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Vitamin D3 (Vit D3) and 25(OH)D3 are used as dietary sources of active vitamin D (1,25(OH)2D3) in pig husbandry. Although acting primarily on intestine, kidney and bone, their use in pig nutrition has shown a wide range of effects also in peripheral tissues. However, there is an ambiguity in the existing literature about whether the effects of Vit D3 and 25(OH)D3 differ in attributing the molecular and phenotypic outcomes in pigs. We searched Web of Science and PubMed databases concerning the efficacy of Vit D3 in comparison with 25(OH)D3 on pig physiology, i.e. reproductive capacities, growth performance, immunity and bone development. Dietary intake of Vit D3 or 25(OH)D3 did not influence the reproductive capacity of sows. Unlike Vit D3, the maternal intake of 25(OH)D3 significantly improved the growth performance of piglets, which might be attributed to maternally induced micronutrient efficiency. Consequently, even in the absence of maternal vitamin D supplementation, 25(OH)D3-fed offspring also demonstrated better growth than the offspring received Vit D3. Moreover, a similar superior impact of 25(OH)D3 was seen with respect to serum markers of innate and humoral immunity. Last but not least, supplements containing 25(OH)D3 were found to be more effective than Vit D3 to improve bone mineralisation and formation, especially in pigs receiving basal diets low in Ca and phosphorus. The insights are of particular value in determining the principal dietary source of vitamin D to achieve its optimum utilisation efficiency, nutritional benefits and therapeutic potency and to further improve animal welfare across different management types. [ABSTRACT FROM AUTHOR]

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Dielectric barrier discharge (DBD) plasma regulates the levels of reactive oxygen species (ROS), which are critical for sperm quality. MicroRNAs (miRNAs) are non-coding single-stranded RNA molecules encoded by endogenous genes, which regulate post-transcriptional gene expression in animals. At present, it is unknown whether DBD plasma can regulate sperm ROS levels through miRNAs. To further understand the regulatory mechanism of DBD plasma on sperm ROS levels, miRNAs in fresh boar spermatozoa were detected using Illumina deep sequencing technology. We found that 25 known miRNAs and 50 novel miRNAs were significantly upregulated, and 14 known miRNAs and 74 novel miRNAs were significantly downregulated in DBD plasma-treated spermatozoa. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that target genes of differentially expressed miRNAs were involved in many activities and pathways associated with antioxidants. We verified that DBD plasma significantly increased boar sperm quality and reduced ROS levels. These results suggest that DBD plasma can improve sperm quality by regulating ROS levels via miRNAs. Our findings provide a potential strategy to improve sperm quality through miRNA-targeted regulation of ROS, which helps to increase male reproduction and protect cryopreserved semen in clinical practice., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Single Layer Centrifugation (SLC) through a low density colloid offers an alternative solution to antibiotic use in boar semen extenders, with lower costs compared to high density colloids. The aim of this study was to explore the reproductive performance of sows when using SLC-prepared semen doses without antibiotics, employing low density Porcicoll to prepare semen doses for artificial insemination in a commercial swine herd in Thailand. Ejaculates were divided into two equal parts to create insemination doses, with each dose containing 3000 × 10 6 sperm/80 ml for intra-uterine insemination in individual sows. The sows were inseminated twice, with the interval between the two inseminations ranging from 8 to 16 h. The CONTROL group consisted of 206 semen doses treated with antibiotics, prepared for insemination in 103 sows, while the SLC group comprised 194 SLC-prepared semen doses without antibiotics for inseminating 97 sows. Fertility and fecundity traits, including non-return rate, conception rate, farrowing rate, and litter traits (i.e., the total number of piglets born per litter, number of piglets born alive per litter, number of stillborn piglets, and number of mummified fetuses), were compared between groups. Furthermore, data on piglet characteristics, including live-born and stillborn piglets (i.e., the prevalence of stillbirth (yes, no), birth weight, crown-rump length, body mass index (BMI), and ponderal index (PI)), were determined. No significant differences in non-return rate (75.7 % vs. 77.3 %), conception rate (73.8 % vs. 73.2 %), and farrowing rate (71.8 % vs. 73.2 %) were observed between the CONTROL and SLC groups, respectively (P > 0.05). Nevertheless, the total number of piglets born per litter in the SLC group was higher than in the CONTROL group (14.6 ± 0.9 vs. 12.3 ± 0.6, respectively, P = 0.049). Interestingly, the prevalence of stillbirth in the SLC group was lower than in the CONTROL group (6.2 % vs. 11.6 %, respectively, P < 0.001). Moreover, the newborn piglets in the SLC group exhibited higher birth weight and BMI compared to those in the CONTROL group (1.36 ± 0.03 vs. 1.26 ± 0.02 kg, P = 0.005, and 18.3 ± 0.3 vs. 17.3 ± 0.2 kg/m 2 , P = 0.003). In conclusion, employing sperm doses after SLC through a low density colloid in artificial insemination within a commercial breeding operation did not have a detrimental impact on either fertility or fecundity traits but showed potential benefits in increasing the total number of piglets born per litter. Moreover, improvements were observed in the birth weight and body indexes of piglets, and the percentage of stillbirths was reduced. Our findings introduce new possibilities for antibiotic alternatives in semen extenders to reduce the risk of antimicrobial resistance in the swine industry. Additionally, they provide compelling reproductive outcomes supporting the integration of SLC-prepared semen doses into artificial insemination practices., (Copyright © 2024 Elsevier Inc. All rights reserved.)

There are few existing publications that describe transvaginal ultrasound-guided Ovum Pick-Up (OPU) in sows, and the impacts of the procedure for the welfare of the animals are unknown. In this study, we evaluated the effects of OPU, performed following restraint in a claw-trimming chute, on the animal welfare and reproductive health of second parity hybrid sows. The study utilized a generalized randomized block design at a commercial sow pool. We assessed salivary cortisol levels before, during, and after the procedure to compare the physiological stress response between OPU and restraint chute procedures (control group). We found a significant increase in salivary cortisol caused by the physical restraint procedure, and that the salivary cortisol level at the end of the procedure did not differ between OPU and control groups (p = 0.51). Furthermore, we conducted a novel approach-aversion test for sows, designed to assess if a feed reward would motivate the animals to willingly participate in the OPU-procedure. The animals were trained daily to enter the chute to access a feed reward. Ten animals in each group failed to complete the training period and did not voluntarily enter the restraint chute on the experimental day. This indicates that even the short daily restraint procedure during the four-day long training period was aversive to some animals. There was no difference in aversion towards the restraint chute between OPU and control groups one day after the procedure. The reproductive performance of the animals was subsequently evaluated through oestrus synchronization and insemination of the sows after the experiment. There was no observed difference in the farrowing rate (p = 0.72) and total number of born piglets (p = 0.84) between OPU and control sows. On average, we retrieved 9.0 ± 5.9 oocytes during the OPU-sessions (N = 26). Our results show that a majority of the sows prioritize the motivation for feed over their aversion to the OPU procedure. However, the physical restraint procedure is unpleasant for the animals and elicits a temporary stress response. We suggest that transvaginal OPU may be used for the recovery of oocytes from live sows, but refinements are needed to avoid stress during the lifting procedure. Such modifications could also potentially reduce the observed inter-individual variations in oocyte recovery outcomes., Competing Interests: Declaration of competing interest The authors declare no conflicting interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Melatonin, a hormone synthesized in various tissues, plays a crucial role in modulating sperm characteristics, yet its protective function on boar sperm remains poorly understood. This study aimed to investigate the expression and localization of melatonin-related proteins (AANAT, ASMT, MT1, MT2, and NQO2) in pig tissues, assess the impact of melatonin on pig sperm motility parameters and quality, and elucidate the underlying molecular mechanisms. Our results revealed widespread expression of AANAT, ASMT, MT1, MT2, and NQO2 proteins in pig tissues, particularly in the testis. Specific localization patterns were observed in Leydig cells, reproductive epithelium, and columnar epithelium cells in the testis and cauda epididymis. Additionally, melatonin membrane receptors MT1 and MT2 were detected in boar sperm. Melatonin treatment significantly enhanced boar sperm motility parameters and quality, particularly with 10 nM melatonin treatment. Inhibition of the MT1 receptor, but not the MT2 receptor, resulted in decreased sperm motility, highlighting the pivotal role of the MT1 receptor in mediating melatonin's effects on boar sperm. Metabolomic analysis revealed significant alterations in sperm metabolites following melatonin supplementation, particularly in amino acid metabolism. Overall, our findings provide comprehensive insights into melatonin's mechanisms in improving boar sperm quality, suggesting its potential as a therapeutic agent for enhancing male fertility., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Decreased oocyte quality is a significant contributor to the decline in female fertility that accompanies aging in mammals. Oocytes rely on mRNA stores to support their survival and integrity during the protracted period of transcriptional dormancy as they await ovulation. However, the changes in mRNA levels and interactions that occur during porcine oocyte maturation and aging remain unclear. In this study, the mRNA expression profiles of porcine oocytes during the GV, MII, and aging (24 h after the MII stage) stages were explored by transcriptome sequencing to identify the key genes and pathways that affect oocyte maturation and postovulatory aging. The results showed that 10,929 genes were coexpressed in porcine oocytes during the GV stage, MII stage, and aging stage. In addition, 3037 genes were expressed only in the GV stage, 535 genes were expressed only in the MII stage, and 120 genes were expressed only in the aging stage. The correlation index between the GV and MII stages (0.535) was markedly lower than that between the MII and aging stages (0.942). A total of 3237 genes, which included 1408 upregulated and 1829 downregulated genes, were differentially expressed during porcine oocyte postovulatory aging (aging stage vs. MII stage). Key functional genes, including ATP2A1, ATP2A3, ATP2B2, NDUFS1, NDUFA2, NDUFAF3, SREBF1, CYP11A1, CYP3A29, GPx4, CCP110, STMN1, SPC25, Sirt2, SYCP3, Fascin1/2, PFN1, Cofilin, Tmod3, FLNA, LRKK2, CHEK1/2, DDB1/2, DDIT4L, and TONSL, and key molecular pathways, such as the calcium signaling pathway, MAPK signaling pathway, TGF-β signaling pathway, PI3K/Akt signaling pathway, FoxO signaling pathway, gap junctions, and thermogenesis, were found in abundance during porcine postovulatory aging. These genes are mainly involved in the regulation of many biological processes, such as oxidative stress, calcium homeostasis, mitochondrial function, and lipid peroxidation, during porcine oocyte postovulatory aging. These results contribute to a more in-depth understanding of the biological changes, key regulatory genes and related biological pathways that are involved in oocyte aging and provide a theoretical basis for improving the efficiency of porcine embryo production in vitro and in vivo., Competing Interests: Declaration of competing interest None., (Copyright © 2024. Published by Elsevier Inc.)

