys-to-NE ratio in all weeks (linear; P < 0.05). The N retention in milk tended to increase then decrease with increasing dietary Lys-to-NE ratio in weeks 1 and 2 (quadratic; P = 0.051 and P = 0.081) and the QPM showed optimal milk N retention at 4.28, 4.42, and 4.67 g Lys/Mcal NE for weeks 1, 2, and 3, respectively. Maternal N retention (N intake - N output in urine, feces, and milk) decreased and then increased in week 1 (quadratic; P < 0.01) and increased in weeks 2 and 3 (linear; P < 0.01) with increasing dietary Lys-to-NE ratio. Therefore, the SID Lys-to-NE ratio necessary to optimize milk N output is dynamic throughout lactation. A two-diet feeding program could be created to match optimal weekly or daily SID Lys-to-NE ratios, which could lead to improved piglet ADG and body weights at weaning., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

A total of 882 pigs (PIC TR4 × [Fast LW × PIC L02]; initially 33.2 ± 0.31 kg) were used in a 112-d study to evaluate the effects of different bones and analytical methods on the assessment of bone mineralization response to changes in dietary P, phytase, and vitamin D in growing pigs. Pens of pigs (20 pigs per pen) were randomized to one of five dietary treatments with nine pens per treatment. Dietary treatments were designed to create differences in bone mineralization and included: 1) P at 80% of NRC (2012) standardized total tract digestible (STTD) P requirement, 2) NRC STTD P with no phytase, 3) NRC STTD P with phytase providing an assumed release of 0.14% STTD P from 2,000 FYT/kg, 4) high STTD P (128% of the NRC P) using monocalcium phosphate and phytase, and 5) diet 4 with additional vitamin D3 from 25(OH)D3. On day 112, one pig per pen was euthanized for bone, blood, and urine analysis. Additionally, 11 pigs identified as having poor body condition which indicated a history of low feed intake (unhealthy) were sampled. There were no differences between treatments for final body weight, average daily gain, average daily feed intake, gain to feed, or bone ash measurements (treatment × bone interaction) regardless of bone ash method. The response to treatment for bone density and bone mineral content was dependent upon the bone sampled (density interaction, P = 0.053; mineral interaction, P = 0.078). For 10th rib bone density, pigs fed high levels of P had increased (P < 0.05) bone density compared with pigs fed NRC levels with phytase, with pigs fed deficient P, NRC levels of P with no phytase, and high STTD P with extra 25(OH)D3 intermediate, with no differences for metacarpals, fibulas, or 2nd ribs. Pigs fed extra vitamin D from 25(OH)D3 had increased (P < 0.05) 10th rib bone mineral content compared with pigs fed deficient P and NRC levels of P with phytase, with pigs fed industry P and vitamin D, and NRC P with monocalcium intermediate. Healthy pigs had greater (P < 0.05) serum Ca, P, vitamin D concentrations, and defatted bone ash than those unhealthy, with no difference between the two health statuses for non-defatted bone ash. In summary, differences between bone ash procedures were more apparent than differences between diets. Differences in bone density and mineral content in response to dietary P and vitamin D were most apparent with 10th ribs., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The integrity of the intestinal barrier is crucial for regulating the passage of pathogens and toxins, while facilitating nutrient absorption. The everted gut sac technique, an ex-vivo technique, can be used to study interventions on barrier function. This cost-effective approach utilizes relatively large gut segments to study specific intestinal regions. Typically, intact (non-stripped) intestinal segments are used, but their use may underestimate permeability due to the medial positioning of blood vessels relative to the seromuscular layer and serosa. However, removing these layers risks physical damage, resulting in an overestimation of intestinal permeability. Therefore, we investigated the impact of stripping jejunal segments on permeability to fluorescein isothiocyanate-dextran (FITC, 4 kDa) and tetramethylrhodamine isothiocyanate-dextran (TRITC, 40 kDa), and on the absorption of glucose, lysine, and methionine in jejunal segments from 80 piglets at 8 d postweaning. Piglets were subjected to either high or low sanitary housing conditions and diets provoking intestinal protein fermentation or not, expected to influence intestinal permeability. Stripping of the seromuscular layer and serosa increased the passage of 4 kDa FITC-dextran (stripped vs. non-stripped; 1.1 vs. 0.9 pmol/cm2/min, P < 0.001), glucose (40.0 vs. 19.1 pmol/cm2/min, P < 0.001), lysine (2.5 vs. 2.0 nmol/cm2/min, P < 0.001), and methionine (4.1 vs. 2.7 pmol/cm2/min, P < 0.001). As permeability increased, the differences in methionine passage between stripped and non-stripped intestinal segments also increased (slope = 1.30, P = 0.009). The coefficients of variation were comparable between stripped and non-stripped intestines (over all treatments, stripped vs. non-stripped 38% vs. 40%). Stripping, by isolating mucosal processes without introducing additional variation, is thus recommended for studies on intestinal permeability or absorption., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Nitrogen and phosphorus excretion are major sources of environmental contamination in growing-finishing pig operations. Nutrient excretion can be reduced by feeding pigs daily-tailored diets to their estimated nutrient requirements using individual precision feeding (IPF) techniques. This study modeled and evaluated the environmental impact of moving from conventional group 3-phase feeding (CGF) to IPF systems in Quebec, Canada, using life-cycle assessment with SimaPro software. The cradle-to-farm model included inputs and outputs of each subphase: raw materials/feedstuffs production, feed mill processing, transport, animal rearing, and manure management. The model was identical for both treatments in all aspects except for the production of feeds and barn and manure emissions in the growing-finishing phases. All feed ingredients originated from Quebec, simulating agricultural practices using real management data from an average farm in Quebec. Based on observed pig growth data, the CGF and IPF systems were compared in the growing-finishing phase. IPF diets were modeled as the blend of 2 feeds (i.e., A and B), while CGF diets were stablished according to the industry. The evaluated impact categories were global warming potential (GWP), eutrophication potential (EP), and acidification potential (AP). The functional unit was 1 t of feed at the feed mill gate and 1 t of finished pig live weight at the farm gate. A Monte Carlo analysis determined the uncertainty of the growth performance results. Feeding programs were compared using analysis of variance. Corn was associated with elevated GWP and AP impacts, leading to higher impacts for diets with higher corn content. Feed B, which contained 83% corn, resulted in impacts of 645 kg of CO2-eq., 8.53 kg SO2-eq., and 4.89 kg PO4-eq. Diets with higher EP impact had a higher percentage of soybean meal. Feed A contained 25% of this ingredient and had an impact of 608 kg CO2-eq., 6.98 kg SO2-eq., and 5.57 kg PO4-eq. CGF diets had environmental impacts between those of feeds A and B. Compared to CGF, applying IPF programs during the growing-finishing phase decreased GWP by 7.6%, AP by 16.2% and EP by 13.0%. IPF significantly reduced the environmental impact in all categories through the more efficient use of nutritional resources by pigs. IPF could help to improve the sustainability of growing-finishing pig operations in Quebec and likely other regions using corn and soybean-based diets., (© Crown copyright 2024.)

