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A total of 105 sows (Line 241, DNA, Columbus, NE) were used across four batch farrowing groups to evaluate the effects of feeding a feed flavor in lactation diets on sow and litter performance. Sow groups 1 and 2 farrowed in an old farrowing facility during the summer months and groups 3 and 4 farrowed in a new farrowing facility during the winter months. Sows were blocked by body weight (BW) within parity on d 110 of gestation and allotted to 1 of 2 dietary treatments. Dietary treatments were a standard corn-soy-based lactation diet (control) or the control diet with the addition of a feed flavor at 0.05% of diet (Krave AP, Adisseo, Alpharetta, GA, USA). Farrowing facility environment had a large impact and resulted in many interactions with the feed flavor treatment. From farrowing to weaning, sows fed the feed flavor in the old farrowing house tended to have a higher (P = 0.058) lactation feed intake, while no difference in ADFI was observed in the new farrowing house. Pigs weaned from sows fed the feed flavor in the old farrowing facility had a higher (P = 0.026) BW at weaning and piglet average daily gain (ADG) from d 2 to weaning (P = 0.001) compared to piglets from sows not fed the feed flavor; whereas the opposite occurred in the new farrowing house. Progeny from one farrowing group in the old farrowing facility was followed into the nursery. A total of 360 weaned pigs (DNA 241 × 600: initially 5.7 kg) were used in a 2 × 2 factorial in the nursery portion of the study to evaluate the effects of previous sow feed flavoring treatment (control vs flavor) and nursery diets formulated with or without a feed flavor on growth performance in a 38-d trial. Nursery treatments were either a control diet or a diet containing a feed flavor (Delistart #NA 21, Adisseo, Alpharetta, GA, USA). Offspring from sows fed the flavor diet were heavier at weaning (P < 0.001) which was maintained throughout the study. Overall, progeny from sows fed a diet containing a feed flavor had greater (P < 0.05) ADG, ADFI, and final BW during the trial. The presence of a feed flavor in the nursery did not improve overall nursery performance. In conclusion, when sow lactation feed intake was increased in the old farrowing house, pigs weaned from sows fed the flavor diet were heavier (P = 0.039) at weaning compared to pigs weaned from sows fed the control diet. Adding the feed flavor increased sow feed intake and piglet ADG in a warm environment, but not in a cool environment.

A total of 21 litters (11 early and 10 late maturing Duroc × DNA 241) resulting in 241 pigs were used in 170 d trial to determine the effect of sire lines selected for either early or late maturing growth rates and creep feeding on the cortisol concentration, intestinal permeability, and growth performance of nursery and finishing pigs. Treatments were arranged in a 2 × 2 factorial with main effect of Duroc sire line (early or late maturing) and creep feeding (with or without). Creep feed was provided for 14 d prior to weaning. After weaning (approximately 21 days of age; initially 6.4 kg), no interactions were observed for blood cortisol. However, blood cortisol levels were increased (P = 0.011) in late maturing pigs compared to early maturing pigs. A lower percentage (P < 0.001) of early maturing pigs lost weight 3 d post-weaning compared to late maturing pigs. Likewise, early maturing pigs had improved (P < 0.001) ADG and ADFI during the first 3 d in the nursery and also had increased ADFI (P < 0.001) from d 2 to 14 in the nursery. Creep feeding had no effect on initial nursery performance. On d 7, after a 2 h fast, a subsample of pigs was administered an oral gavage of lactulose and mannitol dissolved in distilled water. No differences by sire line, creep feeding, or their interactions were observed in lactulose:mannitol ratio. For overall nursery growth performance, an interaction was observed for ADG (P = 0.007) and ADFI (P < 0.001), with creep feed providing a benefit in late maturing pigs, but not in early maturing pigs. Early maturing pigs had poorer G:F (P < 0.001) than late maturing pigs. For overall finishing performance, an interaction was observed for ADG (P = 0.037) and ADFI (P = 0.007), with creep feed providing a benefit in late maturing pigs, but not in early maturing pigs. This resulted in an interaction for final BW (P = 0.005), with late maturing pigs that did not receive creep feed having decreased market weights (P ≤ 0.003) compared to the other treatments. In summary, early maturing pigs had decreased cortisol concentration at weaning and improved ADG and ADFI until approximately 100 kg, at which point late maturing pigs began to exhibit greater ADG. Late maturing pigs had improved G:F from 46 d of age until market. Interestingly, creep feeding late maturing pigs resulted in increased d 170 weight compared with providing no creep feed, whereas creep feed did not impact early maturing pigs (sire line × creep feed interaction, P < 0.005).

Two experiments evaluated different fat sources and levels on growth performance, carcass characteristics, and economic impact in commercial finishing pigs. In experiment 1, 2,160 pigs (337 × 1,050, PIC; initially 37.3 ± 0.93 kg) were used. Pens of pigs were blocked by initial body weight and randomly assigned to one of four dietary treatments. Three of the four dietary treatments included: 0%, 1%, and 3% choice white grease. The final treatment contained no added fat until pigs were approximately 100 kg, and then a diet containing 3% fat was fed until marketing. Experimental diets were fed over four phases and were corn–soybean meal based with 40% distillers dried grains with solubles. Overall, increasing choice white grease decreased (linear, P = 0.006) average daily feed intake (ADFI) and increased (linear, P = 0.006) G:F. Pigs fed 3% fat only during the late-finishing phase (~100 to 129 kg) had similar G:F compared to pigs fed 3% for the entire study during the late-finishing phase, and intermediate G:F overall. Increasing fat tended to increase (linear, P = 0.068) hot carcass weight (HCW). Feed cost increased (linear, P ≤ 0.005) and income over feed cost decreased (linear, P ≤ 0.041) as choice white grease increased. In Experiment 2, 2,011 pigs (PIC 1,050 × DNA 600; initially 28.3 ± 0.53 kg) were used. Pens of pigs were blocked by location in the barn and randomly assigned to one of five dietary treatments arranged in a 2 × 2 + 1 factorial with main effects of fat source (choice white grease or corn oil) and level (1% or 3% of the diet) and a control diet with no added fat. Overall, increasing fat, regardless of source, increased (linear, P < 0.001) average daily gain (ADG), decreased (linear, P = 0.013) ADFI, and increased (linear, P < 0.001) G:F. Increasing fat increased (linear, P ≤ 0.016) HCW, carcass yield, and backfat depth. There was a fat source × level interaction (P < 0.001) in carcass fat iodine value (IV), where IV increased to a greater extent in pigs fed corn oil with only a small increase in IV in pigs fed diets with choice white grease. In conclusion, these experiments suggest that increasing fat from 0% to 3%, regardless of source, produced variable responses in ADG but consistently improved G:F. Increasing fat increased HCW, carcass yield, and backfat depth, but feeding diets containing corn oil increased carcass IV. With the ingredient prices used, the improvement in growth performance did not justify the extra diet cost from increasing fat from 0% to 3% in most situations.

A total of 600 sows (line 3; PIC, Hendersonville, TN) were used to evaluate the effect of different lactation feeder types and drip cooling on sow farrowing performance and litter growth performance during the summer. For the feeder evaluation, the trial was conducted in two sequential groups with 300 sows per group. Five 60-farrowing-stall rooms with tunnel ventilation were used for each group. On approximately days 110 to 112 of gestation, sows were blocked by body condition score (BCS), parity, and offspring sire (lines 2 or 3 sires; PIC), then randomly allotted to one of three feeder types: 1) PVC tube feeder, 2) Rotecna feeder (Rotecna), or 3) SowMax feeder (Hog Slat). The three feeder types were placed in one of three stalls with the same sequence from the front to the end of all rooms to balance for environmental effects. For drip cooling evaluation, the trial was conducted during the 2nd group of 300 sows. Drippers were blocked in three of every six farrowing stalls to balance feeder type and environmental effects. After farrowing, sows had ad libitum access to feed. For litter performance data, only pigs from sows bred to line 2 sires were recorded. Line 3 sire pigs were not included in litter performance data, but sows of these pigs were included in sow body weight (BW) and feed disappearance data. After weaning, feeder cleaning time was recorded on a subsample of 67 feeders (19, 23, and 25 for PVC tube, Rotecna, and SowMax, respectively). There was no evidence of difference (P > 0.05) in sow entry BW, exit BW, BW change, and litter performance among the different feeder types. However, sows using the SowMax feeders had decreased (P < 0.05) total feed disappearance, average daily feed disappearance, and total feed cost compared to those fed with the PVC tube feeders. There was a marginal difference (P < 0.10) between feeder types in cleaning time, with PVC tube feeders requiring less time than the Rotecna feeders; however, cleaning time varied greatly between the personnel doing the cleaning. Sows with drip cooling had greater (P < 0.05) feed disappearance, litter growth performance, and subsequent total born, and reduced (P < 0.05) BW change. In conclusion, using a SowMax feeder reduced feed disappearance with no effects on sow and litter performance compared to a PVC tube feeder, and drip cooling improved sow and litter performance during summer.