Objective: To evaluate the agreement between measurements of invasive blood pressure (IBP) and oscillometric blood pressure from the tongue (OBPton) using a multiparameter monitor., Study Design: Unblinded, prospective, experimental study., Animals: A total of 12 female Large White crossbreed pigs., Methods: Pigs undergoing experimental procedures that required arterial cannula placement were recruited. A blood pressure cuff with the closest width to 40% of the circumference of the tongue was placed rostral to the lingual frenulum. Systolic, mean and diastolic IBP and OBPton were measured simultaneously at 5 minute intervals. Agreement between paired measurements was examined using Bland-Altman analysis. Mean bias, precision (standard deviation of mean bias), 95% limits of agreement, correlation coefficients and percentage of measurements within 10 and 20 mmHg of IBP were calculated., Results: The total numbers of paired measurements recorded were 124, 126 and 124 for systolic, mean and diastolic blood pressures, respectively. The mean bias, precision and 95% limits of agreement for systolic OBPton were 11.5, 11.5 (-11.1 to 34.2), for mean OBPton 5.6, 5.7 (-5.7 to 16.8) and for diastolic OBPton 7.6, 10.1 (-12.1 to 27.4) mmHg. Correlation coefficients were greater than 0.9 for mean OBPton only. More than 50% of measurements were within 10 mmHg of IBP and 80% of measurements were within 20 mmHg of IBP for mean and diastolic OBPton only., Conclusions and Clinical Relevance: The tongue as a cuff site for oscillometric blood pressure measurement is a useful site for measuring mean arterial, but not systolic or diastolic blood pressure in anaesthetized Large White crossbreed pigs. This technique fulfils the American College of Veterinary Internal Medicine criteria for measuring mean arterial pressure but not systolic or diastolic arterial pressure., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Skeleton bones, distinguished by trabecular and cortical bone tissue content, exhibit varied growth and composition, in response to modified dietary calcium and phosphorus levels. The study investigated how gilts adapt their individual bone and bone region mineralisation kinetics in response to changing intake of Ca and P. A total of 24 gilts were fed according to a two-phase (Depletion (D) 60-95 and Repletion (R) 95-140 kg BW, respectively). During the D phase, gilts were fed either 60% (D60) or 100% (D100) of the estimated P requirement. Subsequently, during the R phase, half of the gilts from each D diet were fed either 100% (R100) or 160% (R160) of the estimated P requirement according to a 2 × 2 factorial arrangement. Bone mineral content (BMC) was assessed in the whole body, individual bones (femur and lumbar spine L2-L4), and bone regions (head, front legs, trunk, pelvis, femur, and hind legs) every 2 weeks using dual-energy X-ray absorptiometry (DXA). At 95 kg BW, gilts fed D60 showed reduced BMC and BMC/BW ratio in all studied sites compared to those fed D100 (P < 0.001). During the depletion phase, the allometric BW-dependent regressions slopes for BMC of D100 gilts remained close to 1 for all sites and did not differ from each other. In contrast, the slopes were lower in D60 gilts (P < 0.05), with an 18% reduction in the whole body, except for the front and hind legs, femur, and pelvis, which exhibited higher reductions (P < 0.05). At 140 kg BW, BMC and BMC/BW ratio of all studied sites were similar in gilts previously fed D60 and D100, but higher in R160 than in R100 gilts (P < 0.05), except for front and hind legs. During the repletion phase, the allometric BW dependent regressions slopes for BMC were lower (P < 0.05) in R100 than in R160 gilts (for whole body -10%; P < 0.01) except for front and hind legs, femur, and pelvis. In conclusion, bone demineralisation and recovery followed similar trends for all measured body sites. However, the lumbar spine region was most sensitive whereas the hind legs were least sensitive. These data suggest that using bone regions such as the head and forelegs that can be collected easily at the slaughterhouse may be a viable alternative to whole body DXA measurement., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Alternative farrowing systems that have been developed in recent years could have a positive effect on the welfare of sows during farrowing and lactation. Oxytocin measurements in saliva may provide information about positive animal welfare status. The purpose of this study was to evaluate the changes in salivary oxytocin concentrations in sows during the lactation period in three different farrowing systems and in two different seasons. Crossbred Duroc sows (n = 34, average parity = 3.6 ± 1.80) were housed in conventional farrowing crates (FC) (n = 10) or in farrowing pens with temporary crating (TC), including SWAP (n = 12) and JFL15 (n = 12) in two different seasons: summer and winter. Saliva samples were collected for six days during lactation: days 2, 4, 12, 23, 25 (i.e., 1-day post-weaning) and 26 (i.e., 2-day post-weaning) after farrowing. Moreover, behavioral data from sows was recorded on days 2, 4, 12 and 23 after farrowing, using a 30-s scan sampling method for 3 min per pen to record the behaviors which were assessed by the same observer. The results showed that the salivary oxytocin concentrations were 472.5 pg/mL and 399.4 pg/mL higher in both TC (SWAP and JLF15, respectively) than in the FC in early-lactation period, and these differences were more pronounced in summer and at the end of lactation in winter. In terms of behavior, higher number of mother-young interactions were observed in TC than FC in early- and mid-lactation period. In conclusion, TC is associated to a higher salivary oxytocin concentration that could indicated an increased mother-young interaction, although oxytocin concentration can be influenced by other factors, such as season or day of lactation., Competing Interests: Declaration of competing interest None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024. Published by Elsevier Ltd.)

This study assessed the effects of dexamethasone treatment on farrowing performance and piglet traits in the first 5 days of life in multiparous sows, a high-risk group for stillbirths and prolonged farrowing. In this study, 185 multiparous sows (parity 4.25 ± 0.14) were selected on the day of farrowing and divided into three treatments: CON - control, without dexamethasone treatment; DexaPF - treatment with dexamethasone (20 mg im per female) at the time of copious colostrum secretion (pre-farrowing); and DexaFO - treatment with dexamethasone (20 mg im per female) when the first piglet was born (farrowing onset). All sows and their litters were monitored for farrowing duration, obstetric interventions, colostrum yield and intake, newborn piglet traits, and piglet performance until 5 d of age. A subsample of 106 females (∼35 per treatment) had their blood glucose concentration checked hourly shortly after the first piglet was born until the end of farrowing. Additionally, blood samples from 42 litters were collected for immunocrit evaluation. The results showed no differences regarding farrowing duration (CON = 258.02 ± 13.81 min; DexaPF = 251.29 ± 13.60 min; DexaFO = 294.92 ± 13.89 min; P = 0.06) and obstetric intervention rates among treatments (CON = 36.58 ± 6.78 %; DexaPF = 42.16 ± 6.89 %; DexaFO = 48.05 ± 7.08 %; P = 0.45). The blood glucose concentration during farrowing was higher in DexaPF (94.56 ± 1.57 mg/dL; P < 0.001) than in CON (73.50 ± 1.72 mg/dL) and DexaFO (87.94 ± 1.80 mg/dL). No differences were observed regarding total piglets born and born alive, stillborn, newborn piglet vitality, colostrum intake, immunocrit, colostrum yield, and glycemia and rectal temperature at 24 h of age (P ≥ 0.13). Regarding meconium staining, higher percentages of piglets born without meconium staining were observed in DexaFO (54.77 ± 5.21 %; P = 0.02) compared with CON (48.58 ± 5.26 %), and no difference was observed for the DexaPF group (53.23 ± 5.21 %). In addition, a higher unbroken umbilical cord rate was observed in DexaFO (92.41 ± 1.31 %; P < 0.01) than the CON or DexaPF (86.91 ± 1.97 % and 89.31 ± 1.67 %, respectively). However, the treatments did not affect piglet performance (weight gain and survival) until 5 d of age (P ≥ 0.15). In summary, dexamethasone treatment in periparturient multiparous sows did not improve farrowing performance and key production parameters, such as the piglet weight gain and survival up to 5 d of age., Competing Interests: Declaration of competing interest No conflicts of interest to declare. The funding sponsors had no role in the design of the study, the collection, analysis, and interpretation of data, the writing of the manuscript, and the decision to publish the results., (Copyright © 2024 Elsevier Inc. All rights reserved.)