The purpose of this investigation was to establish the role biological sex plays in circulating factors following heat stress (HS). Barrows and gilts (36.8 ± 3.7 kg body weight) were kept in either thermoneutral (TN; 20.8 ± 1.6 °C; 62.0% ± 4.7% relative humidity; n = 8/sex) conditions or exposed to HS (39.4 ± 0.6 °C; 33.7% ± 6.3% relative humidity) for either 1 (HS1; n = 8/sex) or 7 (HS7; n = 8/sex) d. Circulating glucose decreased as a main effect of the environment (P = 0.03). Circulating non-esterified fatty acid (NEFA) had an environment × sex interaction (P < 0.01) as HS1 barrows had increased NEFA compared to HS1 gilts (P = 0.01) and NEFA from HS7 gilts increased compared to HS1 gilts (P = 0.02) and HS7 barrows (P = 0.04). Cortisol, insulin, glucagon, T3, and T4 were reduced as a main effect of environment (P ≤ 0.01). Creatinine was increased in HS1 and HS7 animals compared to TN (P ≤ 0.01), indicative of decreased glomerular filtration rate. White blood cell populations exhibited differential patterns based on sex and time. Neutrophils and lymphocytes had an environment × sex interaction (P ≤ 0.05) as circulating neutrophils were increased in HS1 barrows compared to TN and HS7 barrows, and HS1 gilts (P ≤ 0.01) and HS7 barrows had less neutrophils compared to TN barrows (P = 0.01), whereas they remained similar in gilts. In contrast, barrow lymphocyte numbers were similar between groups, but in HS7 gilts they were decreased compared to TN and HS1 gilts (P ≤ 0.04). In total, these data demonstrate that HS alters a host of circulating factors and that biological sex mediates, at least in part, the physiological response to HS., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Study objectives were to characterize the effects of citrulline (CIT) on physiological and intestinal morphology metrics during heat stress (HS) and feed restriction. Forty crossbred gilts (30 ± 2 kg body weight [BW]) were assigned to one of five treatments: (1) thermoneutral (TN) fed ad libitum (AL) with control (CON) supplement (TNAL; n = 8), (2) TN pair-fed (PF) with CON (PF-CON; n = 8), (3) TN PF with CIT (PF-CIT; n = 8), (4) HS AL with CON (HS-CON; n = 8), and (5) HS AL with CIT (HS-CIT; n = 8). During the period (P) 1 (7 d), pigs were in TN conditions (23.6 °C) and fed AL their respective supplemental treatments. During P2 (2.5 d), HS-CON and HS-CIT pigs were fed AL and exposed to cyclical HS (33.6 to 38.3 °C), while TNAL, PF-CON, and PF-CIT remained in TN and were fed either AL or PF to their HS counterparts. Citrulline (0.13 g/kg BW) was orally administered twice daily during P1 and P2. HS increased rectal temperature (Tr), skin temperature (Ts), and respiration rate (RR) relative to TN pigs (0.8 °C, 4.7 °C, and 47 breaths/min, respectively; P < 0.01). However, HS-CIT had decreased RR (7 breaths/min, P = 0.04) and a tendency for decreased Tr (0.1 °C, P = 0.07) relative to HS-CON pigs. During P2, HS pigs had decreased feed intake (22%; P < 0.01) and a tendency for decreased average daily gain (P = 0.08) relative to TNAL pigs, and by experimental design, PF pigs followed this same pattern. Circulating lipopolysaccharide-binding protein tended to be decreased (29%; P = 0.08) in PF relative to TNAL pigs and was increased (41%; P = 0.03) in HS compared to PF pigs. Jejunum villus height was decreased in PF relative to TNAL pigs (15%; P = 0.03); however, CIT supplementation improved this metric during feed restriction (16%; P = 0.10). Jejunum mucosal surface area decreased in PF (16%; P = 0.02) and tended to decrease in HS (11%; P = 0.10) compared to TNAL pigs. Ileum villus height and mucosal surface area decreased in HS compared to TNAL pigs (10 and 14%, respectively; P ≤ 0.04), but both parameters were rescued by CIT supplementation (P ≤ 0.08). Intestinal myeloperoxidase and goblet cell area remained similar among treatments and intestinal segments (P > 0.24). In summary, CIT supplementation slightly improved RR and Tr during HS. Feed restriction and HS differentially affected jejunum and ileum morphology and while CIT ameliorated some of these effects, the benefit appeared dependent on intestinal section and stressor type., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The aim of the study was to investigate whether increased inclusion of sugar beet pulp (SBP) alters retention of fat, protein, and energy when backfat (BF) is restored in early- and mid-gestation. In total, 46 sows were fed one of four dietary treatments with increasing inclusion of SBP providing dietary fiber (DF) levels of 119, 152, 185, and 217 g/kg; sows were assigned to one of three feeding strategies (FS; high, medium, and low) depending on BF thickness at mating and again at day 30 for the following month. On days 0, 30, 60, and 108, body weight (BW) and BF thickness were measured and body pools of protein and fat were estimated using the deuterium oxide technique. On days 30 and 60, urine, feces, and blood samples were collected to quantify metabolites, energy, and nitrogen (N) balances. On days 15 and 45, heart rate was recorded to estimate heat energy. At farrowing, total born and weight of the litter were recorded. In early gestation, BW gain (P < 0.01) and body protein retention increased (P < 0.05) with increasing fiber inclusion, while body fat retention increased numerically by 59%. The increase in BF was greatest for sows fed the high FS, intermediate when fed the medium strategy, and negligible for sows fed the lowest FS (P < 0.001). Nitrogen intake, N loss in feces, and N balance increased linearly, whereas N loss in urine tended to decrease with increasing inclusion of fibers in early gestation. Concomitantly, fecal energy output and energy lost as methane increased linearly (P < 0.001), while energy output in urine declined linearly. Total metabolizable energy (ME) intake therefore increased from 36.5 MJ ME/d in the low fiber group to 38.5 MJ ME/d in the high fiber group (P < 0.01). Changing the ME towards more ketogenic energy was expected to favor fat retention rather than protein retention. However, due to increased intake of ME and increased N efficiency with increasing fiber inclusion, the sows gained more weight and protein with increasing fiber inclusion. In conclusion, increased feed intake improved both fat and protein retention, whereas increased DF intake increased protein retention., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The objective of this research was to determine the effects of mid-gestational maternal inflammation on performance, carcass characteristics, and meat quality of offspring. Pregnant gilts were administered either lipopolysaccharide (LPS; n = 7) or saline (CON, n = 7) from days 70 to 84 of gestation. Gilts assigned to the LPS treatment were administered an intravenous injection of reconstituted LPS every other day with a beginning dose of 10 μg LPS/kg body weight and subsequent doses increasing by 12%, while CON gilts received intravenous injections of comparable volumes of saline. Gilts farrowed naturally, and at day 66 of age, a total of 59 pigs, both barrows and gilts began a 3-phase feeding regimen designed to meet or exceed nutrient requirements for growing-finishing pigs. Pigs were weighed on days 0, 35, 70, and 105 of the finishing trial to determine average daily gain, average daily feed intake, and gain-to-feed ratio (G:F). On day 106, pigs were slaughtered under the supervision of the U.S. Department of Agriculture Food Safety Inspection Service. Ending live weight, hot carcass weight, and dressing percentage were determined. The left side of carcasses was weighed and fabricated to determine carcass cutting yields. The semitendinosus was collected for histological samples. Fresh belly characteristics and loin quality were measured. Two chops were collected for Warner-Bratzler shear force and proximate analysis. No differences (P ≥ 0.13) between LPS and CON pigs were observed for growth performance in phases 1, 2, 3, or overall (days 0 to 105) performance with the exception of overall G:F reduced in CON pigs compared with LPS pigs (P = 0.03). There was a tendency for carcass yield to be reduced (P = 0.06; 0.82% units) in LPS pigs compared with CON pigs. Additionally, longissimus muscle area tended to be reduced (P = 0.10) 2.27 cm2 in LPS compared with CON pigs. Loin chop quality traits including instrumental color, subjective color, marbling, firmness, pH, and drip loss were not different (P ≥ 0.09) between LPS and CON pigs. Fresh belly characteristics were not different (P ≥ 0.22) between LPS and CON pigs. There were no differences in primal and subprimal weights, except that LPS pigs tended to have a reduction (P ≥ 0.07) in tenderloin and Canadian back weights compared with CON pigs. Furthermore, LPS pigs had no differences (P ≥ 0.25) in muscle fiber composition or size; however, LPS pigs tended (P = 0.10) to have a 13% reduction in estimated muscle fibers number compared with CON pigs. In summary, mid-gestational inflammation did not result in reduced meat quality, growth performance, or carcass yields of offspring., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Variation in feed intake results in nearly 20% of sows consuming less than the recommended lysine (Lys) intake for lactating sows. The Lys requirement for lactating sows is based on litter size and piglet average daily gain which influences milk production. Litter size continues to increase every year causing the need for routine reevaluation of nutrient requirements. If dietary inclusion levels are not continuously adjusted this can lead to inadequate daily Lys and energy intake and may negatively impact sow body condition and litter performance. The objective was to characterize the average daily feed intake (ADFI) of sows and define feed intake patterns and their effects on sow body weight, farrowing performance, litter performance, and subsequent farrowing performance. ADFI during lactation was recorded for 4,248 sows from 7 independent research studies. Data collection occurred from November 2021 through November 2023 at a commercial breed-to-wean facility in western Illinois. Each sow was categorized as: consistently low intake (< 5.5 kg/d) throughout the lactation (LLL); low intakes (< 5 kg/d) in the first week, then gradually increased throughout the rest of the lactation period (LHH); gradual increase in intake throughout lactation with no drop and a peak intake after day 10 of lactation (gradual); rapid increase in intake with no drop and the peak intake met before day 10 (rapid); a major drop in feed intake (> 1.6 kg decrease for ≥ 2 d) any time during lactation (MAJOR); minor drop (≤ 1.6 kg for ≥ 2 d; MINOR). Sows were also separated into low (quartile 1; ≤ 25%), average (quartile 2 through 3), or high feed intake (quartile 4; ≥ 75%) by parity (P1, P2, P3+). Sows in the LLL category were younger in parity, had the greatest preweaned mortality, weaned the lightest average pigs, and experienced the greatest loss in body weight percentage compared with sows in all other feed intake categories. Furthermore, sows in the LLL and LHH categories had one fewer subsequent pig born compared with sows in the other four categories. These data support historical findings that feed intake patterns directly contribute to current litter farrowing performance. Lactation intake patterns also influence subsequent farrowing performance. Identifying under-consuming sows that are likely Lys and energy deficient allows producers opportunities to promote consistent, adequate daily intakes to these groups and mitigate negative impacts on sow and litter performance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