A total of 3,888 pigs (337 × 1050, PIC, Hendersonville, TN; initially 6.0 ± 0.23 kg) were used in a 35-d study. At the time of placement, pens of pigs were weighed and allotted to one of three dietary treatments in a randomized complete block design with a blocking structure including sow farm origin, date of entry into the facility, and average pen body weight. A total of 144 pens were used with 72 double-sided 5-hole stainless steel fence line feeders, with one feeder serving as the experimental unit. For each feeder, 1 pen contained 27 gilts, and 1 pen contained 27 barrows. There were 24 replicates per dietary treatment. Diets were fed in three phases, and all contained 0.3 mg/kg added Se. A common phase 1 diet contained added Se from sodium selenite and was fed in pelleted form to all pigs from day 7 to approximately day 0. Three Se sources sodium selenite, Se yeast, and hydroxy-selenomethionine (OH-SeMet) were used to formulate three experimental diets in meal form for phase 2 (days 0 to 14) and phase 3 (days 14 to 35). During the pre-treatment period (days 7 to 0), there was a tendency (P = 0.097) of a difference in average daily feed intake between treatments, although no significant pairwise differences were observed (P > 0.05). There were no other differences in growth performance between treatments from days 7 to 0. Clinical disease attributed to Streptococcus suis was observed within the trial between days 0 and 14, and water-soluble antimicrobial therapy was administered to all treatment groups for 7 d. From days 0 to 35, pigs fed OH-SeMet tended to have decreased average daily gain (P < 0.10) and increased (P < 0.05) serum and tissue selenium concentration compared to other treatments. There was marginally significant evidence of a source × day interaction (P = 0.027) for total antioxidant capacity where the numerical increase over time was less for the OH-SeMet than sodium selenite or selenium yeast treatments. There was no difference (P > 0.05) in antioxidant status as measured by serum glutathione peroxidase or thiobarbituric acid reactive substances assay between treatments. In summary, compared to sodium selenite and selenium yeast, OH-SeMet may have a greater bioavailability as indicated by increased serum and tissue selenium concentration; however, antioxidant status was similar between treatments and OH-SeMet tended to reduce growth performance compared with pigs fed sodium selenite.

Three experiments were conducted to determine the effect of sensory attractants pre- and post-weaning on the growth performance of pigs after weaning. For each experiment, treatments were arranged as a 2 × 2 × 2 factorial with main effects of pre-weaning application (without or with), post-weaning application (without or with), and body weight category (representing the lightest or heaviest 50% of the population). In Exp. 1, 356 nursery pigs (initially 5.7 kg) were used in a 28-d trial with enrichment cubes used as the sensory attractant. A greater percentage of heavy pigs (P = 0.007) or pigs offered enrichment cubes pre-weaning (P = 0.044) lost BW from weaning to d 3 compared to light pigs or pigs not offered enrichment cubes pre-weaning. From weaning to d 7, a greater percentage of pigs lost weight when not offered cubes post-weaning (P = 0.002) compared to pigs offered cubes post-weaning. In Exp. 2, 355 nursery pigs (initially 5.6 kg) were used in a 29-d trial with a powder used as the sensory attractant. Providing a powder attractant both pre- and post-weaning reduced the percentage of pigs that lost weight from weaning to d 3 as compared with providing a powder either pre- or post-weaning only (interaction, P

Three experiments were conducted to determine the effects of increasing soybean meal (SBM) levels by replacing feed-grade amino acids (AA) in corn, corn dried distillers grains with solubles (DDGS), and corn-wheat midds-based diets on growth performance of late finishing pigs (n = 4,406) raised in commercial facilities. Across all experiments, pens of pigs were blocked by initial bodyweight (BW) and randomly assigned to 1 of 5 dietary treatments. All diets were formulated to contain 0.70% standardized ileal digestible (SID) Lys and varying amounts of feed-grade AA. All diets were formulated to meet or exceed minimum essential AA requirement estimates as a ratio to Lys. In Exp. 1, 1,793 pigs (initially 104.9 ± 4.9 kg) were fed corn-based diets and pens of pigs were assigned treatments with increasing SBM from 5% to 20%. Overall, average daily gain (ADG) and feed efficiency (G:F) improved (linear and cubic, P ≤ 0.02) as dietary SBM increased, with the greatest improvement observed as SBM increased from 5% to 8.75% and little improvement thereafter. In Exp. 2, 1,827 pigs (initially 97.9 ± 4.3 kg) were fed diets containing 25% DDGS with SBM levels increasing from 0% to 16%. Overall, feed efficiency marginally improved (linear, P ≤ 0.10) as SBM increased, with the greatest performance observed when diets contained 8% SBM and similar performance thereafter with 12 or 16% dietary SBM. In Exp. 3, 786 pigs (initially 96.7 ± 3.2 kg) were fed diets that contained 30% wheat midds and dietary SBM from 0% to 16%. Final BW of pigs increased (linear, P < 0.05) and overall ADG and G:F improved (linear and cubic, P < 0.05) as SBM increased. The combined results of the three experiments suggest that inclusion of at least 4% to 8% dietary SBM at the expense of feed-grade amino acids in corn-based diets with or without grain coproducts can improve growth performance of late-finishing (greater than 100 kg) pigs.

Four experiments were conducted to determine the effect of mat feeding strategy on the growth performance, removal, and mortality of pigs after weaning. In exp. 1, 1,392 weanling pigs (initially 7.0 kg; approximately 24 d of age) were randomly allotted to 1 of 2 mat feeding treatments (mat feed vs. no mat feed). Overall, mat fed pigs had a tendency for improved ADG (P = 0.065) and G:F (P = 0.060) compared to pigs not offered mat feed. Mat fed pigs had fewer removals (P = 0.013) compared to pigs not offered mat feed. In exp. 2, 2,912 weanling pigs (initially 5.5 kg; approximately 21 d of age) were randomly allotted to 1 of 2 mat feeding treatments (mat feed vs. no mat feed). Overall, no differences in growth performance were observed. However, mat fed pigs had decreased (P < 0.026) final body weights compared to pigs not offered mat feed. This may be related to removal rates as mat fed pigs had fewer removals (P = 0.026). In exp. 3, 3,264 weanling pigs (initially 5.5 kg; approximately 21 d of age) were randomly allotted to 1 of 4 treatments in a 2 × 2 factorial with main effects of diet form (pellet or crumble) and mat feeding (mat feed vs. no mat feed). No interactions between diet form and mat feeding were observed. No differences were observed in overall growth performance for the main effect of mat feeding. Pigs offered pelleted feed had decreased overall ADFI (feed disappearance from the feeder and feed placed on the mat; P = 0.013) and improved G:F (P < 0.001) compared to pigs offered crumble feed. No differences were observed in removals or mortalities for the main effect of mat feeding or diet form. In exp. 4, 3,227 weanling pigs (initially 5.1 kg; approximately 21 d of age) were randomly allotted to 1 of 3 treatments consisting of mat feeding small (3.2 mm) pellets, mat feeding large (12.7 mm) pellets, or no mat feeding. Overall, no differences were observed in ADG or G:F. Mat fed pigs had increased ADFI (P < 0.001) compared to pigs not offered mat feed. Given the shorter duration of this experiment, the extra feed provided with mat feeding had a greater impact on overall feed usage than exp. 1, 2, and 3. No differences were observed in removals or mortalities. When combining the removal and mortality data for the four experiments, mat fed pigs had fewer removals (P = 0.002) compared to pigs not offered mat feed. In summary, mat feeding may encourage earlier feeding behavior, therefore reducing the removal rate of pigs post-weaning.

Three experiments were conducted to evaluate fermented corn protein (FCP) in nursery pig diets. The removal of non-fermentable components before fermentation of DDGS results in high protein dried distillers grains (HPDDGs). Fermented corn protein is produced when protein and yeast fraction syrup from ethanol production is added back to HPDDGs resulting in a product with up to 50% CP and 2% Lys. In Exp. 1, 350 barrows, initially 6.0 kg, were used to evaluate FCP as a replacement to enzymatically treated soybean meal. Treatments were arranged in a 2 × 2 + 1 factorial with main effects of specialty protein source (FCP or enzymatically treated soybean meal) and level (5 or 10%) or a control diet without any specialty protein source. There were 5 pigs per pen and 14 replications per treatment. From d 0 to 31, pigs fed enzymatically treated soybean meal had improved (P 0.05) in feed consumption of diets containing whole stillage solids compared to FCP. Pigs preferred (P = 0.001) the diet containing thin stillage solids by consuming 75.8% of their intake with this diet compared to the diet containing FCP. In conclusion, feeding FCP decreased growth performance in nursery pigs, but increasing Ile + Val:Leu improved G:F. Diet preference comparisons suggest that whole stillage solids are the component of FCP that leads to reduced feed intake.