International interest in loose-housed farrowing is growing and there are ongoing discussions within the European Union (EU) on new legal requirements. However, there is a lack of empirical data on loose-housed farrowing pen sizes and sow dimensions in commercial production. The aim of this study was to map and describe sow size and loose-housing farrowing pen size on commercial piglet-producing farms in Sweden. The study included 146 sows and 51 pen types on 35 medium sized to large Swedish piglet-producing farms (ranging from 106 to 1300 sows in production). Sow length ranged from 129 to 238 cm (mean ± SD 191.3 ± 19.3 cm) and sow height from 74 to 133 cm (86.7 ± 7.7 cm). Floor space occupied by the sow when lying down (length x height) ranged from 1.0 to 3.2 m 2 (1.7 ± 0.3 m 2 ). Pen length ranged from 259 to 415 cm (315.1 ± 24.3 cm), pen width from 188 to 245 cm (207.0 ± 10.7 cm), total pen area from 5.7 to 8.9 m 2 (6.5 ± 0.5 m 2 ), piglet corner area from 0.5 to 1.8 m 2 (1.1 ± 0.4 m 2 ) and area available for the sow (total area - piglet corner area) from 3.9 to 6.4 m 2 (5.4 ± 0.6 m 2 ). These results show that there is substantial variation in sow, pen and piglet corner size on commercial piglet-producing farms in Sweden. This poses a risk of mismatches between sow and pen size (pens too short in relation to sow dimensions), especially for older sows. These findings are of practical significance for animal welfare and production and emphasise the importance of designing loose-housed pens adapted to future sow, litter and piglet size., (© 2024. The Author(s).)

This study evaluated the efficiency of prostaglandin F2α (PGF) to hasten ovulation in weaned sows. In experiment I, weaned sows detected in estrus (0 h) received: no hormone (Control; n = 56); 0.5 mg PGF IM at 0 h and 2 h (PGF0; n = 56); or 0.5 mg PGF IM at 24 h and 26 h (PGF24; n = 55). In experiment II, weaned sows that did not express estrus signs until 72 h after weaning (0 h) were assigned to: no hormone (Control; n = 45); 10 µg buserelin acetate IM at 0 h (Buserelin; n = 43); 0.5 mg PGF IM at 34 h and 36 h (PGF; n = 44); or 10 µg buserelin acetate IM at 0 h plus 0.5 mg PGF IM at 34 h and 36 h (Buserelin + PGF; n = 45). In experiment I, no effect of PGF on the interval treatment onset to ovulation was observed (P > 0.05), and no treatment effect was observed on the relative or cumulative proportion of females that ovulated post-treatment onset (P > 0.05). In experiment II, treatment onset to ovulation interval was shorter for Buserelin group than for PGF group (P < 0.05), and a higher cumulative percentage of Buserelin treated sows ovulated up to 48 h compared to PGF and Control groups (P < 0.01), with no differences from Buserelin + PGF. Treatments did not affect total number of piglets born in both experiments (P > 0.05). In conclusion, PGF did not hasten ovulation timing or affect litter size in weaned sows., Competing Interests: Declaration of competing interest The authors have no conflict of interest to declare., (Published by Elsevier Inc.)

Since 2022, European specifications for organic pig farming have evolved to distribute 100 % organic feed and to reinforce the link to the soil with feed resources that should primarily be obtained from the farm or the same region. Feeding strategy acts as a lever to improve various quality dimensions of organic (as well as conventional) pork, including intrinsic dimensions (carcass composition, nutritional, organoleptic, technological, sanitary qualities) and extrinsic dimensions related to animal farming (image). Diet may also influence the risk of undesirable odours or flavours that may be found in pork from non-castrated male pigs. This study aimed at evaluating the effects of a specific feeding strategy on several quality dimensions of organic meat from non-castrated male pigs. The experiment was conducted with 77 organic non-castrated male pigs (Piétrain NN × Large White) reared according to organic specifications and distributed in two batches. Within litters, male littermates were allocated at around 33 kg of live weight to either a Control group which received a Control feed (C) corresponding to the organic specifications or in a Bio+ group which received an organic test feed based mainly on French raw materials and which contained more fibres (faba bean and access to forages) and omega-3 fatty acids (linseed, camelina). All pigs were reared in the same building on deep straw bedding (1.3 m 2 /pig) with free outdoor access (1.0 m 2 /pig) using one pen per experimental group. Pigs were fed ad libitum until slaughter at about 125 kg live weight. Average daily gain, carcass weight and lean meat content did not differ significantly between C and Bio+ pigs. Compared to C, Bio+ pigs had higher (P < 0.05) ultimate pH in the loin (Longissimus muscle) and ham (Gluteus medius, and Semimembranosus) muscles, associated with a lower Longissimus muscle glycolytic potential (P < 0.001). Loin and ham meat from Bio+ vs. C pigs was lighter (P < 0.05) and had a more intense red colour (P < 0.10). The Bio+ strategy led to a lower Longissimus muscle n-6:n-3 fatty acid ratio (P < 0.001), indicating an improvement in pork nutritional value. Backfat skatole concentration was lower in Bio+ than in C pigs whereas backfat androstenone was higher in Bio+ than in C pigs (P < 0.05). Altogether, we demonstrated that the Bio+ strategy had positive impacts on several qualities of organic pork from non-castrated male pigs., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Reducing the dietary crude protein (CP) could effectively reduce pressure on protein ingredient supplies. However, few data have been reported about the extent to which CP can be reduced and whether limiting the use of soybean meal leads to electrolyte imbalance. In this experiment, using the low protein (LP) diet [2% lower than NRC (2012)], seventy-two piglets (35 days old) were randomly divided into 2 groups with 6 replicates of 6 piglets each: CON group (CP = 18.5%) and LP group (CP = 16.5%), to investigate the effect of the LP diet on electrolyte balance, acid-base balance, intestinal structure and amino acid transport in piglets. The results revealed that the LP diet decreased the average daily gain and dietary CP digestibility, and damaged the villi structure of the small intestine. Compared with the CON diet, the potassium content decreased and the chlorine content increased in the LP diet, and similar trends were shown in piglet serum. The arterial pH, pCO 2 , HCO 3 - , and base excess of piglets in the LP group were lower than those in the CON group, while pO 2 was higher than those in the CON group. Interestingly, the LP diet significantly increased the lysine content in piglet serum and significantly decreased the levels of arginine, leucine, and glutamic acid. Furthermore, the LP diet significantly affected the expression of some amino acid transport vectors (B 0 AT1, EAAC1, and y + LAT1). In summary, these findings suggested that the LP diet leads to acid-base imbalance, amino acid transport disorder and amino acids imbalance in piglets, and the dietary electrolyte may be a key factor in the impact of the LP diet on piglet growth performance and intestinal health., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

The utilization of dietary components to support gut function and the health of young animals is an important factor for improved performance. The influence of high dietary fat levels in a low or high energy density diet on the performance of weaned piglets in relation to intestinal absorptive function, amino acid utilization, oxidative stress, and microbial metabolites was assessed in this study. The study examined the effect of two different diets containing either a low energy density/high-fat level or a high energy density/high-fat level. A total of 16 healthy weaners (9.60 ± 0.13 kg) were allocated to one of the two dietary treatments. There were eight weaners per treatment. Results showed that feed intake and body weight gain of weaners were increased by the diet of high energy density/high-fat level (p < 0.05), but the feed efficiency showed an increased tendency of significance (p = 0.05). In the duodenum, the villus height (VH) and VH/crypt depth (CD) ratio (VH:CD) were increased by dietary high energy density/high fat. In the jejunum and ileum, the CD was increased by low energy density/high-fat diet, while the goblet cell count and VH:CD were increased by dietary high energy density/high-fat level. Methionine, lysine and phenylalanine concentrations were increased by high energy density/high-fat diet while low energy density/high-fat diet showed an increased tendency to increase citrulline and ornithine concentrations in the piglet. Oxidative stress marker, lactase enzyme activity and serum calcium concentration were increased by a high energy density/high-fat diet. Increased dietary fat in all diets induced diarrhoea in the weaners (p < 0.01). It was concluded that a dietary high energy density/high-fat diet seems to positively modulate gut absorptive function, serum amino acid (methionine and lysine), calcium levels and increased oxidative stress markers in the weaned piglets., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