In this study, pigs from 3 supply chains were slaughtered in an Australian summer and winter (n = 20 for each supply chain). The pigs were from 2 sexes (female and castrated male) and 2 carcass weight groups (high: 95.0 to 100.0 kg and low: 75.0 to 80.0 kg). From each carcass, the Biceps femoris (BF), Longissimus thoracis et lumborum (LTL), and Triceps brachii (TB) were excised at 24 h postmortem, vacuum packed, frozen at 24-48 h and transported to the lab. Cooking loss, Warner-Bratzler shear force (WBSF) and texture profile analysis (adhesiveness, chewiness, cohesiveness, hardness, resilience, and springiness) were measured in LTL and BF. pH, collagen content, and solubility and intramuscular fat (IMF) content were determined for all muscles. Results showed that BF was tougher than LTL, and winter samples were tougher than summer ones (P < 0.05). The TB had higher pH, collagen, and IMF content than BF and LTL (P < 0.05). Collagen solubility was higher in castrated male and winter samples. pH, collagen solubility, and IMF content were significantly (P < 0.05) related to chewiness and hardness in pork BF and LTL. pH and IMF were also related to cooking loss, while collagen solubility and IMF were related to WBSF (P < 0.05). The relationships of pH and IMF with pork texture were predominantly driven by the LTL, while the relationships between collagen solubility and texture were predominantly driven by the BF. Collagen solubility and IMF of pork BF and TB were related to those of LTL, but the correlations were not strong enough for prediction. Pork texture and chemical components were affected by muscle, seasons, sex and carcass weight. pH, collagen solubility, and IMF-affected pork texture., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Fifty gilts (initial body weight [BW] 190.7 ± 4.2 kg) were recruited on day 85 of gestation and were used until day 19 of lactation to assess the dose-response of inactivated yeast via hydrolyzation (HY) inclusion on offspring growth and immunoglobulin (Ig) transfer prior to weaning. Gilts were assigned to one of the 5 experimental diets: a control with no HY (HY0) or inclusion of 0.25% (HY0.25), 0.5% (HY0.5), 1.0% (HY1.0), or 1.2% (HY1.2) HY. Gilts were weighed on days 85 and 110 of gestation and days 1 and 19 (weaning) after farrowing. Offspring were weighed on days 1 and 19 of age. On lactation day 1 (approximately 24 h after farrowing), colostrum, gilt plasma, and plasma from 2 median BW piglets were collected and on day 19, plasma from each gilt and 2 median BW piglets per litter were collected for determination of Ig concentrations. Contrast statements were used to assess the linear, quadratic, cubic, and quartic effects of HY inclusion. The inclusion of HY had minimal effects on gilt BW or litter characteristics at birth (total number born and born alive, piglet birth weight). Lactation average daily feed intake of the gilts tended to increase then decrease with increasing HY inclusion (quadratic; P = 0.085). Piglet preweaning average daily gain (linear, quadratic, and quartic; P < 0.05) and BW at weaning (quadratic and quartic; P < 0.05) increased then decreased with increasing HY inclusion. On lactation day 1, colostrum and gilt plasma Ig concentrations were not affected by dietary treatment (P > 0.10) but piglet IgA and IgM decreased then increased with HY inclusion level (cubic; P < 0.05). On lactation day 19, piglet plasma IgG tended to increase with HY inclusion (linear; P = 0.099). In summary, increasing HY inclusion in late gestating and lactating gilt diets improved immune transfer in the first 24 h after birth and piglet preweaning growth rates and BW at weaning. Therefore, maternal feeding of HY could be used as a strategy to improve offspring immunocompetence and BW at weaning, with possible carryover benefits for the postweaning phase., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

This experiment aimed to investigate the effects of dietary iron supplementation from different sources on the reproductive performance of sows and the growth performance of piglets. A total of 87 sows with similar farrowing time were blocked by body weight at day 85 of gestation, and assigned to one of three dietary treatments (n = 29 per treatment): basal diet, basal diet supplemented with 0.2% ferrous sulfate (FeSO4), and basal diet supplemented with 0.2% iron sucrose, respectively, with 30% iron in both FeSO4 and iron sucrose. Compared with the control (CON) group, iron sucrose supplementation reduced the rate of stillbirth and invalid of neonatal piglets (P < 0.05), and the number of mummified fetuses was 0. Moreover, it also improved the coat color of newborn piglets (P < 0.05). At the same time, the iron sucrose could also achieve 100% estrus rate of sows. Compared with the CON group, FeSO4 and iron sucrose supplementation increased the serum iron content of weaned piglets (P < 0.05). In addition, iron sucrose increased serum transferrin level of weaned piglets (P < 0.05) and the survival rate of piglets (P < 0.05). In general, both iron sucrose and FeSO4 could affect the blood iron status of weaned piglets, while iron sucrose also had a positive effect on the healthy development of newborn and weaned piglets, and was more effective than FeSO4 in improving the performance of sows and piglets., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This study evaluated the effect of dietary calcium (Ca) levels and deoxynivalenol (DON) contamination on Ca and phosphorus (P) utilization and bone mineralization in piglets. During an initial 13-d depletion phase, 64 piglets (15.7 ± 0.7 kg) received a control (DON-) or DON-contaminated treatment (DON+, 2.7 mg DON/kg) with either a low Ca (Ca-, 0.39%) or normal Ca level (Ca+, 0.65%) with a constant digestible P level (0.40%). A second group of 16 piglets received DON- or DON+ treatments for 9 d for gene expression analysis. During the subsequent 14-d repletion phase, all piglets were fed a Ca+ DON- diet containing 0.65% Ca and 0.35% digestible P without DON. After 5 d of the depletion phase, the absorption of P (DON × Ca; P < 0.05) and Ca was increased by the Ca- (P < 0.01) and DON+ (P < 0.01) diet. After 13 d, feed conversion ratio (P < 0.01) and average daily feed intake (P = 0.06) tended to decrease with the Ca- diet. The bone mineral content (BMC) gain was decreased by Ca, especially with Ca- DON + (DON × Ca, P < 0.05). The P absorption was increased by Ca- DON + (DON × Ca, P < 0.01), although the P retention efficiency was only increased by Ca+ DON + (DON × Ca, P < 0.001). The absorption of Ca was increased by DON+ (P < 0.001), and the Ca efficiency was increased by Ca- DON- (DON × Ca, P < 0.01). After 9 d, the gene expression of intestinal claudin 12 (P < 0.01) and CYP24A1 (P < 0.05), femur cortical RANKL (P < 0.05) and OPG (P = 0.06), and renal calbindin D9K (P < 0.05) and Klotho (P = 0.07) were decreased by DON+. The Ca (P = 0.06) and magnesium (P < 0.01) concentrations were decreased by DON+, and the Ca (P = 0.06) and P digestibility (P < 0.01) were increased. After the repletion phase, Ca- piglets recovered their BMC deficit, but not those receiving DON+ (DON × Ca; P = 0.06). The Ca (P < 0.05) and P (P = 0.06) retention efficiency tended to increase with Ca-. The absorption of Ca and P was increased by Ca- and DON+ (DON × Ca, P < 0.05). The results show that piglets increased their Ca and P utilization efficiency, allowing them to recover the BMC deficit caused by Ca-, but not when the piglets were exposed to DON. Pigs previously receiving Ca-deficient diet with DON still have lower body Ca and P, leading to elevated calcitriol concentrations and enhanced Ca and P intestinal absorption. The fact that DON decreased the expression of genes implicated in Ca intestinal and renal transport and P excretion after 9 d can potentially explain the reduced plasma Ca concentration., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Efficient management of swine production systems requires understanding of complex reproductive physiological mechanisms. Our objective in this study was to investigate potential causal biological relationships between reproductive performance traits in high-producing gilts and sows. Data originated from a nutrition experiment and consisted of 200 sows and 440 gilts arranged in body weight blocks and randomly assigned to dietary treatments during late gestation at a commercial swine farm. Reproductive performance traits consisted of weight gain during late gestation, total number born and number born alive in a litter, born alive average birth weight, wean-to-estrous interval, and total litter size born in the subsequent farrowing. Structural equation models combined with the inductive causation algorithm, both adapted to a hierarchical Bayesian framework, were employed to search for, estimate, and infer upon causal links between the traits within each parity group. Results indicated potentially distinct reproductive networks for gilts and for sows. Sows showed sparse connectivity between reproductive traits, whereas the network learned for gilts was densely interconnected, suggesting closely linked physiological mechanisms in younger females, with a potential for ripple effects throughout their productive lifecycle in response to early implementation of tailored managerial interventions. Cross-validation analyses indicated substantial network stability both for the general structure and for individual links, though results about directionality of such links were unstable in this study and will need further investigation. An assessment of relative statistical power in sows and gilts indicated that the observed network discrepancies may be partially explained on a biological basis. In summary, our results suggest distinctly heterogeneous mechanistic networks of reproductive physiology for gilts and sows, consistent with physiological differences between the groups. These findings have potential practical implications for integrated understanding and differential management of gilts and sows to enhance efficiency of swine production systems. [ABSTRACT FROM AUTHOR]

Lowering the CP level in piglet diets reduces the risk of postweaning diarrhea and N excretion to the environment. The question remains at what point CP becomes limiting. An experiment was designed with 2 standardized ileal digestible (SID) Lys levels (10 and 11 g) and 6 CP levels (140, 150, 160, 170, 180, 190 g/kg) in a 2 × 6 factorial design (with 6 pens of 6 animals each per treatment). Linear and quadratic (QP) mixed models of performance in function of CP were fitted to study the effect of SID Lys and CP and their interaction. To determine optima, QP models and broken line models with linear (BLL) or quadratic (BLQ) ascending portions were fitted through the data. It was hypothesized 1) that the response to a decreasing digestible CP level could be described with broken line models and 2) that the break point of these models is dependent on the dietary SID Lys level. Decreasing the CP level decreased ADG (P < 0.001). For G:F, the effect of decreasing CP level depended on the SID Lys level (P of the interaction = 0.028 in the linear model and P = 0.002 in the QP model). According to the BLL model, with 11 g SID Lys in the diet, G:F started to decline with CP levels < 176 g CP [SID Lys:CP = 0.062, SID Lys:apparent total tract digestible (ATTD) CP = 0.077], and with 10 g SID Lys, CP levels < 165 g/kg (SID Lys:CP = 0.061, SID Lys:ATTD CP = 0.075) depressed performance. Serum creatinine levels showed a linear decrease with increasing SID Lys:CP levels (P < 0.001). Across both SID Lys levels, when fitting a BLL model, minimal serum urea levels were reached at an SID Lys:CP ratio of 0.064. This seems to be the point where CP and not Lys limits muscle deposition. The small difference in break point between serum urea level and performance suggests that the composition of nonessential AA may also be at stake. The effect of decreasing CP level depends on SID Lys, and using a maximal SID Lys:CP ratio may be useful for optimizing the AA profile of dietary CP. When the SID Lys:CP ratio exceeds 0.064 (SID Lys:ATTD CP > 0.079), protein and not individual AA limits growth in most piglets between 4 and 9 wk of age. [ABSTRACT FROM AUTHOR]