Dietary cation–anion difference (DCAD), calculated as Na+ + K+ – Cl− in mEq/kg of the diet, represents the influence that monovalent cations and anions from these minerals have on the acid–base status of the animal. However, the recommended range of DCAD for optimal grow-finish swine performance is variable, which may indicate an interaction between DCAD and other ingredients. The hypothesis for this study was that the addition of potassium bicarbonate (KHCO3) to increase diet DCAD when high levels of l-Lys HCl (>0.35% diet) are used may potentially improve growth performance. A total of 1,944 pigs (PIC L337 × 1050, initially 35.2 ± 0.85 kg) were used in a 120-d study. Pens of pigs were blocked by BW and randomly allotted to 1 of 4 dietary treatments in a randomized complete block design. Treatments were arranged in a 2 × 2 factorial with main effects of KHCO3 (0% or 0.4%), and l-Lys HCl level (low or high). l-Lys HCl was included between 0.13% and 0.21% in low diets, and between 0.36% and 0.43% in high diets. There were 27 pigs per pen and 18 replicates per treatment. Treatment diets were corn-soybean meal-based and formulated in four dietary phases (35–60 kg, 60–85 kg, 85–105 kg, and 105–130 kg). Dietary treatments were formulated such that in each phase the diet containing a low level of l-Lys HCl without KHCO3 and the diet containing a high level of l-Lys HCl with KHCO3 had similar calculated DCAD values (169–232 mEq/kg). Additionally, the diet with a low level of l-Lys HCl with KHCO3 was formulated to have the highest DCAD in each phase (220–281 mEq/kg), while the diet with a high level of l-Lys HCl without KHCO3 was formulated to have the lowest DCAD (118–182 mEq/kg). Overall, there was no evidence (P > 0.10) for a KHCO3 × l-Lys HCl interaction or main effect for final BW or any observed growth response or carcass characteristics. The results of this study suggest that supplementing KHCO3 to finishing pig diets with either high or low levels of l-Lys HCl and the corresponding changes in DCAD values did not impact growth performance or carcass characteristics.

Some ingredients bind more acid in the stomach than others which can increase gastric pH in weaned pigs causing decreased protein digestion and allow pathogenic micro-organisms to proliferate. Our objective was to measure acid-binding capacity at a pH of 4 (ABC-4) of common nursery ingredients and determine additivity in diets. Ingredient categories included: cereal grains, vegetable proteins, animal proteins and milk, vitamin premixes and minerals, amino acids, and fiber sources. A 0.5-g sample of each ingredient was suspended in 50 mL of distilled deionized water and titrated with 0.1-N hydrochloric acid. Sample ABC-4 was calculated as the amount of acid in milliequivalents (meq) required to lower 1 kg to a pH of 4. Cereal grains were found to have lower ABC-4 compared to other ingredients. Vegetable proteins had higher ABC-4 with more variation than cereal grains. Soybean meal (SBM) had an ABC-4 of 602 ± 28.2 meq. Soy protein concentrate and enzymatically treated soybean meal (ESBM) had higher ABC-4 compared to SBM while fermented soybean meal (FSBM) was lower. Zinc oxide (ZnO) and calcium carbonate (CaCO3) had the highest ABC-4 among all ingredients with values of 21,863 ± 598.7 and 18,384 ± 769.7 meq, respectively. Following ingredient analysis, a series of diets were analyzed to determine additivity by comparing the differences between calculated and analyzed ABC-4 value. All diets analyzed had lower ABC-4 than calculated values; however, analyzed ABC-4 increased along with calculated values across diets. The first series of diets were arranged in a 2 × 5 factorial consisting of increasing CaCO3 with or without ZnO. There was a ZnO × CaCO3 interaction (P = 0.020) for difference between calculated and analyzed ABC-4. Within the interaction, differences between calculated and analyzed ABC-4 increased (linear, P

Pork hot carcass weights (HCW) have been increasing 0.6 kg per year, and if they continue to increase at this rate, they are projected to reach an average weight of 118 kg by the year 2050. This projection in weight is a concern for pork packers and processors given the challenges in product quality from heavier carcasses of broiler chickens. However, previous work demonstrated that pork chops from heavier carcasses were more tender than those from lighter carcasses. Therefore, the objective was to determine the effects of pork hot carcass weights, ranging from 90 to 145 kg with an average of 119 kg, on slice shear force and sensory traits of Longissimus dorsi chops when cooked to 63 or 71 °C, and to assess if differences in chilling rate can explain differences in sensory traits. Carcasses were categorized retrospectively into fast, medium, or slow chilling-rates based on their chilling rate during the first 17 h postmortem. Loin chops cut from 95 boneless loins were cooked to either 63 or 71 °C and evaluated for slice shear force and trained sensory panel traits (tenderness, juiciness, and flavor) using two different research laboratories. Slopes of regression lines and coefficients of determination between HCW and sensory traits were calculated using the REG procedure in SAS and considered different from 0 at P ≤ 0.05. As hot carcass weight increased, chops became more tender as evidenced by a decrease in SSF (63 °C β = -0.0412, P = 0.01; 71 °C β = -0.1005, P0.001). Furthermore, HCW explained 25% (R2 = 0.2536) of the variation in chilling rate during the first 5 h of chilling and 32% (R2 = 0.3205) of the variation in chilling rate from 5 to 13 h postmortem. Slow- and medium-rate chilling carcasses were approximately 12 kg heavier (P0.05) than fast chilling carcasses. Slice shear force of chops cooked to 63 and 71 °C was reduced in slow and medium chilling compared with fast chilling carcasses. Carcass temperature at 5 h postmortem explained the greatest portion of variation (R2 = 0.071) in slice shear force of chops cooked to 63 °C. These results suggest that carcasses tend to chill slower as weight increases, which resulted in slight improvements in sensory traits of boneless pork chops regardless of final degree of doneness cooking temperature.Pork carcass weights have increased year over year for at least the past 25 yr. The poultry industry has experienced similar increases in carcass weights in the recent past. The increases in broiler carcass weights have resulted in detrimental impacts on quality. Contrary to the poultry industry, increases in pork carcass weights have resulted in a general improvement in pork quality, including tenderness. The underlying cause of these improvements has not been explained. In the present study, chilling rate was associated with carcass weights, particularly during the first 5 h postmortem. In fact, carcass temperature measured in the Longissimus dorsi muscle at 5 h postmortem was the most predictive of instrumental tenderness values when boneless pork chops were cooked according to UDSA guidelines for whole-muscle pork products. The metabolic conversion of muscle to meat is most active during this initial chilling period. Therefore, chilling rate, which is associated with carcass weight, may be influencing the conversion of muscle to meat and provide some explanation as to why heavy carcasses result in more tender pork chops.

A total of 4,318 pigs (337 × 1,050, PIC; initially 6.5 ± 0.08 kg) were used in a 35-day study to evaluate dietary mycotoxin control strategies on nursery pig performance and blood measures. Pigs were weaned at approximately 21 d of age and randomly allotted to 1 of 5 dietary treatments in a randomized complete block design with blocking structure including sow farm origin, date of entry into facility, and average pen BW. A total of 160 pens were used with 80 double-sided 5-hole stainless steel fence line feeders, with feeder serving as the experimental unit. For each feeder, 1 pen contained 27 gilts and 1 pen contained 27 barrows. There were 16 replications per dietary treatment. A common phase 1 diet was fed to all pigs in pelleted form for 7 day prior to treatment diets. Experimental treatments were fed from days 7 to 42 after weaning (days 0 to 35 of the study) and included a low deoxynivalenol (DON) diet (1.12 ± 0.623 mg/kg), high DON diet (2.34 ± 1.809 mg/kg), high DON+ 0.50% sodium metabisulfite (SMB), high DON+ one of two mitigating products; 0.30% Technology1, or 0.30% Technology1+. Technology1 and 1+ are comprised of clays, yeast cell wall components, and a blend of plant extracts. Technology1+ also contains SMB. Overall (days 0 to 35), pigs fed high DON had decreased (P < 0.05) final BW, ADG, and ADFI compared with low DON. Additionally, pigs fed high DON+SMB had increased (P < 0.05) ADG compared with all other treatments. An improvement (P < 0.05) in G:F was observed in pigs fed high DON + SMB or high DON + Technology1+ compared with the low DON or high DON + Technology1 diets with high DON diets intermediate. Pigs fed high DON + SMB or high DON + Technology1 diets had reduced (P < 0.05) total removals and mortality compared with pigs fed low DON diets with high DON and high DON + Technology1+ intermediate. Liquid chromatography/mass spectrometry analysis of circulating blood collected on day 35 revealed that pigs fed high DON or high DON + Technology1 had increased (P < 0.05) DON concentrations compared to low DON with high DON + SMB and high DON + Technology1+ intermediate. In summary, pigs fed high DON diets had reduced performance compared with pigs fed low DON. Sodium metabisulfite in high DON diets provided a benefit in growth performance with ADG and G:F exceeding growth performance in the low DON diet while, the improved G:F ratio combined with other immunometabolic changes (gamma glutamyltransferase and creatine kinase) associated with Technology1+ warrant further investigation.