The present case series evaluated the potential benefits of a flapless approach in the regenerative treatment of residual deep intrabony defects. In each of 11 patients, one periodontal defect with an intrabony component of ≥ 3 mm was treated regeneratively using enamel matrix derivative combined with a closed surgical technique. Clinical and radiographic parameters were recorded at baseline and at 12 and 24 months postoperatively. All defects experienced favorable clinical and radiographic outcomes at the 24-month follow-up. When considering only sites located in the anterior region, all experienced complete pocket closure. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate how the cumulative expulsion interval, litter size, and birth order influence the characteristics of newborn piglets from hyperprolific sows, as well as their intake of colostrum. Analysis was conducted on the temporal aspects of parturition in 254 sows, including 3920 piglets. Newborn piglet characteristics examined encompassed delivery time, birth order, birth status, umbilical cord rupture, meconium staining, delivery ease, birth weight, blood oxygen saturation, and heart rate. From the raw data, colostrum intake, birth interval, and cumulative birth interval of each piglet were computed. Piglets were sorted based on the cumulative expulsion interval into nine categories: 0-30, 31-60, 61-90, 91-120, 121-150, 151-180, 181-210, 211-240, and >240 min. Litter sizes were categorized into three groups: 10-13, 14-17, and ≥18 piglets per litter. The birth-order ranking referred to the piglet's position within a litter and was categorized into four quartiles: 1, 2, 3, and 4. On average, the expulsion interval, cumulative expulsion interval, and colostrum consumption were 14.8 ± 21.8 min, 138.6 ± 155.7 min, and 407.6 ± 162.1 g, respectively. In litters with ≥18 piglets, the percentage of piglets with inadequate colostrum intake (<300 g) was higher compared to litters with 10-13 piglets (33.1 % vs. 12.9 %, P < 0.001) and 14-17 piglets (23.9 %, P < 0.001). The occurrence of stillbirths in the fourth quartile of the litter was higher than in the first (16.0 % vs. 2.2 %, P < 0.001), second (4.0 %, P < 0.001), and third (7.8 %, P < 0.001) quartiles. Among litters with ≥18 piglets, those born in the third quartile exhibited lower colostrum consumption compared to those born in the first quartile (346.0 ± 9.9 vs. 391.4 ± 8.6 g, P = 0.028). Colostrum intake decreased with longer cumulative expulsion intervals, evident from a notable decline starting at 90 min post-farrowing compared to piglets born within the first 30 min (P = 0.004). Interestingly, colostrum consumption exhibited a negative correlation with the cumulative expulsion interval (P < 0.001), but not with individual piglet expulsion intervals (P = 0.460). Piglets born with meconium staining were most prevalent among those with a cumulative expulsion interval of >240 min. In summary, both the cumulative expulsion interval and birth-order ranking significantly impact the physiological characteristics of newborn piglets and their colostrum intake. Colostrum consumption decreases and newborn piglet characteristics change with higher cumulative expulsion intervals. Identifying piglets at high risk of hypoxia and implementing appropriate treatments and management strategies within an optimal timeframe could aid pig producers in reducing pre-weaning mortality among piglets born to hyperprolific sows., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Longitudinal records of automatically-recorded vaginal temperature (T V ) could be a key source of data for deriving novel indicators of climatic resilience (CR) for breeding more resilient pigs, especially during lactation when sows are at an increased risk of suffering from heat stress (HS). Therefore, we derived 15 CR indicators based on the variability in T V in lactating sows and estimated their genetic parameters. We also investigated their genetic relationship with sows' key reproductive traits., Results: The heritability estimates of the CR traits ranged from 0.000 ± 0.000 for slope for decreased rate of T V (Slope De ) to 0.291 ± 0.047 for sum of T V values below the HS threshold (HSU B ). Moderate to high genetic correlations (from 0.508 ± 0.056 to 0.998 ± 0.137) and Spearman rank correlations (from 0.431 to 1.000) between genomic estimated breeding values (GEBV) were observed for five CR indicators, i.e. HS duration (HSD), the normalized median multiplied by normalized variance (Nor&#95;medvar), the highest T V value of each measurement day for each individual (Max Tv ), and the sum of the T V values above (HSU A ) and below (HSU B ) the HS threshold. These five CR indicators were lowly to moderately genetically correlated with shoulder skin surface temperature (from 0.139 ± 0.008 to 0.478 ± 0.048) and respiration rate (from 0.079 ± 0.011 to 0.502 ± 0.098). The genetic correlations between these five selected CR indicators and sow reproductive performance traits ranged from - 0.733 to - 0.175 for total number of piglets born alive, from - 0.733 to - 0.175 for total number of piglets born, and from - 0.434 to - 0.169 for number of pigs weaned. The individuals with the highest GEBV (most climate-sensitive) had higher mean skin surface temperature, respiration rate (RR), panting score (PS), and hair density, but had lower mean body condition scores compared to those with the lowest GEBV (most climate-resilient)., Conclusions: Most of the CR indicators evaluated are heritable with substantial additive genetic variance. Five of them, i.e. HSD, Max Tv , HSU A , HSU B , and Nor&#95;medvar share similar underlying genetic mechanisms. In addition, individuals with higher CR indicators are more likely to exhibit better HS-related physiological responses, higher body condition scores, and improved reproductive performance under hot conditions. These findings highlight the potential benefits of genetically selecting more heat-tolerant individuals based on CR indicators., (© 2024. The Author(s).)

Fibres, as abundant in agricultural by-products, exhibit a large range of physicochemical properties that can influence digestive processes such as digesta mean retention time (MRT), thereby affecting nutrient digestion kinetics. In this study, we investigated the effects of particle size of insoluble fibres, and gelation of soluble fibres on MRT of liquids, fine solids, and fibrous particles in the different segments of the gastrointestinal tract (GIT) of pigs. Twenty-four boars (51.6 ± 4.90 kg) were allocated to four diets; two diets contained 15% wheat straw, either coarsely chopped or finely ground (1-mm screen), two diets contained 27% wheat bran without or with the addition of 10% low-methylated pectin. After 14 days of adaptation to the diet, a total collection of faeces was performed to determine the total tract digestibility of nutrients. Thereafter, pigs were fed diets supplemented with tracers for at least 5 days and dissected following a frequent feeding procedure to approach steady-state passage of digesta. The MRT of liquids (Co-EDTA), fine solids (TiO 2 ), and fibrous particles (Chromium-mordanted fibres) in the different segments of the GIT were quantified. In the stomach, particle size reduction of straw decreased the MRT of fine solids by 02:39 h, and fibrous particles by 07:21 h (P < 0.10). Pectin addition to the wheat bran diet reduced the MRT of fine solids by 03:09 h, and fibrous particles by 07:10 h (P < 0.10), but not of liquids, resulting in less separation between digesta phases in the stomach compared with the bran diet (P < 0.05). In the mid-small intestine (SI), pectin addition reduced the MRT of fibrous particles and the separation between fibrous particles and fine solids. No further effects of particle size reduction of straw nor pectin addition on MRT and digestibility of starch, nitrogen, or fat were observed in the SI. In the large intestine (LI), particle size reduction of straw reduced separation between fibrous particles and fine solids (P < 0.10), while pectin addition had no effects. Total tract, non-starch polysaccharide degradation of straw was poor (∼31%), and unaffected by particle size reduction (P > 0.10). The complete fermentation of pectin did not influence the degradation of wheat bran fibres (∼51%). In conclusion, the effects of particle size of insoluble fibres and gelling properties of soluble fibres on the passage of digesta phases were most pronounced in the stomach, but less prominent in distal segments of the GIT., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Some of the biggest changes in mineral nutrition for pigs that have occurred due to recent research were caused by the understanding that there is a loss of endogenous Ca and P into the intestinal tract of pigs. This resulted in development of the concept of formulating diets based on standardized total tract digestibility (STTD) rather than apparent total tract digestibility because the values for STTD of these minerals are additive in mixed diets. There are, however, no recent summaries of research on digestibility and requirements of macro- and microminerals and vitamin D for pigs. Therefore, the objective of this review was to summarize selected results of research conducted over the last few decades to determine the digestibility and requirements of some minerals and vitamin D fed to sows and growing pigs. Benefits of microbial phytase in terms of increasing the digestibility of most minerals have been demonstrated. Negative effects on the growth performance of pigs of over-feeding Ca have also been demonstrated, and frequent analysis of Ca in complete diets and raw materials is, therefore, recommended. There is no evidence that current requirements for vitamin D for weanling or growing-finishing pigs are not accurate, but it is possible that gestating and lactating sows need more vitamin D than currently recommended. Vitamin D analogs and metabolites such as 1(OH)D 3 and 25(OH)D 3 have beneficial effects when added to diets for sows in combination with vitamin D 3 . Recent research on requirements for macrominerals other than Ca and P is scarce, but it is possible that Mg in diets containing low levels of soybean meal is marginal. Some of the chelated microminerals have increased digestibility compared with sulfate forms, and hydroxylated forms of Cu and Zn appear to be superior to sulfate or oxide forms. Likewise, dicopper oxide and Cu methionine hydroxy analog have a greater positive effect on the growth performance of growing pigs than copper sulfate. The requirement for Mn may need to be increased whereas there appears to be no benefits of providing Fe above current requirements. In conclusion, diets for pigs should be formulated based on values for STTD of Ca and P and there are negative effects of providing excess Ca in diets. It is possible vitamin D analogs and metabolites offer benefits over vitamin D 3 in diets for sows. Likewise, chelated forms of microminerals or chemical forms of minerals other than sulfates or oxides may result in improved pig performance., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