Feet and legs of replacement females were objectively evaluated at selection, i.e., approximately 150 d of age (n = 319) and post first parity, i.e., any time after weaning of first litter and before second parturition (n = 277) to 1) compare feet and leg joint angle ranges between selection and post first parity; 2) identify feet and leg joint angle differences between selection and first 3 wk of second gestation; 3) identify feet and leg joint angle differences between farms and gestation days during second gestation; and 4) obtain genetic variance components for conformation angles for the two time points measured. Angles for carpal joint (knee), metacarpophalangeal joint (front pastern), metatarsophalangeal joint (rear pastern), tarsal joint (hock), and rear stance were measured using image analysis software. Between selection and post first parity, significant differences were observed for all joints measured (P < 0.05). Knee, front and rear pastern angles were less (more flexion), and hock angles were greater (less flexion) as age progressed (P < 0.05), while the rear stance pattern was less (feet further under center) at selection than post first parity (only including measures during first 3 wk of second gestation). Only using post first parity leg conformation information, farm was a significant source of variation for front and rear pasterns and rear stance angle measurements (P < 0.05). Knee angle was less (more flexion; P < 0.05) as gestation age progressed. Heritability estimates were low to moderate (0.04-0.35) for all traits measured across time points. Genetic correlations between the same joints at different time points were high (>0.8) between the front leg joints and low (<0.2) between the rear leg joints. High genetic correlations between time points indicate that the trait can be considered the same at either time point, and low genetic correlations indicate that the trait at different time points should be considered as two separate traits. Minimal change in the front leg suggests conformation traits that remain between selection and post first parity, while larger changes in rear leg indicate that rear leg conformation traits should be evaluated at multiple time periods. [ABSTRACT FROM AUTHOR]

Due to increasing concerns about the use of antibiotic growth promoters (AGP) in livestock production and their complete ban in the European Union in 2006, suitable alternatives are urgently needed. Among others, anti-inflammatory activities of AGP are discussed as their putative mode of action. As numerous phytochemicals are known to modulate the cellular antioxidant capacity and immune response, we studied the antioxidative and anti-inflammatory properties of a phytogenic (plant-derived) feed additive (PFA) in intestinal porcine epithelial cells (IPEC-J2). The effects of the PFA were compared with those of selected phytogenic ingredients (grape seed extract [GRS], licorice extract [LIC], menthol [MENT], methyl salicylate [MES], oak bark extract [OAK], oregano essential oil [ORE], and a plant powder mix [PLA]), and with the effects of the AGP tylosin (TYL). Oxidative or inflammatory stress was induced by stimulating IPEC-J2 with hydrogen peroxide (H2O2; 0.5 mM) or tumor necrosis factor alpha (TNF-α; 10 ng/mL), respectively. The antioxidative effects of feed additives were assessed with a reactive oxygen species (ROS)-sensitive probe and by measuring the expression of 6 antioxidative target genes via quantitative real-time PCR (RT-qPCR). Anti-inflammatory potential was analyzed using a nuclear factor kappa- light-chain-enhancer of activated B cells (NF- κB) reporter gene assay. Moreover, the expression levels of 6 NF-κB target genes were measured using RT-qPCR analysis, and the release of IL-6 was analyzed via ELISA. Significant decreases in cellular ROS upon H2O2 treatment were observed for the PFA (P < 0.001), LIC (P < 0.001), ORE (P < 0.05), and GRS (P < 0.01). No significant changes in the expression of antioxidative genes were found. NF-κB activation upon TNF-α treatment was significantly inhibited by the PFA (P < 0.05) and by ORE (P < 0.001). Moreover, the PFA and ORE significantly reduced the gene expression of IL-6 (P < 0.001), IL-8 (P < 0.001), and C-C motif chemokine ligand 2 (CCL2; P < 0.05), as well as the release of IL-6 (P < 0.05). The other phytogenic compounds as well as the AGP TYL did not significantly affect any of the inflammatory parameters. In summary, we revealed the antioxidative properties of the PFA, LIC, ORE, and GRS, as well as anti-inflammatory properties of the PFA and ORE in IPEC-J2, providing a better understanding of the mode of action of this PFA under our experimental conditions. [ABSTRACT FROM AUTHOR]

Increased circulating lipopolysaccharide (LPS) results from heat stress (HS) and bacterial infection, both of which are associated with reduced female fertility. Specific effects of low-level, repeated LPS exposure on the ovary are unclear, as many studies utilize a bolus model and/or high dosage paradigm. To better understand the effects of chronic LPS exposure on ovarian signaling and function, post-pubertal gilts (n = 20) were orally administered altrenogest for 14 d to synchronize the beginning of the follicular phase of the ovarian cycle. For 5 d after synchronization, gilts (163 ± 3 kg) received IV administration of LPS (0.1 μg/kg BW, n = 10) or saline (CT, n = 10) 4× daily. Blood samples were obtained on days 1, 3, and 5 of LPS treatment. Follicular fluid was aspirated from dominant follicles on day 5, and whole ovarian homogenate was used for transcript and protein abundance analysis via quantitative real-time PCR and western blotting, respectively. There were no treatment differences detected in rectal temperature on any day (P ≥ 0.5). Administering LPS increased plasma insulin (P < 0.01), LPS-binding protein (LBP; P < 0.01), and glucose (P = 0.08) on day 1, but no treatment differences thereafter were observed (P = 0.66). There were no treatment differences in follicular fluid concentration of LBP or 17β-estradiol (P = 0.42). Gilts treated with LPS had increased abundance of ovarian TLR4 protein (P = 0.01), but protein kinase B (AKT) and phosphorylated AKT (pAKT) were unchanged and no effect of LPS on components of the phosphatidylinositol 3 kinase (PI3K) pathway were observed. There was no impact of LPS on ovarian abundance of STAR or CYP19A1, nor ESR1, LDLR, CYP19A1, CYP17A1, or 3BHSD. In conclusion, repeated, low-level LPS administration alters inflammatory but not steroidogenic or PI3K signaling in follicular phase gilt ovaries. [ABSTRACT FROM AUTHOR]

Heat shock protein 90 (Hsp90) functions as a molecular chaperone in its interaction with clients to influence multiple cellular and physiological processes. However, our current understanding on Hsp90's relationship with mammalian oocyte maturation is still very limited. Here, we aimed to investigate Hsp90's effect on pig oocyte meiotic maturation. Endogenous Hsp90a was constantly expressed at both mRNA and protein levels in porcine maturing oocytes. Addition of 2 µM 17-allylamino-17-demethoxygeldanamycin (17-AAG), the Hsp90 inhibitor, to in vitro mature cumulus-oocyte complexes (COC) significantly decreased Hsp90a protein level (P < 0.05), delayed germinal vesicle breakdown (GVBD) (P < 0.05), and impeded the first polar body (PB1) extrusion (P < 0.01) of porcine oocytes. 2 µM 17-AAG treatment during in vitro maturation also decreased the subsequent development competence as indicated by the lower cleavage (P < 0.001) and higher fragmentation (P < 0.001) rates of parthenotes, whereas no effects on the percentage and average cell number of blastocysts were found. Immunodepletion of Hsp90a by antibody microinjection into porcine oocytes at germinal vesicle and metaphase II stages induced similar defects of meiotic maturation and parthenote development, to that resulted from 2 µM inhibitor 17-AAG. For oocytes treated by 2 µM 17-AAG, the cytoplasm and membrane actin levels were weakened (P < 0.01), and the spindle assembly was disturbed (P < 0.05), due to decreased p-ERK1/2 level (P < 0.05). However, the mitochondrial function and early apoptosis were not affected, as demonstrated by rhodamine 123 staining and Annexin V assays. Our findings indicate that Hsp90a can couple with mitogen-activated protein kinase to regulate cytoskeletal structure and orchestrate meiotic maturation of porcine oocytes. [ABSTRACT FROM AUTHOR]