Mixed parity sows (n = 3,451; PIC, Hendersonville, TN; parities 2 through 9) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. Our hypothesis, like observed in earlier research, was that increasing linoleic acid (LA) and α-linolenic acid (ALA) would improve sow and litter performance. At approximately day 112 of gestation, sows were randomly assigned within parity groups to 1 of 4 corn-soybean meal-wheat-based lactation diets that contained 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low LA and ALA in diets with CWG or high LA and ALA in diets that included soybean oil. Sows received their assigned EFA treatments until weaning and were then fed a common gestation and lactation diet in the subsequent reproductive cycle. Average daily feed intake during the lactation period increased (P0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. However, daily LA and ALA intakes of sows fed the Combination and SO diets were still greater (P0.05) than those of sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P0.05) piglet weaning weights and greater (P0.05) litter ADG when compared with litters from sows fed diets with CWG that provided low EFA. Despite advantages in growth performance, there was no impact of sow EFA intake on piglet survivability (P0.10). Additionally, lactation diet EFA composition did not influence sow colostrum or milk dry matter, crude protein, or crude fat content (P0.10). However, LA and ALA content in colostrum and milk increased (P0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by soybean oil during lactation increased overall litter growth and pig weaning weights, reduced sow ADFI, but did not affect piglet survivability or subsequent performance of sows.Supplemental fat sources are an effective and widely accepted strategy to increase energy density of sow lactation diets that can also provide essential fatty acids such as linoleic acid (LA) and α-linolenic acid (ALA). Currently, the effects of supplemental LA and ALA provided shortly before farrowing on colostrum and milk composition are not fully understood. Additionally, the influence of elevated LA and ALA provided in sow lactation diets on litter growth and survivability responses has not been extensively evaluated. Therefore, this trial was conducted to evaluate the effects of fat sources providing low and high LA and ALA intake on sow performance, litter growth and survivability, colostrum and milk composition, and subsequent reproductive performance. Overall, sows consuming diets with high LA and ALA provided by soybean oil produced litters with heavier piglet weaning weights and greater litter average daily gain when compared with sows consuming diets with low LA and ALA content. Increasing LA and ALA by added soybean oil also increased their content in colostrum and milk. However, there was no influence of sow LA and ALA intake on litter survivability or subsequent reproductive performance of sows.

Two experiments were conducted to determine the impact of various combinations of yeast-based direct fed microbials (DFM) in diets fed to nursery pigs weaned from sows fed lactation diets with or without yeast additives. In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs. yeast additives) and nursery diets with or without added yeast-based DFM on growth performance and antimicrobial resistance (AMR) patterns of fecal Escherichia coli. Treatments were arranged in a 2 × 2 factorial with main effects of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+ and 0.025% SafMannan, Phileo by Lesaffre, Milwaukee, WI) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc 47 HR+, 0.05% SafMannan, and 0.05% NucleoSaf from days 0 to 7, then concentrations were decreased by 50% from days 7 to 24) with 5 pigs per pen and 17 replications per treatment. Progeny from sows fed yeast additives had increased (P0.05) average daily gain (ADG) from days 0 to 24 and days 0 to 45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased days 0 to 45 ADG (P = 0.079). Fecal E. coli isolated from pigs from the sows fed yeast group had increased (P = 0.034) resistance to nalidixic acid and a tendency for increased resistance to ciprofloxacin (P = 0.065) and gentamicin (P = 0.054). Yet, when yeast additives were added in the nursery, there was reduced (P0.05) fecal E. coli resistance to azithromycin and chloramphenicol. In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with two different combinations of DFM on growth performance. Treatments were arranged in a 2 × 3 factorial with main effects of sow treatment (same as described in Exp. 1) and nursery treatment (control; YCW, 0.05% of SafMannan from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24; or DFM, 0.10% MicroSaf-S from days 0 to 38 and NucleoSaf at 0.05% from days 0 to 10 and 0.025% from days 10 to 24) with 6 pigs per pen and 8 to 10 replications per treatment. From days 0 to 10 post-weaning, progeny of sows fed yeast additives had increased (P0.05) ADG and G:F. In conclusion, feeding sows yeast through lactation improved offspring growth performance in the nursery. Although feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1, feeding DFM improved growth later in the nursery period in Exp. 2.Feeding sows a diet containing live yeast and yeast extract from day 110 of gestation through weaning resulted in progeny that were heavier at weaning and had increased average daily gain and average daily feed intake throughout the nursery period. However, feeding yeast additives to pigs only in the nursery tended to reduce average daily gain. Fecal E. coli isolates from offspring that were fed yeast showed tendency towards antimicrobial resistance among fecal E. coli isolates to nalidixic acid, ciprofloxacin, and gentamicin. Yet, feeding live yeast and yeast extracts in the nursery phase may reduce the antimicrobial resistance of fecal E. coli to azithromycin and chloramphenicol.

A total of 80 sows (Line 241; DNA, Columbus, NE) across three farrowing groups were used in a study to evaluate the effect of feeding live yeast and yeast extracts to lactating sows on sow and litter performance and antimicrobial resistance (AMR) patterns of sow fecal E. coli. Sows were blocked by farrowing group, BW, and parity on day 110 of gestation and allotted to 1 of 2 dietary treatments. Dietary treatments consisted of a standard lactation diet with or without yeast-based pre- and probiotics (0.10% Actisaf Sc 47 HR+ and 0.025% SafMannan; Phileo by Lesaffre, Milwaukee, WI). Diets were fed from day 110 of gestation until weaning (approximately d 19 post-farrow). A tendency (P = 0.073) was observed for increased feed intake through lactation when sows were fed a diet with yeast additives compared with the control diet. There was no evidence (P0.10) that treatment influenced any other sow or litter performance measurements. Fecal samples were collected upon entry into the farrowing house and at weaning from the first farrowing group (27 sows) to determine the resistance patterns of E. coli. E. coli was isolated from fecal samples and species confirmed by PCR detection of uidA and clpB genes. Microbroth dilution method was used to determine the minimal inhibitory concentrations (MIC) of E. coli isolates to 14 antimicrobials. Isolates were categorized as either susceptible, intermediate, or resistant based on Clinical and Laboratory Standards Institute guidelines. An interaction (P = 0.026) of diet × sampling day was observed for cefoxitin where fecal E. coli showed no evidence of treatment differences (P = 0.237) in MIC values at entry, but sows fed the control diet had lower (P = 0.035) MIC values at weaning compared with sows fed yeast additives. There were no diet main effects (P0.10) on the resistance of fecal E. coli. There was an increased (P0.02) toward resistance for 11 of the 14 antimicrobials over time. Fecal E. coli were resistant to tetracycline and ceftriaxone at weaning. Fecal E. coli were susceptible or intermediate in all sampling days to the remaining antimicrobials. In conclusion, feeding live yeast and yeast extracts tended to increase feed intake during lactation but did not influence either sow or litter performance measurements or the resistance of fecal E. coli during lactation except for cefoxitin, which had a higher MIC at the end of lactation when yeast additives were present in the diet.Feeding sows live yeast and yeast extracts from day 110 of gestation through lactation tended to increase lactation feed intake but did not affect any other sow or litter performance criteria. Live yeast and yeast extracts in the diet had minimal effect on the antimicrobial resistance of fecal E. coli isolates. Regardless of the diet, fecal E. coli isolates were susceptible to 11 of the 14 antimicrobials when sows entered the farrowing house. But most of the antimicrobials were classified as intermediate or with a tendency toward resistance at weaning even though none of these antibiotics were used during the lactation period. Our findings agree with other cross-sectional studies on AMR where high AMR gene levels reported among young pigs were attributed to sow population.