As climate change intensifies, heat stress mitigation for pigs becomes more important. Trials involving induced heat waves are useful to test several measures (e.g. reduced stocking density) at a faster rate, but only when accurately evaluated and validated. In the present study, we investigated the suitability of an artificial heating protocol at different pig weights (experiment 1). The impact of different stocking densities on fattening pigs during an artificial heat wave (experiment 2) was also investigated. Experiment 1: Forty 20-week-old pigs weighing 96.5 ± 7.3 kg (W 100 ) and forty 17-week-old pigs weighing 72.7 ± 9.9 kg (W 70 ) were housed in two compartments. An artificial heat wave (heat load) was induced for 3 days. During 3-day periods before, during and after the heat load, physiological parameters (respiration rate (RR), rectal temperature (T rectal ), skin temperature (T skin ) and behavior) were measured and average daily feed intake was observed. Ambient temperature, relative humidity and temperature-humidity index (THI) were monitored. Experiment 2: A total of 150 fattening pigs were randomly divided into three treatment groups: SD 1.3 (1.3 m 2 /pig), SD 1.0 (1.0 m 2 /pig) and SD 0.8 (0.8 m 2 /pig). All pens had a total pen surface of 4.88 m 2 , corresponding with 4, 5 and 6 fattening pigs in the SD 1.3 , SD 1.0 and SD 0.8 groups, respectively. The heat load was induced for 7 days on week 21. Respiration rate and T rectal were observed as in experiment 1. Average daily gain and average daily feed intake were also noted. During the heat load, THI reached ≥ 75 (78.4 (experiment 1) and 78.6 (experiment 2)), even when relative humidity decreased to ± 45%. Every physiological parameter showed significant increases during the heat load. The prolonged heating protocol in experiment 2 also provoked significant decreases in average daily feed intake (15%) and average daily gain (19%) for all groups. Weight within the studied range of 70-100 kg did not have a significant impact on any of the parameters. However, T skin was affected by both weight and heat load (P < 0.05), where T skin from W 100 was always lower in comparison to W 70 . In addition, we found that 0.8 m 2 /pig doubled the increase of T rectal during the heat load, namely SD 0.8 (0.22 °C) compared to SD 1.0 (0.12 °C) (P = 0.033) and SD 1.3 (0.13 °C) (P = 0.053). This suggests that pigs housed at higher densities are less able to regulate their internal heat production. However, RR and performances were not significantly affected by heat load in this experimental set-up. A stocking density of 1.0 m 2 /animal may be sufficient to mitigate some negative effects of heat stress., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Pigs in production systems are routinely exposed to challenging situations including abrupt weaning, painful husbandry procedures, intense contact with stockpeople, and exposure to novel social and physical environments. The resilience of pigs to these stressors has implications for animal welfare and productivity and can be affected by early life experiences. In rodents and primates, early experiences with stressors that the animal can adequately cope with confers future stress adaptability, leading to less abnormal behaviour, lower behavioural and physiological responses to stressors, and faster recovery after stress exposure. Early experiences that can affect the ability of pigs to overcome challenge include interactions with the dam, conspecifics, humans, and the overall complexity of the environment. Farrowing crates limit the sow's ability to show maternal behaviour towards piglets, and negatively affect piglet social behaviour during lactation, with less play and more manipulation of pen mates in crates than in large pens. Rearing in pens has been proposed to improve the ability of pigs to cope with routine stressors, but the evidence for this is conflicting. The early housing environment can affect general fearfulness and fear of humans, and surprisingly, most studies have shown fear responses to be greater in pigs reared pens than in crates. Given the potential for fear to affect animal welfare and productivity, more detailed research on early housing effects is needed. While there is limited evidence that early housing influences fear in the longer term, human contact early in life appears to have a more profound and sustained effect, with regular positive human interaction early in life having an enduring effect on reducing pigs' fear of humans. The practicality of positive human-pig interaction in a commercial environment needs to be examined further, but only a small amount of positive human contact early in life can improve the resilience of pigs to routine husbandry stressors. Early social experience with non-littermates reduces stress at weaning and mixing, while early weaning before 3-4 weeks of age increases abnormal behaviours. Environmental enrichment, such as foraging substrates and increased floor space, reduces abnormal behaviour in piglets, but housing in an enriched environment early in life and subsequently in a non-enriched environment can increase abnormal behaviour if these environments are dramatically different. Although the later environment can modify the influence of the early environment, overall, early life experiences can be important in shaping how pigs cope with stress in both an immediate and longer-term capacity., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The feeding behaviour of individual growing-finishing pigs can be continuously monitored using sensors such as electronic feeding stations (EFSs), and this could be further used to monitor pig welfare. To make accurate conclusions about individual pig welfare, however, it is important to know whether deviations in feeding behaviour in response to welfare issues are shown only on average or by each individual pig. Therefore, this study aimed (1) to quantify the individual variation in feeding behaviour changes in response to a range of welfare issues, and (2) to explain this individual variation by quantifying the responses to welfare issues for specific subgroups of pigs. We monitored four rounds of 110 growing-finishing pigs each (3-4 months per round). We collected feeding behaviour data using IVOG® EFSs and identified health issues and heat stress using climate sensors and twice-weekly health observations. For each pig, a generalised additive model was fitted, which modelled feeding behaviour through time and estimated the effect of each welfare issue that the pig had suffered from. The range of these effect estimates was compared between pigs to study the individual variation in responses. Subsequently, pigs were repeatedly grouped using physical and feeding characteristics, and, with meta-subset analysis, it was determined for each group whether a deviation in response to the welfare issue (i.e. their combined effect estimates) was present. We found that the range in effect estimates was very large, approaching normal distributions for most combinations of welfare issues and feeding variables. This indicates that most pigs did not show feeding behaviour deviations during the welfare issue, while those that did could show both increases and reductions. One exception was heat stress, for which almost all pigs showed reductions in their feed intake, feeding duration and feeding frequency. When looking at subgroups of pigs, it was seen that especially for lameness and tail damage pigs with certain physical characteristics or feeding strategies did consistently deviate on some feeding components during welfare issues (e.g. only relatively heavier pigs reduced their feeding frequency during lameness). In conclusion, while detection of individual pigs suffering from heat stress using feeding variables should be feasible, detection of (mild) health issues would be difficult due to pigs responding differently, if at all, to a given health issue. For some pigs with specific physical or behavioural characteristics, nevertheless, detection of some health issues, such as lameness or tail damage, may be possible., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Farrowing crates are widely used as the main housing system for farrowing and lactating sows on commercial farms although they have a negative impact on sow welfare and behaviour. One of the main reasons for using farrowing crates is to reduce piglet mortality during farrowing and lactation. We compared the effects of temporary crating (TC) versus free farrowing (FF) with different nest-building materials on production and welfare measures. Sows were investigated using a 2 × 3 factorial design. Sows were allocated to two farrowing treatments: FF sows were not crated around farrowing, and TC sows were crated from 2 days before expected farrowing until 3 days after farrowing, when the crate was opened. In both farrowing treatments, the nest-building material was given from 7 days prior to farrowing as follows: (1) 1 L of straw twice per day, (2) 1 sheet of newspaper twice per day or (3) fastened jute fabric to the farrowing crate. The study consisted of two parts; part 1 included a total of 87 sows for data on piglet mortality and growth, and part 2 included data on nest-building and farrowing behaviour from a subset of these sows (n = 34). Farrowing treatment affected piglet mortality; FF sows had a lower number of stillborn piglets than TC sows (P = 0.04), but the number of crushed piglets was higher (P < 0.01). Nest-building material tended to have an impact on total number of crushed piglets (P = 0.08) and piglets that died during 3 days of lactation (P = 0.09). Litter growth was better in the FF group than in the TC group from piglet age of 1 day to 3 weeks (P = 0.04). Overall, little nest-building-related behaviour occurred, probably due to the small amount of nest-building material. The usability of the nest-building material varied with farrowing treatment; FF sows used newspaper most for nest-building, while TC sows used straw and jute fabric (P = 0.01). There were no differences in the piglet birth intervals or the farrowing duration. In conclusion, free farrowing can have positive effects on piglet growth but negative effects on piglet survival in early lactation. Different nest-building materials have different effects depending on the type of farrowing system., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