Heat stress (HS) pigs reduce their voluntary feed intake (VFI) and ingestion of indispensable amino acids (AA). Increasing the dietary crude protein (CP) content may help to correct the reduced AA intake by HS pigs, but it may further increase their body heat load. Increasing the AA intake by adding free AA to the diet does not affect the heat load of HS pigs. Two 21-d experiments were conducted. In Exp. 1, 30 pigs (31.1 ± 1.2 kg initial body weight) were used to determine the performance depression because of HS. Treatments were: thermo neutral pigs fed a 22% CP control diet (TN-C); HS pigs fed the control diet (HS-C); HS pigs fed a 14% CP, AA supplemented diet (HS-AA). HS pigs had lower ADG and Lys utilization efficiency, and consumed 20 and 25% less Lys and Thr, respectively, than the TN-C pigs (P < 0.05). In Exp. 2 (comparative slaughter), 25 pigs (33.6 ± 0.65 kg initial body weight) were used to evaluate the effect of extra dietary AA either as protein-bound or free AA on the performance and carcass traits of HS pigs. Treatments were: control wheat-SBM-free Lys, Thr and Met diet (CON); diet with 30% more CP than CON (HSxP); diet added with free AA to contain at least 25% more of each AA than the recommended level (HSxAA). Ambient temperature (AT) ranged from 27.7 to 37.7°C, and body temperature (39.9 to 41.2°C) followed a similar daily pattern as the AT did. There was no dietary treatment effect on daily feed and NE intake (P > 0.10), but the Lys, Thr, and Met intake was higher in pigs fed the HSxP or HSxAA diets than in pigs fed the CON diet (P < 0.05). The daily weight gain (ADG) was not affected (P > 0.10) but G:F tended to be higher and the Lys utilization efficiency (ADG, g/g Lys intake) tended to be lower in HSxP pigs than in CON pigs (P < 0.10). The HSxAA pigs had higher ADG (P < 0.05), and tended to have higher weight of hot carcass and leg muscle, and the weight gain of hot carcass and leg muscle than the CON pigs (P < 0.10). The weight and daily weight gain of loin muscle was higher in the HSxAA than in the HSxP pigs (P < 0.05). Kidney weight and serum urea in HSxP pigs were higher than in CON and HSxAA pigs, but spleen weight was higher in HSxAA pigs than in CON and HSxP pigs (P < 0.05). These results confirm that HS reduces the VFI, and show that increased levels of AA either as free or protein-bound do not additionally reduce the VFI of HS pigs. These also show that extra free AA supply rather than protein-bound AA better ameliorate the reduced growth performance of HS pigs. [ABSTRACT FROM AUTHOR]

Tail-end dehulling of canola meal (CM) has been shown to reduce dietary fiber and increase crude protein content in the dehulled meal. The application of this procedure also increased the total and non-phytate P content in the dehulled meal. However, it is unclear if dehulling affects P digestibility in the different fractions (i.e., the dehulled meal and the coarse fraction) and if it differs when fed to growing pigs at two different BW. Therefore, two experiments were conducted to determine the apparent (ATTD) and standardized (STTD) total tract digestibility of P in dehulled CM fed to growing pigs. Diets containing non-dehulled regular canola meal (RCM), and two fractions produced using sieve size of 355 pm: a low-fiber high-protein fraction (dehulled canola meal [DCM]) and a high-fiber low-protein fraction (coarse canola meal [CCM]) as the only source of P were fed to growing pigs at two different BW. A total of 48 pigs were used for the two experiments. In experiment 1, 24 barrows [(Yorkshire x Landrace) x Duroc] with initial BW of 24.5 ± 1.68 kg were individually housed in metabolism crates and fed the experimental diets for 10 d for total fecal collection. In experiment 2, 24 barrows with an average initial BW of 73.8 ± 4.93 kg were used; experimental diets and fecal collection procedures were the same as in experiment 1. Each experiment used six replicates per treatment. A P-free diet was used to determine basal endogenous losses of P (139.6 ± 10.7 and 150.89 ± 20.1 mg/kg of DMI for experiments 1 and 2, respectively). Data were analyzed as a completely randomized design. In experiment 1, the ATTD and STTD of P were greater (P < 0.05) for DCM (42.4% and 46.1%) than for the RCM (32.0% and 35.7%) and CCM (24.5% and 28.4%) diets. In experiment 2, the ATTD and STTD of P were greater (P < 0.05) for DCM (38.7% and 42.8%) than for the CCM diet (22.6% and 26.8%); whereas the values for RCM diet were intermediate (31.0% and 35.0%) and not different from the DCM and CCM. In conclusion, dehulling canola meal increased ATTD and STTD of P in growing pigs of different BW; however, there was no effect of BW. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of canola meal (CM) and to investigate the effects of basal diet [corn diet vs. corn-soybean meal (SBM) diet] and methodology (difference method vs. regression method) on energy values of CM. Thirty-six growing barrows (20.8 ± 1.0 kg initial body weight [BW]) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six experimental diets included a corn diet, a corn-SBM diet, a corn diet with 15 or 30% of CM, and a corn-SBM diet with 15 or 30% of CM. The DE, ME, and NE of CM were determined using the corn diet or the corn-SBM diet as a basal diet. In each basal diet, two additional diets containing 15 or 30% of CM were formulated to compare the determined energy values by the difference method and estimated energy values from the regression method. Feeding level was set at 550 kcal ME/kg BW0.6 per day. Pigs were fed experimental diets for 16 d including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24 h heat production (HP) and 12 h fasting HP. The DE, ME, and NE of CM determined by the difference method were within the 95% confidence intervals estimated for the DE, ME, and NE of CM by the regression method regardless of the basal diets used, which indicates that the difference and regression methods give equivalent DE, ME, and NE of CM. However, when the goodness of fit for the linear model was compared, the r² of the regression analysis from the corn-SBM diet (0.78) was relatively greater than that from corn diet (0.40). The estimated NE of CM by the prediction equations generated by either the corn diet or corn-SBM diets were 2,096 kcal/kg and 1,960 kcal/kg (as-fed basis), respectively, whereas those values determined by the difference method were 2,233 kcal/ kg and 2,106 kcal/kg (as-fed basis), respectively. In conclusion, the NE of CM determined in the current study was, on average, 2,099 kcal/kg (as-fed basis). The difference and regression methods do not give different NE value of CM fed to growing pigs. Although the NE values of CM determined using either the corn diet or the corn-SBM diet were not different, the greater r² of the regression analysis from the corn-SBM diet than that from the corn diet suggests that the corn-SBM diet is a more appropriate basal diet for NE determination of ingredients. [ABSTRACT FROM AUTHOR]

Brassica napus and Brassica juncea canola meal (CM) may replace soybean meal (SBM) in pig diets, but differ in fiber, glucosinolates content and profile. Preference of weaned pigs provided double-choice selections to diets containing 20% SBM, B. napus CM, or B. juncea CM was evaluated in two studies. In experiment 1, 216 pigs (9.4 ± 1.6 kg initial BW) were housed in 27 pens of 8 pigs (four gilts and four barrows). In experiment 2, 144 pigs (8.9 ± 1.1 kg) were housed in 36 pens of 4 pigs (two gilts and two barrows). Pigs were offered three dietary choices: B. napus CM with SBM as reference (B. napus CM [SBM]), B. juncea CM with SBM as reference (B. juncea CM [SBM]), and B. juncea CM with B. napus CM as reference (B. juncea CM [B. napus CM]) in a replicated 3 × 3 Latin square. Diets were formulated to provide 2.4 Mcal NE/kg and 4.5 g standardized ileal digestible Lys/Mcal NE and were balanced using canola oil and crystalline AA. Each pair of diets was offered in two self-feeders per pen as mash (experiment 1) or pellets (experiment 2) during three test-periods of 4-d, followed by a 3-d non-test period when a common diet was offered in both feeders. Feeders with different diets were rotated daily among pens during preference periods for both experiments, and feeder positions (right or left) were switched daily in experiment 2. Prior to the study and between periods, pigs were fed non-test diets containing SBM (experiment 1) or without test feedstuffs (experiment 2). Overall in both experiments, pigs preferred (P < 0.001) SBM over B. napus and B. juncea CM diets, and preferred (P < 0.001) B. napus over B. juncea CM diet. Dietary choice did not affect (P > 0.05) growth performance in both experiments, except for greater G:F (P < 0.05) for pigs fed the B. juncea CM [B. napus CM] diets than pigs fed the B. napus CM [SBM] or B. juncea CM [SBM] diets in experiment 1. In conclusion, weaned pigs preferred SBM over CM diets when given a choice, and preferred B. napus over the B. juncea diet that contained more total glucosinolates especially gluconapin. Weaned pigs fed the B. juncea CM [B. napus CM] diets in the double-choice selection did not reduce feed intake, weight gain, and G:F compared to pigs fed the B. napus CM [SBM] or B. juncea CM [SBM] diets. [ABSTRACT FROM AUTHOR]