Corn distillers dried grains with solubles (DDGS) is commonly available and often can lower diet cost for swine diets. This corn co-product is recognized to be a source of dietary insoluble fiber, which can not only increase the villous length of the gut mucosa but also increase intestinal production of mucin. Mucin structure, functions, and synthesis are correlated to Thr intake; consequently, the dietary Thr level may need to be increased when feeding an insoluble fiber source such as corn–DDGS. Thus, the objective of this study was to evaluate if feeding standardized ileal digestible (SID) Thr:Lys ratio at or above the estimated requirement in diets without and with DDGS would influence growth performance in finishing pigs. A total of 2,160 pigs (PIC 337 × 1,050; initially 35.1 ± 0.5 kg) were used in a 112-d growth trial. Pigs were randomly assigned to pens (27 pigs per pen) in a randomized complete block design by body weight (BW) with 20 replications per treatment. Pens of pigs were allotted to one of four dietary treatments that were arranged in a 2 × 2 factorial with main effects of dietary Thr level (normal vs. high) and DDGS (without or with). Treatment diets were formulated in four phases from 34 to 57, 57 to 79, 79 to 104, and 104 to 130 kg BW. Diets with high DDGS were formulated to include 40% DDGS in phases 1 and 2, 30% in phase 3, and 15% in phase 4. The normal Thr diets were formulated to contain 61%, 62%, 63%, and 65% SID Thr:Lys ratios for the four dietary phases, respectively. High Thr diets had SID Thr:Lys ratios of 67%, 68%, 69%, and 72%, respectively. There were no interactions (P > 0.10) observed in any phase or overall between Thr level and added DDGS. For the overall period (day 0 to 112), pigs fed diets without DDGS had increased (P < 0.001) average daily gain (ADG) but reduced (P < 0.001) average daily feed intake (ADFI), leading to increased (P < 0.001) feed efficiency (gain-to-feed ratio [G:F]). There was no evidence for difference (P > 0.10) between pigs fed diets formulated at normal or high SID Thr:Lys ratio. In summary, feeding high levels of DDGS decreased ADG and increased ADFI, which resulted in decreased G:F and lower final BW, regardless of the dietary SID Thr:Lys ratio level. In the current study, increasing the level of digestible Thr in a diet that contained a highly insoluble fiber source did not increase the growth performance of grow-finish pigs.

Shiga toxin-producing Escherichia coli (STEC) are major foodborne human pathogens that cause mild to hemorrhagic colitis, which could lead to complications of hemolytic uremic syndrome. Seven serogroups, O26, O45, O103, O111, O121, O145, and O157, account for the majority of the STEC illnesses in the United States. Shiga toxins 1 and 2, encoded by stx1 and stx2, respectively, and intimin, encoded by eae gene, are major virulence factors. Cattle are a major reservoir of STEC, but swine also harbor them in the hindgut and shed STEC in the feces. Our objectives were to use a culture method to isolate and identify major and minor serogroups of STEC in finisher pig feces. Shiga toxin genes were subtyped to assess public health implications of STEC. Fecal samples (n = 598) from finisher pigs, collected from 10 pig flows, were enriched in E. coli broth and tested for stx1, stx2, and eae by a multiplex PCR (mPCR) assay. Samples positive for stx1 or stx2 gene were subjected to culture methods, with or without immunomagnetic separation and plating on selective or nonselective media, for isolation and identification of stx-positive isolates. The culture method yielded a total of 178 isolates belonging to 23 serogroups. The three predominant serogroups were O8, O86, and O121. The 178 STEC strains included 26 strains with stx1a and 152 strains with stx2e subtypes. Strains with stx1a, particularly in association with eae (O26 and O103), have the potential to cause severe human infections. All stx2-positive isolates carried the subtype stx2e, a subtype that causes edema disease in swine, but is rarely involved in human infections. Several strains were also positive for genes that encode for enterotoxins, which are involved in neonatal and postweaning diarrhea in swine. In conclusion, our study showed that healthy finisher pigs harbored and shed several serogroups of E. coli carrying virulence genes involved in neonatal diarrhea, postweaning diarrhea, and edema disease, but prevalence of STEC of public health importance was low. HIGHLIGHTS

Shiga toxin-producing Escherichia coli (STEC) are major foodborne pathogens and seven serogroups, O26, O45, O103, O111, O121, O145, and O157, that account for the majority of the STEC-associated il...

Pigs [n = 882; initial body weight (BW) of 33.2±0.31 kg] were used to evaluate the effects of different bones and analytical methods on assessment of bone mineralization response to dietary P, phytase, and vitamin D in growing-finishing pigs. Pens of pigs (20 pigs/pen) were completely randomized to 5 dietary treatments with 9 pens/treatment. After feeding diets for 112-d, nine pigs/treatment were harvested for bone analysis. Treatments were: 1) P at 80% of the NRC STTD P (deficient), 2) NRC STTD P using monocalcium phosphate, 3) NRC STTD P including phytase, 4) Industry P using monocalcium phosphate and phytase, 5) diet 4 with additional 2,000 IU/kg 25(OH)D3 (HyD). All diets contained vitamin D at 1,653 IU/kg. There were no significant differences for final BW, ADG, ADFI, G:F (P>0.10) or non-de-fat bone ash (bone ash×bone interaction, P>0.10). The response to treatment for bone density (Archimedes principle) and bone mineral content (DEXA) tended to depend on the bone (density×bone interaction, P=0.053; mineral density×bone interaction, P=0.157). There were no treatment differences (P>0.10) for bone density and bone mineral density between metacarpals, fibulas, and 2nd ribs. For 10th ribs, pigs fed industry levels of P had increased (P< 0.05) bone density compared with pigs fed NRC levels with phytase, with pigs fed deficient P, NRC P with no phytase, and excess vitamin D from HyD being intermediate. Pigs fed diets supplemented with HyD had increased bone mineral density in 10th ribs compared with pigs fed NRC levels of P with phytase, with pigs fed P deficient diets, industry P without HyD, and NRC P with monocalcium being intermediate. In summary, bone density and bone mineral content responses varied depending on the bone. Differences in bone density and mineral content in response to vitamin D and P were most apparent with the 10th ribs.

From November, 2021 to February, 2022, swine nutritionists representing 29 production systems and 8 nutrition supplier companies in the United States were surveyed about added vitamin concentration in swine diets. Respondents were asked to provide vitamin premix concentrations, inclusion rates, and weight ranges associated with feeding phases. Survey participants represented 4.38 million sows or 69% of the U.S. industry. Data were compiled into 3 nursery phases (Phase 1, weaning to 7 kg; Phase 2, 7 to 11 kg; and Phase 3, 11 to 23 kg), 3 finishing phases (23 to 55 kg; 55 to 100 kg; 100 to market), gestation, and lactation (Table 1). Vitamin concentrations were, on average, 3.9 times above NRC (2012) recommendations across all nursery diets. Vitamins D and K were the upper extremes, and choline and pyridoxine were the lower. In finishing diets, vitamin concentrations averaged 2.8 times the 2012 NRC recommendations. Vitamins D and K were the upper extremes, and niacin and riboflavin were the lower. Regarding breeding herd diets, vitamin concentrations were 2.9 times the 2012 NRC recommendations on average. In gestation diets, vitamins K and niacin were the upper extreme, and choline and biotin were the lower. Vitamins K and A were the upper extremes for lactation, and choline and biotin were the lower. The use of 25-Hydroxyvitamin D3 as a source of vitamin D has become more common compared with previous surveys. Its use was reported by 31% of the nutritionists in the nursery, 11% in the finishing, and 40% in gestation and lactation diets. Understanding current supplementation practices may help develop experimental designs to test different vitamin inclusions and provide an industry benchmark of vitamin usage.

The branched-chain amino acids (BCAA) Ile, Leu, and Val are 3 dietary essential amino acids for lactating sows; however, effects of dietary BCAA on sow and litter growth performance in the literature are equivocal. Thus, a meta-regression analysis was conducted to evaluate effects of BCAA and their interactions in lactating sow diets to predict litter growth performance, sow bodyweight (BW) change, and sow feed intake. Thirty-four publications representing 43 trials from 1997 to 2020 were used to develop a database that contained 167 observations. Diets for each trial were reformulated using NRC (2012) nutrient loading values in an Excel-based spreadsheet. Amino acids were expressed on a standardized ileal digestible (SID) basis. Regression model equations were developed with the MIXED procedure of SAS (Version 9.4, SAS Institute, Cary, NC), and studies were weighted by the inverse of the squared SEM. Statistically significant (P < 0.05) predictor variables were assessed with a step-wise manual forward selection and required to provide an improvement of at least 2 BIC for model inclusion. Significant predictor variables within 3 equations developed for litter ADG included the count of weaned pigs per litter, dietary concentrations of NE, SID Lys, and CP, sow ADFI, Val:Lys, Ile:Lys, and Leu:Val. For sow BW change, significant predictor variables within 2 developed models included litter size at 24 h, sow ADFI, Leu:Lys, and Ile+Val:Leu. The optimum equation for sow ADFI included Leu:Trp, SID Lys, NE, CP, and Leu:Lys as significant predictor variables. Overall, the prediction equations suggest that BCAA have an important role in litter growth, sow BW change, and feed intake during lactation; however, the influence of BCAA on these criteria is much smaller than that of other dietary components such as NE, SID Lys, sow ADFI, and CP.