To avoid a high body protein mobilization in modern lean sows during lactation, an adequate dietary amino acid (AA) supply and an efficient AA utilization are crucial. This study evaluated the effects of dietary CP and in vitro protein digestion kinetics on changes in sow body condition, litter weight gain, milk composition, blood metabolites, protein utilization efficiency and subsequent reproductive performance. We hypothesized that a slower digestion of dietary protein would improve AA availability and utilization. In total, 110 multiparous sows were fed one of four lactation diets in a 2 × 2 factorial design, with two CP concentrations: 140 g/kg vs 180 g/kg, and two protein digestion kinetics, expressed as a percentage of slow protein (in vitro degradation between 30 and 240 min): 8 vs 16% of total protein. Feeding sows the high CP diets reduced sow weight loss (Δ = 7.6 kg, P < 0.01), estimated body fat loss (Δ = 2.6 kg, P = 0.02), and estimated body protein loss (Δ = 1.0 kg, P = 0.08), but only at a high percentage of slow protein. A higher percentage of slow protein increased litter weight gain throughout lactation (Δ = 2.6 kg, P = 0.04) regardless of CP concentrations, whereas a higher CP only increased litter weight gain during week 3 of lactation (Δ = 1.2 kg, P = 0.01). On Day 15 postfarrowing, serial blood samples were taken from a subsample of sows fed with the high CP diets. In these sows, a high percentage of slow protein resulted in higher plasma AA concentrations at 150 and 180 min after feeding (Δ = 0.89, P = 0.02, Δ = 0.78, P = 0.03, mmol/L, respectively) and lower increases in urea at 90 and 120 min after feeding (Δ = 0.67, P = 0.04, Δ = 0.70, P = 0.03, mmol/L, respectively). The higher dietary CP concentration increased total nitrogen loss to the environment (Δ = 604 g, P < 0.01) with a reduction of protein efficiency (Δ = 14.8%, P < 0.01). In the next farrowing, a higher percentage of slow protein increased subsequent liveborn litter size (Δ = 0.7, P < 0.05). In conclusion, feeding sows with a high dietary CP concentration alleviated maternal weight loss during lactation when the dietary protein digestion rate was slower, but lowered protein efficiency. A slower protein digestion improved litter weight gain, possibly by reducing AA oxidation and improving plasma AA availability, thus, improving protein efficiency., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Early experiences can have long-term impacts on stress adaptability. This paper is the last of three in a series on early experiences and stress in pigs, and reports on the effects of early human contact and housing on the ability of pigs to cope with their general environment. Using a 2 × 2 factorial design, 48 litters of pigs were reared in either a farrowing crate (FC) or a loose farrowing pen (LP; PigSAFE pen) which was larger, more physically complex and allowed the sow to move freely. Piglets were provided with either routine contact from stockpeople (C), or routine contact plus regular opportunities for positive human contact (+HC) involving 5 min of scratching, patting and stroking imposed to the litter 5 days/week from 0 to 4 weeks of age. At 4 weeks of age (preweaning), C piglets that were reared in FC had considerably lower concentrations of serum brain-derived neurotrophic factor (BDNF) than piglets from the other treatment combinations. Compared to C pigs, +HC pigs had fewer injuries at 4 weeks of age. There were no clear effects of human contact on BDNF concentrations or injuries after weaning, or on basal cortisol or immunoglobulin-A concentrations, behavioural time budgets, tear staining, growth, or piglet survival. Compared to FC piglets, LP piglets showed more play behaviour and interactions with the dam and less repetitive nosing towards pen mates during lactation. There was no evidence that early housing affected pigs' behavioural time budgets or physiology after weaning. Tear staining severity was greater in LP piglets at 4 weeks of age, but this may have been associated with the higher growth rates of LP piglets preweaning. There was no effect of lactation housing on growth after weaning. Preweaning piglet mortality was higher in the loose system. The findings on BDNF concentrations, injuries and play behaviour suggest improved welfare during the treatment period in +HC and LP piglets compared to C and FC piglets, respectively. These results together with those from the other papers in this series indicate that positive human interaction early in life promotes stress adaptability in pigs. Furthermore, while the farrowing crate environment deprives piglets of opportunities for play behaviour and sow interaction, there was no evidence that rearing in crates negatively affected pig welfare or stress resilience after weaning. Whether these findings are specific to the two housing systems studied here, or can be generalised to other housing designs, warrants further research., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Survival of growing pigs through to slaughter age is not only a key driver of profitability but also has implications for animal welfare. Changing preweaning mortality by over 3% gives a similar change in profit per pig as changing postweaning mortality by 1%. There is significant scope to improve both traits through management and breeding to improve survival. The aim of this literature review was to explore the relationship between litter size and piglet birthweight and the detrimental impact this negative association has had on pig survival, along with genetic strategies that have been implemented in breeding programmes. It is suggested that the primary effect of litter size on mortality was indirect, through the effects of litter size on individual piglet birthweights. The circumstances affecting the litter a piglet was born into were the most important for determining the birthweight of individual piglets, rather than the genetic make-up of the individual piglet itself. Therefore, breeding programmes should include the average piglet birthweight of a litter (i.e., a sow trait) rather than individual piglet birthweight to maintain the weight of piglets at birth. The relative weighting of litter size and average piglet birthweight should be done in a manner that avoids selecting heavy pigs from small litters. Additional genetic strategies to improve survival include survival at the litter level, or survival of individual piglets or enhanced through the use of genomic information. At the litter level, litter size at day 5 and weaning can be considered as sow traits, but the use of these traits depends on the recording environment. At the individual piglet level, pre- and postweaning survival can be recorded as 0/1 traits and analysed directly. Although heritabilities are low for all these traits, genetic improvements can be made. For preweaning survival, the genes of the nurse sow are more important than the genes of the individual piglet. The nurse sow model captures both the lactation and gestation effects, and the information obtained when piglets born from different litters are reared together. However, once a piglet is weaned, its own genes became more important for the expression of postweaning mortality outcomes. Finally, for a successful selection programme, combining the average piglet birthweight at the litter level and mortality data based on individual piglet records (not solely birthweight) might yield the best response in piglet survival., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

There is considerable variation in the recommended minimum space allowance for growing pigs in scientific literature, and growing pressure, arising from recent reviews of current animal welfare standards for pigs, to increase the minimum space allowances set in legislation in some countries (e.g., European Union countries and New Zealand). The space provided for growing pigs needs to accommodate their physical body size in addition to social behaviour, activity, and essential functional behaviours. However, recommended minimum space allowances vary according to criteria such as temperature, live weight, flooring type, group size, behaviour, and enrichment availability. Though there may be justification for increasing current space requirements, this will present a practical issue on existing farms and could even result in unintended negative welfare outcomes, depending on how farmers address an increased requirement for space. This is not helped by inconsistent scientific approaches to assessing the effect of space on pig performance, and a lack of information on how space allowance impacts a pig's affective state. This review explores the scientific basis of the most common approaches to determining minimum space allowances for growing pigs and discusses the various factors that influence and interact with their spatial requirements. Consideration is given to their nutrition, physical environment, health, and behaviour to understand the welfare, performance, and practicality implications of differing recommendations for space allowance. More research is needed that investigates a range of space allowances to better understand the relationship between animal welfare and performance outcomes, and space allowance. This must replicate commercial conditions so that recommendations are relevant, future-focused, and achieve positive welfare outcomes in a practical but meaningful manner., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