A total of 239 pigs (initial BW 6.56 ± 0.87 kg, 21 d of age) were used in a 35-d study to investigate the effects of fish meal (FM) and spray dried plasma (SDP) in combination with a bioprocessed soybean meal (SBM) on growth performance and immune responses in weaned pigs. Equal numbers of barrows and gilts were randomly allotted to 1 of 4 dietary treatments (10 pens/treatment) according to initial BW and sex: positive control (CON; corn/SBM diet) containing SDP and FM, the CON with bioprocessed SBM replacing FM (BPSBM+SDP), the CON with bioprocessed SBM replacing SDP (BPSBM+FM), and the CON with bioprocessed SBM replacing both SDP and FM (BPSBM). Experimental diets were fed in Phase I (d 1-7 post-wean) and II (d 8-21) followed by a common Phase III diet (d 22-35); changes in BW and feed disappearance were determined accordingly. Pigs were sensitized against ovalbumin (OVA) and Candida albicans (CAA) on d 7 and 21. Assessment of immune response was based on lymphocyte proliferation in response to mitogens Concanavalin A and phytohemagglutinin (d 14 post-wean), dermal hypersensitivity to OVA and CAA (% increase in local swelling at 2, 6, 24, and 48 h post-injection) on d 28, and primary and secondary anti-OVA IgG at d 21 and 28, respectively. Pigs fed CON were heavier (P < 0.01) than pigs fed BPSBM+FM and BPSBM, and not different from pigs fed BPSBM+SDP, at the end of Phase I and II (6.99, 6.80, 6.52, or 6.60 kg, pooled SEM 0.08, respectively in Phase I or 12.47, 12.18, 11.42, and 11.85 kg, pooled SEM 0.21, in Phase II, respectively). Hypersensitivity to OVA peaked at 2h in pigs fed CON, BPSBM+SDP, and BPSBM+FM or peaked at 6h in pigs fed BPSBM (121.4, 165.6, 139.0, and 144.1%, pooled SEM 22.9, respectively, at 2 h and 86.7, 114.5, 95.0, and 156.8%, pooled SEM 29.4, respectively at 6 h). Peak response to CAA occurred at 2h in all groups (42.6, 55.2, 48.2, and 50.6%, pooled SEM 11.9, respectively, in the CON, BPSBM+SDP, BPSBM+FM, and BPSBM, respectively). There was no difference in hypersensitivity due to experimental diet at any time point. Secondary anti-OVA IgG was 2-fold lower based on optical density values in pigs fed CON compared with BPSBM+FM and BPSBM (0.78 vs. 1.56 and 1.55 optical density at 405 nm, pooled SEM 0.42, respectively). Dietary treatment did not impact lymphocyte proliferation. The bioprocessed SBM is a suitable alternative for FM and/or SDP in Phase I and II nursery diets based on pig growth. The prolonged hypersensitivity to OVA indicate that bioprocessed SBM may have a positive impact on pig immune function and the 2-fold increase in anti-OVA IgG warrants further investigation on the impact of bioprocessed SBM on pig immune function. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to determine the effects of viscosity and fermentability of purified nonstarch polysaccharides (NSP) on intestinal nutrient and energy flow and hindgut fermentation in growing pigs. In Exp. 1, 15 ileal-cannulated pigs (50.5 ± 2.9 kg BW) were allotted to 5 diets in a 2-period incompletely randomized design. Pigs were provided a cornstarch N-free diet (CST) or a diet containing 5% inulin (INU), carboxymethylcellulose sodium (CMC), microcrystalline cellulose (MCC), or Solka-Floc (SFC). Apparent ileal digestibility (AID) of DM, ash, and GE were greater (P < 0.05) in the MCC and SFC diets than in the INU and CMC diets. Apparent total tract digestibility (ATTD) of DM, carbohydrates (CHO), and GE and the DE content in the CST and INU diets were greater (P < 0.01) than in the CMC, MCC, and SFC diets. Hindgut disappearance of DM, CHO, and GE in the INU diet was greater (P < 0.05) than in the other N-free diets. The ileal endogenous flow of His, Ile, Leu, Met, Thr, Val, and all dispensable AA in the CMC diet was greater (P < 0.05) than in the other diets. In Exp. 2, 6 ileal-cannulated pigs were allotted to 3 diets containing either a corn-soybean meal control diet or the control diet with 5% INU or CMC in a replicated 3 × 3 Latin square design. Standardized ileal digestibility (SID) of Ala, Arg, Asp, Cys, Gly, His, Ile, Leu, Lys, Phe, Ser, Thr, and Val were greater (P < 0.05) in the CMC diet than in the control and INU diets. Incorporation of 5% INU or CMC in the control diet reduced (P < 0.01) the AID of arabinoxylan and insoluble and total NSP. The ATTD of NSP and cellulose and the hindgut disappearance of NSP, ß-glucan, and cellulose in the CMC diet were less (P < 0.01) than in the control and INU diets. Inclusion of 5% INU in the diet increased (P < 0.01) hindgut fermentation of insoluble and total NSP compared with the control and CMC diets. In conclusion, depending on the viscosity and fermentability of the NSP, different sources will have different effects on nutrient digestibility and hindgut fermentation. Addition of 5% INU to a corn-soybean meal diet reduced digestibility of the NSP component in the ileum and increased hindgut fermentation of total NSP. In contrast, the inclusion of CMC increased the AID and SID of the diet and reduced total tract digestion and hindgut fermentation of NSP component. Carboxymethylcellulose sodium is not recommended as a source of synthetic fiber in a N-free diet to determine the SID of AA of diets. [ABSTRACT FROM AUTHOR]

Microcin J25 (MccJ25) is an antimicrobial peptide produced by a fecal strain of Escherichia coli containing 21 AA. This study was performed primarily to evaluate the effects of MccJ25 as a potential substitute for antibiotics (AB) on growth performance, nutrient digestibility, fecal microbiota, and intestinal barrier function in weaned pigs. In the present study, 180 weaned pigs (7.98 ± 0.29 kg initial BW) were randomly assigned to 1 of 5 treatments, including a basal diet (CON) and CON supplemented with AB (20 mg/kg colistin sulfate; ABD) or 0.5, 1.0, and 2.0 mg/kg MccJ25. On d 0 to 14, dietary supplementation with MccJ25 and ABD had positive effects on ADG, ADFI, diarrhea incidence, and G:F (P < 0.05). Pigs fed the 2.0 mg/kg MccJ25 diet had greater ADG (P < 0.05) and marginally greater G:F (P < 0.10) compared with pigs fed the ABD diet. Compared with the CON diet, the 2.0 mg/kg MccJ25 diet sharply improved (P < 0.05) ADG and G:F and decreased (P < 0.05) diarrhea incidence (d 15 to 28 and d 0 to 28). Apparent digestibility of nutrients in pigs fed 1.0 and 2.0 mg/kg MccJ25 was improved (P < 0.05) compared with that of pigs fed CON and ABD. The serum cytokines IL-6 and IL-1β and tumor necrosis factor-a levels in pigs fed MccJ25 were greater than in pigs fed CON (P < 0.05). Additionally, the IL-10 concentration in pigs fed MccJ25 was sharply increased (P < 0.05) compared with that of pigs fed CON. Pigs fed 1.0 and 2.0 mg/kg MccJ25 diets had remarkably decreased d-lactate, diamine oxidase, and endotoxin concentrations and fecal E. coli numbers (P < 0.05) and improved fecal Lactobacillus and Bifidobacterium numbers (P < 0.05). Compared with the ABD diet, the diet containing 2.0 mg/kg MccJ25 did not increase d-lactate, diamine oxidase, and endotoxin (d 14) concentrations (P < 0.05) or decrease the Lactobacillus and Bifidobacterium (d 28) numbers (P < 0.05). The diets containing 1.0 and 2.0 mg/kg MccJ25 and ABD (d 28) improved lactate concentration and short-chain fatty acid concentrations, including acetate, propionate, and butyrate, in feces (P < 0.05). Moreover, the pigs fed 2.0 mg/kg MccJ25 had greater lactate, butyrate (d 14), and propionate concentrations than the pigs fed the ABD diet (P < 0.05). In conclusion, dietary supplemented MccJ25 effectively improved performance, attenuated diarrhea and systematic inflammation, enhanced intestinal barrier function, and improved fecal microbiota composition of weaned pigs. Therefore, MccJ25 could be a potential effective alternative to AB for weaned pigs. [ABSTRACT FROM AUTHOR]

The present study was designed to evaluate the effects of dietary betaine on pig performance and serological and hematological indices during thermoneutral and heat-stressed conditions. Individually housed pigs (n = 64; 39.0 ± 1.5 kg BW) were assigned within weight blocks and sex to 1 of 8 treatments. Treatments consisted of 2 environmental conditions (thermoneutral or heat-stressed) and 4 levels of betaine (0, 0.10, 0.15, and 0.20%). Room temperatures followed a daily pattern with a low of 14°C and a high of 21°C for the thermoneutral environment and a low of 28°C and a high of 35°C for the heat-stressed environment. Experimental diets were fed from d -7 (7 d prior to imposing temperature treatments; constant 21°C) until 28. Respiration rate and rectal temperature were measured on d 0, 1, 2, 3, 7, 14, 21, and 28, and blood samples were collected on d 3 and 28. Heat stress reduced (P = 0.008) ADG (0.710 vs. 0.822 kg/d) and ADFI (1.81 vs. 2.27 kg/d) and increased G:F (P = 0.036; 0.391 vs. 0.365). Betaine tended to quadratically increase G:F (P = 0.071; 0.377, 0.391, 0.379, and 0.366 for 0, 0.10, 0.15, and 0.20% betaine, respectively), regardless of environment. Heat stress increased (P = 0.001) respiration rate (48 vs. 23 breaths/30 s) and rectal temperature (39.47 vs. 38.94°C) throughout d 1 to 28. Betaine at 0.10% reduced rectal temperature in heat-stressed pigs but not in control pigs (interaction, P = 0.040). Heat stress increased serum cysteine and triglycerides and reduced Ca, alkaline phosphatase, and lipase, regardless of day of sampling (P = 0.048). Heat stress increased serum creatine phosphokinase (CPK) and K and reduced osmolarity, Na, urea N, methionine, homocysteine, the albumin:globulin ratio, and blood eosinophil count on d 3 but not on d 28 (interaction, P = 0.013). Heat stress increased serum Mg, globulin, creatinine, amylase, and γ-glutamyltranspeptidase and reduced P, the urea N:creatinine ratio, alanine aminotransferase, NEFA, hemoglobin, hematocrit, and red blood cells on d 28 but not on d 3 (interaction, P = 0.034). Betaine increased serum osmolarity and NEFA and reduced CPK and K on d 3 but not on d 28 (interaction, P = 0.060) and increased serum creatinine and reduced amylase on d 28 but not on d 3 (interaction, P = 0.057). Heat stress reduced growth, disturbed ion balance, and increased markers of muscle damage. Betaine had a minor impact on alleviating heat stress with the possible exception of early days of heat exposure. The beneficial effect of betaine was diminished by pig adaptation. [ABSTRACT FROM AUTHOR]