A 45-d study used 340 weaned pigs (Line 241×600, DNA) to evaluate yeast additives in sow diets and yeast-based pre- and probiotics (Phileo by Lesaffre, Milwaukee, WI) in nursery diets on antimicrobial resistance (AMR) of fecal Escherichia coli. At weaning, pigs were penned based on sow diet and randomly assigned to 2 treatments with 5 pigs/pen and 17 pens/treatment. Treatments were a 2×2 factorial of sow treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc47HR+ and 0.025% SafMannan) and nursery treatment (control vs. yeast-based pre- and probiotic diet; 0.10% ActiSaf Sc47HR+, 0.05% SafMannan, and 0.05% NucleoSaf from d 0-7, then levels reduced 50% from d 7-24). A common diet was fed from d 24-45. Microbroth dilutions were used to determine minimum inhibitory concentrations (MIC) of E. coli isolates to 14 antimicrobials. A 3-way interaction of sow treatment×nursery treatment×sampling day was observed (P < 0.05) for ciprofloxacin, gentamicin, sulfisoxazole, and trimethoprim/sulfamethoxazole (Table 1). For ciprofloxacin, MIC was reduced (P = 0.044) on d 45 for the yeast-fed sow, yeast-fed nursery group compared with pigs from the yeast-fed sow, control-fed nursery group. The MIC values for the yeast-fed sow, yeast-fed nursery treatment were greater (P = 0.021) for gentamicin on d 5 but less (P = 0.018) than on d 24 compared with the yeast-fed sow, control-fed nursery treatment. On d 45, progeny of the control sows fed yeast in the nursery had less (P = 0.005) MIC to sulfisoxazole than control-fed sow, control-fed nursery treatment. Fecal E. coli had decreased (P = 0.004) MIC on d 5 to trimethoprim/sulfamethoxazole from the control-fed sow, yeast-fed nursery treatment compared with the control-fed sow, control-fed nursery treatment. All fecal E. coli isolates were susceptible to all antimicrobials except tetracycline on d 5. In conclusion, feeding sows live yeast and yeast extracts impacted fecal E. coli AMR in their progeny and this impact depends on nursery diet and post-weaning sampling day.

This experiment was conducted to evaluate the effect of balancing dietary cation-anion difference (DCAD), via added potassium bicarbonate (KHCO3), in diets containing low or high levels of L-Lys HCl on growth performance of growing-finishing pigs. A total of 1,944 pigs (PIC L337 × 1050, initially 35.2±0.85 kg) were used in a 120-d study. Pens of pigs were blocked by BW and randomly allotted to 1 of 4 dietary treatments in a randomized complete block design arranged in a 2×2 factorial with main effects of KHCO3 (0 vs 0.4%), and L-Lys HCl level (low vs. high), with 27 pigs/pen and 18 replicates/treatment. Diets were corn-soybean meal-based and formulated in 4 dietary phases (d 0-20, 30-58, 58-86, and 86-120). Diets were formulated in each phase such that the diet containing a low level of L-Lys HCl (0.14-0.21% depending on phase) without KHCO3, had similar calculated DCAD as the diet containing a high level of L-Lys HCl (0.36 to 0.43% depending on phase) with KHCO3. The DCAD for these 2 treatments were approximately 230, 200, 184, and 169 mEq/kg (phase 1, 2, 3, 4, respectively). The diets with low levels of L-Lys HCl with KHCO3 had the greatest DCAD in each phase (approximately 50 mEq/kg above the low L-Lys HCl without KHCO3 diet), while the diet with a high level of L-Lys HCl without KHCO3 had the least DCAD (approximately 50 mEq/kg below the high L-Lys HCl with KHCO3 diet). Overall, there was no evidence (P > 0.10) for a KHCO3 × L-Lys HCl interaction or main effect for any observed growth responses or carcass characteristics. The results of this study suggest that supplementing KHCO3 to finishing pig diets with either high or low levels of L-Lys HCl and the corresponding changes in DCAD values did not impact growth performance or carcass characteristics.

A total of 360 barrows (DNA Line 200×400; initially 6.1±0.05 kg) were used in a 38-d study to evaluate the effects of increasing levels of a modified corn protein product on nursery pig growth performance and fecal dry matter. Upon arrival to the nursery research facility, pigs were randomly assigned to pens (5 pigs/pen) and pens were randomly allotted to 6 dietary treatments (12 pens/treatment). Experimental diets were fed in 2 phases. Phase 1 (d 0-10) diets were formulated to contain 3, 6, 9, 12, or 15% of a modified corn protein or 6% enzymatically treated soybean meal (ESBM). Additions of the modified protein product and ESBM were reduced by 50% for phase 2 (d 10 to 25) diets and were: 1.5, 3.0, 4.5, 6.0, 7.5, and 3.0%, respectively. Nutrient loading values were provided by the supplier and diets were formulated to maximize L-Lysine HCl while keeping SID Lys:CP and SID AA:Lys similar across treatments. A common phase 3 diet was fed from d 25-38. During the experimental period (d 0-25), ADG (quadratic, P = 0.030) and ADFI (quadratic, P = 0.036) increased, and G:F worsened (linear, P = 0.006) as the amount of modified corn protein increased. For the overall experiment (d 0-38), ADG (quadratic, P = 0.028) and ADFI (quadratic, P = 0.032) increased then decreased and G:F tended to decrease (linear, P = 0.066) with increasing modified corn protein. There was a marginally significant treatment×day interaction (quadratic, P = 0.064) where fecal DM tended to increase (P = 0.051) on d 25 as the level of the modified corn protein was increased, but no evidence for change on d 10 (P > 0.10). These data suggest that the modified corn protein tested in this trial may be an alternative protein source to consider for nursery pig diets, when fed up to 12% in phase 1 and 6% in phase 2.

A total of 695 barrows (DNA 200×400; initially 5.9 ± 0.02 kg) were used in 2 groups in a 28-d study to evaluate the effects of dietary calcium carbonate level on nursery pig growth performance and fecal dry matter. Upon arrival to the research facility, pigs were randomly assigned to pens with 5 pigs/pen, and pens were allotted to 1 of 5 dietary treatments with 27 or 28 pens/treatment. Dietary treatments were formulated to provide 0, 0.45, 0.90, 1.35, and 1.80% calcium carbonate added at the expense of corn, which resulted in total Ca of 0.49, 0.66, 0.84, 1.01 and 1.18%, respectively. All diets were formulated to contain 0.68% total P and 0.59% STTD P. Diets were fed in 2 phases with treatment diets fed from d 0 to 14 and a common diet fed from d 14 to 28. Treatment diets were fed in meal (group 1) and pellet (group 2) form. Feces were collected from 3 pigs/pen and dried to calculate fecal dry matter. There was no evidence for a treatment×group interaction and thus, groups were combined. From d 0 to 14 (treatment period), ADG (P = 0.010), d 14 BW (P = 0.006), and G:F (P = 0.010) decreased linearly as calcium carbonate increased. There was no evidence for a difference in ADFI (P > 0.10) between treatments. For fecal dry matter, there was a tendency for a quadratic response (P = 0.091) with the highest and lowest calcium carbonate diets having the greatest dry matter. Subsequent performance from d 14 to 28 was not influenced by previous treatment (P > 0.10). In summary, increasing dietary calcium carbonate from 0 to 1.80% decreased ADG and G:F in pigs the first 14-d after weaning.