The ability of pigs to cope with routine farming practices can affect their welfare. This paper is part of a series on early experiences and stress, and reports on the effects of early human contact and housing on the responses of pigs to routine husbandry practices. Using a 2 × 2 factorial design, 48 litters of pigs were raised in either a conventional farrowing crate (FC) or a loose farrowing pen (LP; PigSAFE pen) which was larger, more physically complex and allowed the sow to move freely. Piglets were provided with either routine contact from stockpeople (C), or routine contact plus regular opportunities for positive human contact (+HC) involving 5 min of scratching, patting and stroking imposed to the litter 5 days/week from 0 to 4 weeks of age. At 4 weeks of age, piglets were weaned and re-housed with controlled mixing of litters within treatment. At 4 days of age, after only 3 bouts of the handling treatment, +HC pigs showed less escape behaviour than C pigs after capture by a stockperson for vaccinations and tail docking, and shorter durations of vocalisations throughout the procedures. The  +HC pigs also showed less escape behaviour when captured by a stockperson at 3 weeks of age. The FC pigs showed less escape behaviour than LP pigs after capture by a stockperson at 4 days of age but not at 3 weeks of age. Serum cortisol concentrations were lower in FC pigs than LP pigs 2 h after weaning but not at 49 h after weaning, whereas serum cortisol concentrations were lower in  +HC pigs than C pigs at 49 h after weaning but not at 2 h after weaning. In the period from 0 to 1 h after weaning, C pigs from LP performed the most escape attempts, although escape attempts were rare overall. When being moved out of the home pen by a stockperson at 21 weeks of age, FC pigs showed less baulking than LP pigs, but there were no detected effects of human contact treatment. In conclusion, both housing system and human contact during lactation affected the stress responses of pigs to routine husbandry practices. The +HC and FC pigs appeared to cope better than C and LP pigs, based on lower responses indicative of stress including escape behaviour, vocalisations and cortisol concentrations. These findings are consistent with corresponding reductions in fear that were reported in Part 1 of this series of papers., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Not all boar sperm samples survive cryopreservation well. A method of eliminating damaged sperm might enable more cryopreserved boar semen to be used for pig breeding. In this study we investigated the use of Magnetic Activated Cell sorting (MACS) to eliminate damaged sperm from thawed boar semen samples. The thawed samples were mixed with Dead cell removal particles and were applied to the column in a SuperMACS II. Different fractions were collected: Original sample (O), Flow-through (FT), and Eluate (E). Sperm membrane integrity, mitochondrial membrane potential and reactive oxygen species were evaluated by flow cytometry after staining with SYBR 14 and propidium iodide, or 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethylbenzimidazolylcarbocyanine iodide, or hydroethidine and dichlorodihydrofluorescein diacetate, respectively. The FT samples had increased membrane integrity, a greater proportion of sperm with high mitochondrial membrane potential and a greater proportion of sperm negative for hydrogen peroxide than O samples (P<0.0001), which in turn had increased membrane integrity than E samples (P <0.0001). However, differences were seen between boars. The FT samples had increased values of live, superoxide positive sperm than O samples (P <0.0001) and O samples had greater values than E samples (P <0.0001), while there was no effect of boar. Sperm quality was best in the FT fraction, comprising approximately 32% of the sperm sample. In conclusion, although there were differences between boars, MACS separation can improve sperm quality in thawed semen samples. It would be interesting to see if this improvement is reflected in fertility outcomes., Competing Interests: Declaration of Competing Interest none, (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The development of fear and stress responses in animals can be influenced by early life experiences, including interactions with humans, maternal care, and the physical surroundings. This paper is the first of three reporting on a large experiment examining the effects of the early housing environment and early positive human contact on stress resilience in pigs. This first paper reports on the responses of pigs to humans, novelty, and social isolation. Using a 2 × 2 factorial design, 48 litters of pigs were reared in either a conventional farrowing crate (FC) where the sow was confined or a loose farrowing pen (LP; PigSAFE pen) which was larger, more physically complex and allowed the sow to move freely throughout the farrowing and lactation period. Piglets were provided with either routine contact from stockpeople (C), or routine contact plus regular opportunities for positive human contact (+HC) involving 5 min of scratching, patting and stroking imposed to the litter 5 days/week from 0-4 weeks of age. The positive handling treatment was highly effective in reducing piglets' fear of humans, based on +HC piglets showing greater approach and less avoidance of an unfamiliar person at 3 weeks of age. There was evidence that this reduction in fear of humans lasted well beyond when the treatment was applied (lactation), with +HC pigs showing greater approach and less avoidance of humans in tests at 6, 9 and 14 weeks of age. The +HC treatment also reduced piglets' fear of a novel object at 3 weeks of age, and for pigs in FC, the cortisol response after social isolation at 7 weeks of age. Rearing in FC compared to LP reduced piglets' fear of novelty at 3 weeks of age, as well as their vocalisations and cortisol response to isolation at 7 weeks of age. The FC pigs showed greater approach and less avoidance of humans compared to LP pigs at 3, 4 and 6 weeks of age, but not at 9 and 14 weeks of age. These results show that positive handling early in life can reduce pigs' fear of humans, fear of novelty and physiological stress response to social isolation. The LP pigs were reared in a more isolated environment with less overall contact with stockpeople and other pigs, which may have increased their fear responses to humans and novel situations, suggesting that different housing systems can modulate these pigs' responses., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Premating maternal nutrition is crucial for postweaning follicle growth, thereby influencing piglet birth weight in subsequent litters. The present study investigated the impact of supplementing a carbohydrate-rich premating diet in sows on metabolic hormones, subsequent piglet birth weight and reproductive performance. Sows were distributed into three groups, control (n=42) received standard diets; treatment I (n=41) received the same diets supplemented with 500 g of a carbohydrate-rich premating diet from weaning until insemination; treatment II (n=42) received the same diets supplemented with 500 g of a carbohydrate-rich premating diet from 7 days before weaning until insemination. Blood samples were taken from sows around weaning to measure serum insulin-like growth factor-1 and insulin, and blood glucose after feeding. The study found that sows on a carbohydrate-rich diet (treatment II) had higher postprandial glucose (P<0.05) and insulin levels (P=0.06) than others. This diet did not affect overall reproductive performance, but it did increase piglet birth weight and reduce the number of low-birth weight piglets compared to the control (P<0.001) and treatment I groups (P<0.05). Supplementing a carbohydrate-rich premating diet for 7 days before weaning until insemination enhanced postprandial glucose and insulin concentrations in weaned sows. This dietary intervention led to improved subsequent piglet birth weight and reduced the proportion of low-birth weight piglets.

Heat stress (HS) negatively impacts a variety of production parameters in growing pigs; however, the impact of biological sex on the HS response is largely unknown. To address this, 48 crossbred barrows and gilts (36.8 ± 3.7 kg BW) were individually housed and assigned to one of three constant environmental conditions: (1) thermoneutral (TN) (20.8 ± 1.6 °C; 62.0 ± 4.7% relative humidity; n = 8/sex), (2) HS (39.4 ± 0.6 °C; 33.7 ± 6.3% relative humidity) for 1 d (HS1; n = 8/sex), or (3) or for 7 d (HS7; n = 8/sex). As expected, HS increased rectal temperature (Tr) following 1 d of HS (1.0 °C; P < 0.0001) and 7 d of HS (0.9 °C; P < 0.0001). By 7 d, heat-stressed gilts were cooler than barrows (0.4 °C; P = 0.016), despite identical heating conditions. There was a main effect of sex such that barrows had higher Tr than gilts (P = 0.031). Heat-stressed pigs on d 1 had marked reductions in feed intake and BW compared to TN (P < 0.0001). One day of HS resulted in negative gain to feed (G:F) in barrows and gilts and was reduced compared to TN (P < 0.0001). Notably, following 1 d of HS, the variability of G:F was greater in gilts than in barrows. Between 1 and 7 d of HS, G:F improved in barrows and gilts and were similar to TN pigs, even though HS barrows had higher Tr than gilts over this period. Heat stress for 1 and 7 d reduced empty gastrointestinal tract weight compared to TN (P < 0.0001). Interestingly, HS7 gilts had decreased gastrointestinal tract weight compared to HS1 gilts (2.43 vs 2.72 kg; P = 0.03), whereas it was similar between HS1 and HS7 barrows. Lastly, a greater proportion of gastrointestinal contents was in the stomach of HS1 pigs compared to TN and HS7 (P < 0.05), which is suggestive of decreased gastric emptying. Overall, HS barrows maintained an elevated Tr compared to HS gilts through the duration of the experiment but also maintained similar growth and production metrics compared to gilts, despite this higher temperature., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

This study compared the follicular growth, superovulatory response, and in vivo embryo production after administering two doses of porcine follicle-stimulating hormone (pFSH) in Santa Inês ewes. The estrous cycle of 36 multiparous ewes was synchronized with the Day 0 protocol and superovulated with 133 mg (G133, n=18) or 200 mg (G200, n=18) of pFSH. Ultrasonographic evaluations of the ovaries were performed, ewes were mated and submitted to non-surgical embryo recovery. Viable blastocysts were stained with Nile Red and Hoechst. The G200 had a greater number of medium and large follicles, as well as a larger size of the third largest follicle. A total of 97.2% (35/36) of the ewes came into estrus and it was possible to transpose cervix in 80.6% (29/36). There were no effects of treatments in the response to superovulation, the proportion of ewes in which was possible to transpose the cervix, the number of corpora lutea, the number of anovulatory follicles, the proportion of ewes flushed with at least one recovered structure, number of recovered structures, number of viable embryos, viability rate, and recovery rate. The G200 ewes were in estrus for a longer period of time than the G133 ewes (54.0 ± 4.5 h vs. 40.3 ± 3.6 h) and produced more freezable embryos (6.5 ± 1.6 vs. 2.3 ± 0.7) than G133. Both doses promoted an efficient superovulatory response and did not affect embryonic lipid accumulation. The dose of 200 mg of pFSH showed greater potential to increase the superovulatory response, as it increased follicular recruitment and the recovery of freezable embryos., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

There is a gap in the understanding of the relationship between dietary phytate levels and the relative efficacy of phytase to improve amino acid (AA) digestibility in pigs and chickens. Two experiments were conducted to investigate the effect of exogenous phytase on standardized ileal digestibility (SID) of AA and the apparent ileal digestibility (AID) of P in both standard- (SP) and high-phytate (HP) diets for broilers and swine. There were either 40 cages of Cobb 500 male broilers or 10 crossbred barrows (35 kg) fitted with ileal T-cannulas. Both studies were allotted to five dietary treatments (8 replicates). Treatments consisted of four corn-soybean meal-based diets arranged in a 2 × 2 factorial of standard or high phytate and exogenous phytase at 0 or 1 000 phytase units (FYT)/kg; and one N-free diet. Birds were fed a common starter diet from d 0 to 20 and fed experimental diets from d 20 to 25. Birds were euthanized on d 25 via CO 2 asphyxiation, and digesta were collected from the terminal ileum. Pigs were fed for a total of four 7-d periods, where digesta were collected on d 6 and 7 of each period. Diet and digesta samples were analyzed for DM, N, Ti, AA, and P to determine AA and P digestibility. The SID of AA was determined by correcting the AID of AA for the basal endogenous losses estimated using the N-free diet. Main effects of the diet type (standard or HP) and phytase (0 or 1 000 FYT/kg), and the interaction of diet type and phytase were evaluated. For both experiments, the HP diets produced lower SID of AA compared to the SP (P < 0.001). For broilers, there was a phytase effect (P < 0.001) for the SID of all AAs evaluated regardless of the diet type. For pigs, phytase improved (P < 0.05) the SID of Met, Lys, Cys, Glu and Ser and tended to improve (P < 0.10) Arg, Leu, Thr, and Tyr. There were no significant interactions for either experiment. For both experiments, AID of P was lower for the HP diets (P < 0.01), and phytase produced greater AID of P for both diet types (P < 0.01). These data indicate that phytase greatly improves the digestibility of P for broilers and pigs and has the ability to significantly increase the digestibility of amino acids for these animals, regardless of the dietary phytate P., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Providing bedding or access to an outdoor run are husbandry aspects intended to improve pig welfare, which is currently financially supported through animal welfare schemes in several European countries. However, they may significantly affect the environment through changes in feed efficiency and manure management. Therefore, the aim of this paper was to compare farms differing in animal welfare relevant husbandry aspects regarding (1) the welfare of growing-finishing pigs and (2) environmental impact categories such as global warming (GW), acidification (AC), and freshwater (FE) and marine eutrophication (ME), by employing an attributional Life Cycle Assessment. We collected data on 50 farms with growing-finishing pigs in seven European countries. Ten animal-based welfare indicators were aggregated into three pig welfare indices using principal component analysis. Cluster analysis of farms based on husbandry aspects resulted in three clusters: NOBED (31 farms without bedding or outdoor run), BED (11 farms with bedding only) and BEDOUT (eight farms with bedding and outdoor run). Pigs on farms with bedding (BED and BEDOUT) manipulated enrichment more often (P < 0.001), pen fixtures less frequently (P = 0.003) and showed fewer oral stereotypies (P < 0.001) than pigs on NOBED farms. There were fewer pigs with a short(er) tail on farms with than without bedding (P < 0.001). Acidification of BEDOUT and BED farms was significantly higher (compared to NOBED farms P = 0.002) due to higher ammonia emissions related to farmyard manure. Also, BEDOUT farms had higher ME than NOBED farms (P = 0.035). There were no significant differences regarding GW and FE between husbandry clusters, due to the large variability within clusters regarding feed composition and conversion. Therefore, both husbandry aspects associated with improved animal welfare have a significant influence on some environmental impacts, such as acidification and marine eutrophication. Nevertheless, the large variation within clusters suggests that trade-offs may be minimised through e.g. AC and ME., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