Progeny of GPK-35 females mated to PIC 380 boars were blocked by initial BW, and within the 9 blocks, pens of pigs (3 gilts and 3 barrows/pen) were randomly assigned to dietary treatments where CP of finisher-I, -II, and -III diets was 1) 16.04, 14.55, and 16.23%, respectively (Ctrl); 2) 14.76, 13.48, and 15.27%, respectively (ILE); 3) 14.26, 12.78, and 14.28%, respectively (VAL); or 4) 12.65, 12.38, and 13.32%, respectively (NoSBM). All finisher-III diets included 10 mg/kg of ractopamine hydrochloride (RAC) and a Lys:ME ratio of 2.79 g/Mcal. At slaughter, HCW and Fat-O-Meat'er data were recorded before carcasses were subjected to a rapid chilling process. A subsample of whole hams (2/pen) and whole loins (2/pen) were transported under refrigeration to the University of Arkansas. Hams were dissected with a knife into lean, fat, and bone, and 2.5-cm-thick chops from the semimembranosus (SM) and the LM were used to measure fresh pork quality characteristics. Both ADG and G:F decreased (linear, P = 0.05) as CP decreased in finisher-I diets, whereas ADFI was reduced (linear, P = 0.01) in response to decreasing CP in finisher-II diets. When RAC was included in the finisher-III diets, ADFI and BW decreased (linear, P = 0.03) with decreasing CP, and pigs fed the ILE diet had greater (cubic, P < 0.01) G:F than pigs fed the Ctrl and VAL diets. Across the entire finishing period, ADG and ADFI decreased (linear, P = 0.01) in response to reductions in dietary CP. Conversely, reducing CP in finisher diets did not (P = 0.13) affect carcass yield, fat depth, LM depth, or calculated fat-free lean yield, and dietary CP content did not (P = 0.09) alter the lean, fat, or bone composition of fresh hams. Moreover, there was no effect of dietary CP on the visual and instrumental color or firmness of the LM (P = 0.06) or SM (P = 0.12). However, there were linear increases in LM marbling scores (P = 0.02) and intramuscular fat content (P = 0.03) as CP was reduced in the finisher diets. Although reducing dietary CP decreased overall ADG and ADFI by approximately 6.1 and 4.9%, respectively, carcass composition was not impacted by dietary CP level. More importantly, reducing dietary CP, although meeting the standard ileal digestible requirements for Lys, Thr, Trp, Met, Ile, and Val with crystalline AA, did not impact pork color or water-holding capacity and actually increased the intramuscular fat content of the LM. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of dietary chromium, CLA, and ractopamine on performance, carcass traits, and pork quality of finishing pigs slaughtered at 115 kg BW. Ninety-six crossbred barrows (initial BW = 70.21 ± 1.98 kg) were randomly assigned to 1 of 6 dietary treatments. There were 8 replicates per treatment (48 pens; 2 pigs/pen). A diet formulated according to the nutritional requirements was used as the control (CON). The other 5 diets were based on the CON and supplemented as follows: 0.4 mg/kg Cr yeast (CrY); 0.5% CLA; 0.4 mg/kg CrY and 0.5% CLA (CrY + CLA); 20 mg/kg ractopamine (RAC); 0.4 mg/ kg CrY and 20 mg/kg RAC (CrY + RAC). Lysine levels on diets containing ractopamine were raised by 20% compared to CON to meet the greater requirements of pigs fed ractopamine. Pigs fed RAC and CrY + RAC were fed CON for the first 17 d, and then the respective diets for the last 28 d on trial. Data were analyzed in a model including the fixed effect of treatment (6 levels) and initial BW as a covariate for all characteristics, with the exception of carcass traits, in which final BW was used as a covariate. Least-squares means were separated using Tukey-Kramer's method. Differences were considered when probability values were lower than 0.05. Pigs fed RAC and CrY + RAC had the greatest (P < 0.001) final BW and ADG. Pigs fed CrY + RAC had greater (P < 0.001) G:F than pigs within the other groups, except for those fed RAC. Pigs fed CrY + RAC and RAC had similar G:F, both greater (P < 0.001) than pigs fed CON. Average daily feed intake was similar (P = 0.83) for all diets. Pigs fed CrY + RAC had greater LM area (P = 0.01) and carcass yield (P < 0.02) than pigs fed CON, CrY, CLA, and CrY + CLA. Loin muscle area and carcass yield of pigs fed RAC were not different from pigs fed the others diets. Pigs fed CON diets had greater BF (P = 0.02) than pigs fed CLA diet. Additives did not affect (P > 0.05) pork quality, except for color. No differences (P > 0.05) were observed for carcasses pH and temperature. The L* values for pigs fed RAC were greater (P = 0.01) than pigs fed other diets. Pigs fed RAC had lower (P < 0.01) a* values compared to pigs fed other experimental diets. Serum urea nitrogen concentration (SUN) was lower (P = 0.02) in pigs fed CrY + RAC than in pigs fed CON and RAC and similar to pigs fed the other feeding additives. In summary, it was demonstrated that, when combined, CrY and RAC increase LM area and carcass yield, and reduce SUN, suggesting that chromium could improve nutrient utilization by muscle cells in RAC-fed pigs. Additionally, the additives have no major effects on pork quality. [ABSTRACT FROM AUTHOR]

A total of 1,143 pigs (PIC 337 x 1050, initially 25.1 ± 0.03 kg BW) were used in a 111-d study to determine the effects of copper sulfate (CuSO4; Prince Agri-Products, Quincy, IL) or tribasic copper chloride (TBCC; IntelliBond C; Micronutrients, Indianapolis, IN) on growth performance, carcass characteristics, and pen cleanliness. Pens of pigs were allotted to 1 of 6 dietary treatments, balanced on average pen weight in a randomized complete block design with 25 to 28 pigs per pen and 7 replications per treatment. Treatments included a corn--soybean meal--based diet (corn-soy), a high-by-product diet with 30% distillers dried grains with solubles and 15% bakery meal (byproduct diet), and the by-product diet with 75 or 150 mg/kg added Cu from CuSO4 or TBCC. All diets contained 20 mg/kg Cu from CuSO4 in the trace mineral premix. At the conclusion of the trial, a digital photo of each pen was taken to allow 3 independent observers to score manure texture and buildup and to assess pen cleanliness prior to power washing. Furthermore, the time required to power wash each pen was also measured. Overall, pigs fed the by-product diet tended to have increased ADFI (P = 0.083) and had decreased G:F (P = 0.005) compared to those fed the corn-soy diet. No Cu source x level interactions or Cu source differences were observed (P > 0.05). From d 0 to 71, pigs fed increasing Cu had increased (quadratic, P < 0.05) ADG, d 71 BW, and ADFI. From d 71 to 111, pigs fed increasing Cu tended to have increased ADFI (linear, P = 0.068) and decreased G:F (quadratic, P = 0.056). Overall (d 0 to 111), increasing Cu increased (linear, P < 0.01) ADG, final BW, and ADFI (quadratic, P = 0.026). Hot carcass weight increased (linear, P = 0.023) by 2.4 kg with increasing Cu. Increasing Cu also increased loin depth (linear, P = 0.019) and percentage lean (quadratic, P = 0.024). Manure buildup and wash time (s/pen) increased (P < 0.05) for by-product diet pens compared to corn-soy pens; however, neither wash time nor pen cleanliness were influenced by added Cu. In summary, increasing dietary Cu in high-by-product diets improved growth and feed intake, resulting in increased final BW and HCW for pigs fed both Cu sources, without influencing pen wash time. [ABSTRACT FROM AUTHOR]

To study the effects of diet complexity and multicarbohydrase (MC) supplementation, 144 piglets (6.70 ± 0.81 kg of BW) weaned at 21 ± 2 d of age (1:1 male to female ratio) were assigned to 1 of 6 dietary treatments in a 3 x 2 factorial arrangement based on diet complexity (complex1, complex2, and simple) and MC addition (0 vs. 0.1% of MC). Diets were provided in a 2-phase feeding program with phase I (d 1 to 14) and phase II diets (d 15 to 28). Complex1 was formulated to mimic a conventional weaner diet with blood plasma, fish meal, dried whey, and skim milk powder, whereas complex2 partially or totally replaced these ingredients with various plant-based ingredients. The simple diet primarily comprised corn, wheat, and soybean meal. No interactions were found between diet complexity and MC supplementation (P > 0.10), except for apparent total tract digestibility (ATTD) of ash and globulin concentration on d 28 (P < 0.05). Pigs fed the complex1 diet had greater (P < 0.01) ADG, ADFI, and G:F than those fed the other diets during the first week after weaning. However, no differences in ADG or ADFI were observed for pigs fed the complex1 and simple diets throughout the 28-d experimental period (P > 0.10), whereas the complex2 diet led to lower ADG and ADFI compared with the complex1 diet (P < 0.05). Overall, G:F was greater for pigs fed the simple diet compared with those fed the complex1 diet (P < 0.01). Pigs fed the simple diet showed ATTD of DM, OM, GE, and ash comparable to those fed the complex1 diet on d 14 (P > 0.10). In contrast, greater ATTD of DM, OM, NDF, GE, and ash was observed (P < 0.05) in pigs fed the complex1 diet than in those fed the complex2 diet or the simple diet on d 28. The simple diet increased the lymphocyte proportion in serum compared with the complex1 diet (P < 0.01) on d 14. Pigs fed the complex1 diet had a greater (P < 0.05) ratio of villus height (VH) to crypt depth (CD) in the ileum compared with the other diets. The complex2 diet decreased (P < 0.05) the fecal score during 3 wk of the postweaning period compared with the complex1 diet. Dietary MC supplementation increased (P < 0.05) G:F during the overall experimental period, VH in the ileum, VH:CD ratio in the duodenum, and ATTD of DM and GE but it reduced fecal score (P < 0.05). In conclusion, feeding a simple diet resulted in BW comparable to feeding the complex1 diet, but it led to inferior intestinal morphology and ATTD of nutrients on d 28. Also, MC supplementation could be beneficial regardless of diet complexity. [ABSTRACT FROM AUTHOR]