Two experiments were conducted to evaluate the effects of supplemental fat sources providing low and high essential fatty acids (EFA) in lactation diets on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. In Exp. 1, mixed parity sows (n = 91) were allotted to 5 experimental treatments arranged in a 2×2 + 1 factorial. Treatments were corn-soybean meal-based diets that contained no added fat or diets with 3% added fat as either beef tallow or soybean oil starting on d 107 or 112 of gestation. Sows were provided low EFA [linoleic acid (LA) and α-linolenic acid (ALA)] in diets without supplemental fat or with beef tallow or high EFA with soybean oil. Results confirmed that providing fat sources with high EFA can increase colostrum and milk LA and ALA content, regardless of pre-farrow time of diet consumption. However, supplemental fat did not influence litter growth performance (P > 0.05). In Exp. 2, mixed parity sows (n = 3,451) were assigned to 4 corn-soybean meal-wheat-based lactation diets with 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination) at d 112 of gestation to provide diets with low or high EFA. Lactation ADFI increased (P < 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. Sows fed Combination and SO diets had greater (P < 0.05) LA and ALA intake, LA and ALA in colostrum and milk, litter weaning weights, and litter ADG than sows fed 0.5 or 3% CWG. Sow EFA intake did not affect (P > 0.10) piglet survivability or subsequent sow reproductive performance. In conclusion, increased LA and ALA intake provided by SO during lactation increased overall litter growth and weaning weights but did not affect piglet survivability or subsequent performance.

A total of 360 pigs (Line 200 × 400, DNA, Columbus, NE, initially 9.9 ± 0.19 kg) were used in a 21-d growth study to determine the available P (aP) release curve for GraINzyme phytase (Agrivida Inc., Woburn, MA). Pigs were weaned at approximately 21-d of age, randomly allotted to pens based on initial body weight (BW) and fed common starter diets. From d 18 to 21 post-weaning, all pigs were fed a diet containing 0.11% aP. On d 21 post-weaning, considered d 0 of the study, pens were blocked by BW and randomly allotted to 1 of 8 dietary treatments with 5 pigs/pen and 9 pens/treatment. Dietary treatments were formulated to include increasing aP derived from either an inorganic P source (0.11, 0.19, or 0.27% from monocalcium P) or increasing phytase (150, 250, 500, 1,000, or 1,500 FTU/kg). Diets were corn-soybean meal-based and contained 1.24% standardized ileal digestible (SID) Lys. On d 21 of the trial, 1 pig/pen (weighing closest to the mean pen BW) was euthanized and the right fibula was collected to determine bone ash using the non-defatted processing method. Overall (d 0 to 21), pigs fed increasing aP from inorganic P or phytase had increased (linear, P < 0.002) ADG, ADFI, and G:F (quadratic, P < 0.05). Bone ash weight (g) and percentage bone ash increased (linear, P < 0.001) with increasing inorganic P or added phytase. The release equations developed for GraINzyme for ADG, G:F, bone ash weight, and percentage bone ash are: aP = (0.255 × FTU) ÷ (1,299.969 + FTU), aP = (0.233 × FTU) ÷ (1,236.428 + FTU), aP = (45,999.949 × FTU) ÷ (462,529,200 + FTU), and aP = (0.272 × FTU) ÷ (2,576.581 + FTU), respectively.

A total of 4,076 pigs (initially 39.3 kg) were used across 2 experiments to evaluate the effect of increasing ratios of Val, Ile, and Trp:Lys in corn-soybean meal-DDGS-based diets on pig growth performance and carcass characteristics. In both experiments, the 4 dietary treatments were: 1) high soybean meal and low feed grade amino acids (control), 2) low soybean meal and high feed grade amino acids, with Val:Lys, Ile:Lys, and Trp:Lys at 67, 55, and 18, respectively, (low ratio) 3) diet 2 except Val:Lys, Ile:Lys, and Trp:Lys increased to 72, 60, and 21, respectively, (medium ratio), and 4) diet 2 except Val:Lys, Ile:Lys, and Trp:Lys at 80, 65, and 23, respectively (high ratio). The Leu:lys levels for the diets with increased synthetic amino acids ranged from 135 to 146 for the 4 phases. All diets contained 30% DDGS until 100 kg BW, and then 20% DDGS until trial completion. Because there was no experiment × treatment interactions, data from both experiments were combined. Overall, ADG and ADFI increased (AA ratio; linear, P < 0.05) as Val, Ile, and Trp:Lys ratios increased from low to high. Pigs fed the control diet exhibited increased ADG compared with pigs fed low ratio diets, while pigs fed medium and high ratio diets performed intermediate. For carcass characteristics, pigs fed the control had increased (P < 0.05) percentage lean and loin depth compared with pigs fed the medium ratio diet, with pigs fed low and high ratio intermediate. Pigs fed the medium ratio diet had increased backfat depth compared with pigs fed the control, with pigs fed the low and high ratio intermediate (P < 0.05). In summary, the soybean meal level can be reduced, and synthetic amino acid levels increased in high DDGS diets as long as ratios of Val, Ile, and Trp to Lys are increased.

A total of 1,080 mixed sex growing-finishing pigs (337 × 1050, PIC; initially 28.7 ±0.39 kg) were used in a 123-d growth trial to determine the effects of vitamin concentrations on finishing pig growth performance and carcass characteristics. Pens of pigs were assigned to 1 of 2 treatments in a completely randomized design. There were 20 replicate pens/treatment and 27 pigs/pen. The experimental diets were corn-soybean meal-based and were fed in 4 phases from 28 to 50, 50 to 73, 73 to 100 and 100 to 133 kg. Pigs were fed 1 of 2 levels of a vitamin premix (control and high) that contained: 1,653,468 IU vitamin A acetate; 661,387 IU vitamin D, vitamin E (17,637 mg dl-α-tocopheryl acetate), 1,323 mg vitamin K (menadione), 13.2 mg vitamin B₁₂, 19,842 mg niacin, 11,023 mg pantothenic acid, and 3,307 mg riboflavin per kg. The amount per phase was 1.36, 1.13, 0.91 and 0.07%, respectively, for the control with the added amount doubled for the high vitamin fortification. Overall, (day 0 to 123), there was no evidence for difference (P > 0.10) in ADG, ADFI and G:F. Also, no statistical difference was found (P > 0.10) for final BW, HCW or any carcass characteristic. In conclusion, the level of vitamins used in this study did not influence growth and carcass traits in finishing pigs.

Two experiments were conducted to determine the impact of diets with yeast-based direct fed microbials (DFM) in nursery pigs weaned from sows fed lactation diets with or without yeast additives. Treatment descriptions for both experiments are reviewed in Table 1. There was no evidence of sow and nursery treatment interactions for either experiment (P > 0.05). In Exp. 1, 340 weaned pigs, initially 5.1 kg ± 0.02, were used to evaluate previous sow treatment (control vs yeast additives; Phileo by Lesaffre, Milwaukee, WI) and nursery diets with or without DFM. Treatments were a 2×2 factorial with main effects of sow treatment and nursery treatment (control vs. yeast-based pre- and probiotic diet) with 5 pigs/pen and 17 replications/treatment. Progeny from sows fed yeast additives had increased (P < 0.05) ADG from d 0-24 and d 0-45. However, pigs that were fed yeast additives for the first 24 d in the nursery tended to have decreased d 0-45 ADG (P = 0.079). In Exp. 2, 330 weaned pigs, initially 5.8 kg ± 0.03, were used to evaluate diets with combinations of DFM. Treatments were arranged in a 2×3 with main effects of sow (same as Exp. 1) and nursery treatment with 6 pigs/pen and 8 to 10 replications/treatment. From d 0-10 post-weaning, progeny of sows fed yeast additives had increased (P < 0.05) ADG and G:F. From d 24-38 when pigs were fed common diets with no added yeast-based products, ADG for pigs previously fed DFM2 was greater (P < 0.05) than control. In conclusion, feeding sows yeast during lactation improved offspring nursery growth performance in both studies. Interestingly, feeding live yeast and yeast extracts reduced nursery pig performance in Exp. 1; however, feeding DFM 2 improved growth later in the nursery in Exp. 2.

A total of 988 nursery pigs were used to determine the effect of body weight, body temperature, and blood glucose on the survivability of pull pigs after removal. At weaning, pigs were transported to a 24,000 head hotel-style nursery and placed in rooms based on sow source. Over a 4-week period post-placement, every other pig removed from the general population for welfare considerations (lameness, sick, or fallback) were tagged, weighed, and their body temperature and blood glucose measured. Mortality was tracked through the end of the nursery or approximately 38 d post-placement. Data were analyzed as a completely randomized design with room as a random effect. The predictor variables of body weight, body temperature, and blood glucose were categorized into biologically significant categories and LSMeans were determined using a binary model with mortality as the outcome. Pigs with a body weight under 4.5 kg at removal had increased mortality rate (32.4%; P< 0.001) compared with pigs with a body weight between 4.5 and 5.4 kg (20.8%) or greater than 5.4 kg (14.6%) at removal. Pigs with a body temperature below 38.6°C or above 39.7°C at removal had increased mortality rate (33.4 or 26.8%, respectively; P < 0.001) compared with pigs with a body temperature between 38.6 and 39.7°C (17.7%) at removal. Pigs with a blood glucose greater than 120 mg/dL at removal had increased mortality rate (43.5%; P < 0.001) compared with pigs with a blood glucose less than 70 mg/dL (23.0%) or between 70 and 120 (17.9%) at removal. In summary, pull pigs with low bodyweight, high or low body temperature, or high blood glucose had decreased survivability. The results of this study indicate that there are metabolic differences between nursery pigs at the time of removal and that these differences may influence survivability.