In this short communication, we describe chewing behaviour in sows with no apparent edible substrate in their mouth as a potential social behaviour. Chewing in sows during interaction with unfamiliar sows was unexpectedly observed in a study assessing social abilities and damaging behaviours in group-housed dry sows. Such chewing was observed frequently and performed by almost all sows. To our knowledge, this behaviour has not been described previously in a social context in pigs, but rather as an oral stereotypic behaviour related to chronic hunger. We describe the behaviour in its social context and speculate on reasons for its occurrence in that context., (Copyright © 2024. Published by Elsevier B.V.)

Maternal recognition of pregnancy (MRP) is a term utilized in mammals to describe pathways in which the conceptus alters the endometrial environment to prevent regression of corpora lutea to ensure continued production of progesterone (P4) required for establishment and maintenance of pregnancy. For nearly 40 years after publication of the endocrine/exocrine theory, conceptus estrogen (E2) was considered the primary maternal recognition signal in the pig. Conceptus production of prostaglandin E2 (PGE2) was also considered to be a major factor in preventing luteolysis. An addition to E2 and PGE2, pig conceptuses produce interleukin 1B2 (IL1B2) and interferons (IFN) delta (IFND) and gamma (IFNG). The present review provides brief history of the discovery of E2, PGs and IFNS which led to research investigating the role of these conceptus secreted factors in establishing and maintaining pregnancy in the pig. The recent utilization of gene editing technology allowed a more direct approach to investigate the in vivo roles of IL1B2, E2, PGE2, AND IFNG for establishment of pregnancy. These studies revealed unknown functions for IFNG and ILB2 in addition to PGE2 and E2. Thus, pregnancy recognition signal is via a servomechanism in requiring sequential effects of P4, E2, IL1B2, PGE2 and IFNG. Results indicate that the original established dogma for the role of conceptus E2 and PGs in MRP is a far too simplified model that involves the interplay of numerous mechanisms for inhibiting luteolysis, inducing critical elongation of the conceptuses and resolution of inflammation in pigs., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Intrauterine growth restriction (IUGR) occurs both in humans and domestic species. It has a particularly high incidence in pigs, and is a leading cause of neonatal morbidity and mortality as well as impaired postnatal growth. A key feature of IUGR is impaired muscle development, resulting in decreased meat quality. Understanding the developmental origins of IUGR, particularly at the molecular level, is important for developing effective strategies to mitigate its economic impact on the pig industry and animal welfare. The aim of this study was to characterise transcriptional profiles in the muscle of growth restricted pig foetuses at different gestational days (GD; gestational length ~ 115 days), focusing on selected genes (related to development, tissue injury and metabolism) that were previously identified as dysregulated in muscle of GD90 fetuses. Muscle samples were collected from the lightest foetus (L) and the sex-matched foetus with weight closest to the litter average (AW) from each of 22 Landrace x Large White litters corresponding to GD45 (n = 6), GD60 (n = 8) or GD90 (n = 8), followed by analyses, using RT-PCR and protein immunohistochemistry, of selected gene targets. Expression of the developmental genes, MYOD, RET and ACTN3 were markedly lower, whereas MSTN expression was higher, in the muscle of L relative to AW littermates beginning on GD45. Levels of all tissue injury-associated transcripts analysed (F5, PLG, KNG1, SELL, CCL16) were increased in L muscle on GD60 and, most prominently, on GD90. Among genes involved in metabolic regulation, KLB was expressed at higher levels in L than AW littermates beginning on GD60, whereas both IGFBP1 and AHSG were higher in L littermates on GD90 but only in males. Furthermore, the expression of genes specifically involved in lipid, hexose sugar or iron metabolism increased or, in the case of UCP3, decreased in L littermates on GD60 (UCP3, APOB, ALDOB) or GD90 (PNPLA3, TF), albeit in the case of ALDOB this only involved females. In conclusion, marked dysregulation of genes with critical roles in development in L foetuses can be observed from GD45, whereas for a majority of transcripts associated with tissue injury and metabolism differences between L and AW foetuses were apparent by GD60 or only at GD90, thus identifying different developmental windows for different types of adaptive responses to IUGR in the muscle of porcine foetuses., (© 2024. The Author(s).)

A 4-week study was conducted to evaluate the effects of dietary crude protein ( CP ) content and resistant starch ( RS ) supplementation on growth performance, intestinal histomorphology and microbial metabolites of weaned pigs. A total of 96 pigs (7.06 ± 0.45 kg body weight) were assigned to 1 of 4 diets in a randomised complete block design involving a 2 (CP levels) × 2 (without or with RS) factorial arrangement to give 8 replicate pens and 3 pigs per pen. Body weight and feed disappearance were recorded weekly, and the faecal consistency score was determined every morning. Blood was sampled on days 1, 14 and 28 from one pig per pen, and the same pig was euthanised on day 28 to collect ileal tissue and ileal and colon digesta. Data were analysed using the MIXED procedure of SAS. The average daily gain and gain:feed ratio were lower ( p  < 0.05) in pigs fed low crude protein ( LCP ) diets compared to those fed high CP ( HCP ) diets during week 3 and overall period. The analysed Lys, Met+Cys and Thr in feed were lower than calculated values, particularly in LCP diets, which may have affected performance. Pigs fed the LCP diets had longer ( p  < 0.05) ileal villi and higher villus height to crypt depth ratios than those fed the HCP diets, and RS supplementation increased ( p  < 0.05) ileal villus height. Interactions ( p  < 0.05) between dietary CP content and RS inclusion were observed for short-chain fatty acid concentration in the ileum and colon in phase 2. There was no difference in propionic acid (ileum) or butyric acid (colon) concentrations among pigs fed HCP diets, however, the butyric acid concentration increased in pigs fed the LCP diet when supplemented with RS. Reducing dietary CP lowered ( p  < 0.05) faecal score, plasma urea nitrogen and digesta ammonia content. Overall, feeding LCP diets reduced growth performance but improved gut morphology in weaned pigs. Feeding the LCP diet with RS supplementation modulated concentrations of ileal propionic acid and colonic butyric acid in weaned pigs.

The aim was to determine ileal endogenous nitrogen losses (ENL) and true ileal N-digestibility (TD-N) under non-steady-state conditions of the 15 N-isotope dilution technique ( 15 N-IDT), using diets generating low and high ENL and compare results to those obtained under steady-state conditions. Twelve growing pigs (mean LW 22.4 kg) fitted with a post-valve T-caecum cannula were fed an enzyme-hydrolysed casein (EHC)-based diet or an EHC diet + 4% quebracho tannins (QT) and were labelled via continuous 15 N-leucine i.v . infusion or twice daily oral 15 N-leucine administration. Digesta were collected daily over three consecutive hours with blood plasma sampled on the four consecutive days after cessation of 15 N-labelling. There was a significant effect of sampling day on the dilution factor. Endogenous N losses were significantly lower for the EHC than the EHC+QT diet (2.41 vs. 8.69 g/kg DMI), while no significant effect of sampling day was observed. The TD-N of the EHC+QT diet did not differ from the TD-N of the EHC diet (95.1 vs. 92.0%). A significant effect of sampling day was observed for TD-N with day 1 and 2, being higher than day 4. Non-steady-state conditions overestimated ENL by 25-28% as compared to 3 h collections in steady-state conditions, but the relative overestimation was similar for the EHC diet as for the EHC+QT diet. TD-N did not differ significantly compared to 12 h steady-state measurements, but comparison to 3 h steady-state measurements showed that non-steady-state conditions overestimated TD-N for the EHC+QT diet by 9%. However, on day 4 this overestimation disappeared. Using the 15 N-IDT during non-steady-state conditions can provide valuable additional data on endogenous N losses and TD-N.

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.)

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 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.)

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 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.)

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.)