The objective of the present study was to estimate genetic co-variance parameters pertaining to live weight, feed intake, and 2 efficiency traits (i.e., residual feed intake and residual daily gain) in a population of pigs over a defined growing phase using Legendre polynomial equations. The data set used consisted of 51,893 live weight records and 903,436 feed intake, residual feed intake (defined as the difference between an animal's actual feed intake and its expected feed intake), and residual daily gain (defined as the difference between an animal's actual growth rate and its expected growth rate) records from 10,201 growing pigs. Genetic co-variance parameters for all traits were estimated using random regression Legendre polynomials. Daily heritability estimates for live weight ranged from 0.25 ± 0.04 (d 73) to 0.50 ± 0.03 (d 122). Low to moderate heritability estimates were evident for feed intake, ranging from 0.07 ± 0.03 (d 66) to 0.25 ± 0.02 (d 170). The estimated heritability for residual feed intake was generally lower than those of both live weight and feed intake and ranged from 0.04 ± 0.01 (d 96) to 0.17 ± 0.02 (d 159). The heritability for feed intake and residual feed intake increased in the early stages of the test period and subsequently sharply declined, coinciding with older ages. Heritability estimates for residual daily gain ranged from 0.26 ± 0.03 (d 188) to 0.42 ± 0.03 (d 101). Genetic correlations within trait were strongest between adjacent ages but weakened as the interval between ages increased; however, the genetic correlations within all traits tended to strengthen between the extremes of the trajectory. Moderate to strong genetic correlations were evident among live weight, feed intake, and the efficiency traits, particularly in the early stage of the trial period (d 66 to 86), but weakened with age. Results from this study could be implemented into the national genetic evaluation for pigs, providing comprehensive information on the profile of growth and efficiency throughout the growing period of the animal's life, thus helping producers identify genetically superior animals. [ABSTRACT FROM AUTHOR]

Life cycle assessment (LCA) has been used in many studies to evaluate the effect of feeding strategy on the environmental impact of pig production. However, because most studies have been conducted in European conditions, the question of possible interactions with the context of production is still under debate. The objective of this study was to evaluate these effects in 2 contrasted geographic contexts of production, South America (Brazil) and Europe (France). The LCA considered the process of pig fattening, including production and transport of feed ingredients and feed, raising of fattening pigs, and manure storage, transport, and spreading. Impacts were calculated at the farm gate, and the functional unit considered was 1 kg of BW gain over the fattening period. The performances of pigs were simulated for each scenario using the InraPorc population model (2,000 pigs per scenario considering between-animal variability). The LCA calculations were performed for each pig according to its own performance and excretion, and the results were subjected to variance analysis. The results indicate that for some impacts there are clear interactions between the effects of the feeding program, the origin of soybean, and the location of production. For climate change, interest in phase feeding and incorporation of crystalline AA (CAA) is limited and even counterproductive in Brazil with soybeans from the South (without deforestation), whereas they appear to be efficient strategies with soybeans from the Center West (with deforestation), especially in France. Rather similar effects, as those for climate change, were observed for cumulative energy demand. Conversely, potential eutrophication and acidification impacts were reduced by phase feeding and CAA addition in a rather similar way in all situations. Individual daily feeding, the only strategy that took into account between-animal variability, was the most effective approach for reducing the life cycle impact of pig fattening in all situations, whereas the potential of phase feeding programs and CAA was dependent on soybean origin and the geographical context of pig production, in contrast with previous results. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the impact of seasonal losses due to heat stress in different environments and genetic group combinations. Data were available for 2 different swine populations: purebred Duroc animals raised in nucleus farms in Texas and North Carolina and crosses of Duroc and F1 females (Landrace × Large White) raised in commercial farms in Missouri and North Carolina; pedigrees provided links between animals from different states. Traits included BW at harvest age for purebred animals and HCW for crossbred animals. Weather data were collected at airports located close to the farms. Heat stress was quantified by a heat load function, defined by the units of temperature-humidity of temperature–humidity index (THI) greater than a certain threshold for 30 to 70 d before phenotype collection. Heat stress responses were quantified by a linear regression of phenotype on heat load. The greatest coefficient of determination occurred with a length of 30 d before phenotype measurements for all states and genetic groups. In the crossbreed data, THI thresholds were 67 in Missouri and 72 in North Carolina. For pure breeds, heat load had the best fit for THI thresholds greater than 70 in North Carolina, although differences in coefficient of determinations were negligible. On the other hand, no optimal THI threshold existed in Texas. In this study, heat stress had a greater impact in commercial farms than in nucleus farms and the effect of heat stress on weight varied by year and state. [ABSTRACT FROM AUTHOR]

Heat stress (HS) results in major losses to the pork industry via reduced growth performance and, possibly, carcass fat quality. The experimental objective was to measure the effects of HS on the pig’s response to dietary fat in terms of lipid digestion, metabolism, and deposition over a 35-d finishing period. A total of 96 PIC 337 × C22/C29 (PIC, Inc., Hendersonville, TN) barrows (initial BW of 100.4 ± 1.2 kg) were randomly allotted to 1 of 9 treatments arranged as a 3 × 3 factorial: thermoneutral (TN; constant 24°C; ad libitum access to feed), pair-fed thermoneutral (PFTN; constant 24°C; limit fed based on previous HS daily feed intake), or HS (cyclical 28°C nighttime, 33°C from d 0 to 7, 33.5°C from d 7 to 14, 34°C from d 14 to 21, 34.5°C from d 21 to 28, and 35°C from d 28 to 35 daytime; ab libitum access to feed) and diet (a corn–soybean meal–based diet with 0% added fat [CNTR], CNTR with 3% added tallow [TAL; iodine value {IV} = 41.8], or CNTR with 3% added corn oil [CO; IV = 123.0]). No interactions between environment and diet were evident for any major response criteria (P ≥ 0.063). Rectal temperature increased due to HS (39.0°C for HS, 38.1°C for TN, and 38.2°C for PFTN; P < 0.001). Heat stress decreased ADFI (27.8%; P < 0.001), ADG (0.72 kg/d for HS, 1.03 kg/d for TN, and 0.78 kg/d for PFTN; P < 0.001), and G:F (0.290 for HS, 0.301 for TN, and 0.319 for PFTN; P = 0.006). Heat stress barrows required 1.2 Mcal of ME intake more per kilogram of BW gain than PFTN (P < 0.001). Heat stress tended to result in the lowest apparent total tract digestibility of acid hydrolyzed ether extract (AEE; 59.0% for HS, 60.2% for TN, and 61.4% for PFTN; P = 0.055). True total tract digestibility (TTTD) of AEE of CO-based diets (99.3%) was greater than that of CNTR (97.3%) and TAL-based diets (96.3%; P = 0.012). Environment had no impact on TTTD of AEE (P = 0.118). Environment had no impact on jowl IV at market (69.2 g/100 g for HS, 69.3 g/100 g for TN, and 69.8 g/100 g for PFTN; P = 0.624). Jowl IV at market increased with increasing degree of unsaturation of the dietary fat (68.5 g/100 g for CNTR, 68.2 g/100 g for TAL, and 71.5 g/100 g for CO; P < 0.001). Heat stress decreased mRNA abundance of ATGL and HSL (P ≤ 0.041). Heat stress and CO increased mRNA abundance of SCD (P ≤ 0.047), and CO increased abundance of FASN (P = 0.011). In conclusion, HS does not alter the pig’s response to dietary fat. However, HS leads to reduced ADG, ADFI, G:F, and caloric efficiency and a suppression of mRNA abundance of genes involved in the lipolytic cascade, which resulted in a phenotype that was fatter than PFTN. [ABSTRACT FROM AUTHOR]

The present work was conducted to determine, via a summary of data from peer-reviewed publications, if differences in the standardized ileal digestibility (SID) of CP and AA in different soy proteins exist when fed to pigs and to determine if the BW of pigs influences the SID of CP and AA. The following ingredients were included in the analysis: dehulled soybean meal (SBM) with 46 to 48% CP (SBM 48%), non-dehulled SBM with a CP concentration of 42 to 44% (SBM 44%), enzyme-treated SBM (ESBM), fermented SBM (FSBM), soy protein concentrate (SPC), and soy protein isolate (SPI). Results indicated that the SID of most AA was not different between SBM 48% and SBM 44%; however, for some AA, greater (P < 0.05) SID values in ESBM, SPC, and SPI were obtained compared with SBM 48%, SBM 44%, and FSBM. The least (P < 0.05) SID of Lys was observed in FSBM, which also had the least Lys-to-CP ratio, indicating that FSBM sometimes is exposed to excessive heat damage during drying of the fermented product. For SBM 48%, it was also possible to analyze the effect of pigs' BW on the SID of CP and AA. Results indicated that the SID of CP and AA were less (P < 0.05) in pigs of BW less than 20 kg compared with pigs of BW above 20 kg. Therefore, it can be concluded that differences in SID of CP and AA among soy proteins exist and that for SBM 48%, SID values may be less in pigs less than 20 kg than in pigs above 20 kg. [ABSTRACT FROM AUTHOR]