A total of 2,160 pigs (PIC 337×1050; initial BW 35.1 kg) were used in a 112-d growth trial to evaluate the effects of normal or high SID Thr:Lys ratio in diets with and without DDGS on growth performance. Pigs were assigned to pens (27 pigs per pen) in a randomized complete block design by BW with 20 replications per treatment. Pens of pigs were allotted to 1 of 4 dietary treatments arranged in a 2×2 factorial with main effects of dietary Thr level (Normal vs High) and DDGS (with or without). Treatment diets were formulated in 4 phases from 35 to 57, 57 to 82, 82 to 105, and 105 to 136 kg BW. Diets with high DDGS were formulated to include 40% DDGS in phase 1 and 2, 30% in phase 3, and 15% in phase 4. Normal Thr diets were formulated to contain 61, 62, 63, and 65% SID Thr:Lys ratios for the 4 dietary phases, respectively. High Thr diets had SID Thr:Lys ratios of 67, 68, 69 and 72%, respectively. There were no (P>0.10) DDGS×Thr interactions. For the overall period (d 0 to 112), pigs fed diets without DDGS had increased (P < 0.001) ADG and BW, and reduced (P < 0.001) ADFI leading to improved (P < 0.001) G:F. There was no evidence for difference (P > 0.10) between diets with normal or high SID Thr:Lys ratio regardless of DDGS inclusion. In summary, the addition of high levels of DDGS reduced ADG and increased ADFI, which resulted in poorer G:F and lighter final BW, regardless of the dietary SID Thr:Lys ratio. These results indicate that addition of an insoluble fiber source, such as corn DDGS, does not increase the Thr:Lys requirement of finishing pigs.

Two experiments were conducted using 48 litters and 711 nursery pigs to determine the effect of a powder sensory attractant (Exp. 1; Baby Pig Restart APF; TechMix Global; Stewart, MN) or enrichment cube (Exp. 2; supersized pellets resembling cattle cubes) pre- and post-weaning on feed intake and growth. Treatments were arranged in a 2x2x2 factorial with main effects of pre-weaning treatment (without/with attractant), post-weaning treatment (without/with attractant), and BW category (light/heavy). Pre-weaning treatments were assigned in a RCBD and post-weaning treatments were assigned in a CRD. Litters receiving attractant pre-weaning were provided 90 g/d of powder, divided into 2 feedings, in the pan of rotary creep feeders (Exp. 1) or 100 g of cubes once daily on the floor of farrowing stalls (Exp. 2) for 4-d prior to weaning. After weaning, pens of pigs that received attractant were offered 45 g/d of powder, divided into 2 feedings/d for 2-d (Exp. 1), or 100 g of cubes once daily (Exp. 2) top-dressed on feed in the feeder pan for 3-d post-weaning. In both experiments, pre- and post-weaning attractant had limited effects on the growth performance of pigs after weaning. In Exp. 1, the percentage of pigs that lost weight 3-d post-weaning decreased by approximately 20 percentage points when pigs were provided powder both pre- and post-weaning compared with the other 3 treatment combinations (P = 0.015). No differences were observed for BW category. In Exp. 2, the percentage of pigs that lost weight 7-d post-weaning decreased by 11.7 percentage points when pigs were offered cubes compared with no cubes (P = 0.002). On d 3, more heavyweight pigs lost weight (P = 0.007) than lightweight pigs; however, this effect was diminished by d 7. In summary, sensory attractants reduced the percentage of pigs that lost weight immediately after weaning which may be due to encouraged activity around the feeder.

A total of 360 pigs (initially 5.7±0.2 kg) were used to determine the effect of pharmacological levels of Zn and dietary Na concentration on nursey pig growth performance. The experiment compared NRC (2012) and European CVB (2020) Na estimates for this weight range (0.35% and 0.24%, respectively), with or without added Zn from ZnO. At weaning, pigs were randomly allotted to pens (6 pigs/pen) and fed a common diet for 7 d. On d-7 after weaning (d-0 of trial), pigs were assigned to 6 dietary treatments with 10 replications/treatment. Dietary treatments were arranged in a 2×3 factorial with main effects of Zn (0 or 2,000 ppm from ZnO) and Na (0.13, 0.24, or 0.35% from salt). All diets contained 110 ppm of Zn from the trace mineral premix. Following a 14-d experimental period, pigs were fed a common phase 3 diet for 21-d. There were no Zn×Na interactions for ADG or ADFI (P >0.05). From d 0-14, adding dietary ZnO or increasing Na increased (linear, P < 0.05) ADG and ADFI. An interaction for G:F (linear, P = 0.019) was observed where increasing Na up to 0.35% improved G:F when pharmacological levels of Zn were fed, but pigs fed diets without ZnO had a quadratic response (P =0.024) with maximum G:F at 0.24% dietary Na. From d 14-35 and overall, an interaction was observed (linear, P < 0.05) for G:F. Within the interaction, pigs previously fed diets without ZnO observed a linear decrease in G:F as Na level increased (linear, P =0.001), but pigs previously fed diets with ZnO observed no difference in G:F with increasing Na. In summary, increasing dietary Na and the addition of 2,000 ppm Zn from ZnO independently improved daily gain and feed intake in nursery pigs, but an improvement in G:F from increasing Na up to 0.35% was only observed when pharmacological ZnO was present.

Two experiments were conducted to determine if fermented corn protein (FCP) can serve as a replacement to enzymatically treated soybean meal (ESBM) in 6.0 to 15.8 kg or as a replacement for soybean meal in 12.1 to 24.7 kg pig nursery diets. In Exp. 1, 350 barrows (initially 6.0 kg) were randomly allotted to 5 treatments with 5 pigs/pen and 14 replications/treatment. Dietary treatments were arranged in a 2×2 + 1 factorial with a control diet or diets with 5 or 10% FCP or ESBM. Newly weaned pigs were fed phase 1 diets for 10-d followed by phase 2 diets for 21-d. There were no interactions throughout the experiment. Overall (d 0-31), pigs fed increasing FCP had decreased (linear, P ≤ 0.026) ADG and ADFI with no differences in G:F, whereas increasing ESBM had no effect on growth performance (Table). Pigs fed ESBM had increased (P ≤ 0.034) ADG and G:F compared with pigs fed FCP with no effect on ADFI. In Exp 2, 350 pigs (initially 12.1 kg) were randomly assigned to pens with 5 pigs/pen and 14 replications/treatment. On d 24 after weaning (d 0 of trial), pens of pigs were weighed and assigned to 5 dietary treatments. Dietary treatments were arranged in a 2×2 + 1 factorial with a control diet or diets with 10 or 20% FCP with either high or low Val+Ile:Leu ratios. There were no interactions observed throughout the experiment. Overall (d 0-21), ADG, ADFI, and G:F worsened (linear, P < 0.001) as FCP increased. High Val+Ile:Leu ratios improved (P = 0.017) G:F compared with low Val+Ile:Leu ratios with no effect on ADG and ADFI. In summary, using FCP to replace ESBM for nursery pigs weighing 6.0 to 15.8 kg had decreased growth performance. Increasing concentrations of FCP in diets for pigs weighting 12.1 to 24.7 kg worsened growth and increasing Val+Ile:Leu ratios only improved G:F.

The COVID-19 global pandemic greatly affected pork processing plants in the United States. These pork processing plants were forced to either temporarily close or operate at reduced capacity due to the increased number of health-related employee absences. Because finishing pigs could not be timely marketed, methods to reduce growth performance were required to keep pigs from becoming too heavy at slaughter weight. Therefore, our objective was to determine the extent that reducing dietary standardized ileal digestible (SID) Lys and tryptophan-to-lysine ratio (Trp:Lys) ratio would slow finishing pig average daily gain (ADG) in a commercial setting. A total of 1,080 finishing pigs (327 × 1050, PIC; initially 32.3 kg) were used in a 119-d growth trial. Pigs were allotted by initial body weight (BW) and randomly assigned to 1 of 4 dietary treatments in a completely randomized block design with 27 pigs per pen and 10 pens per treatment. Three dietary regimes were formulated to contain either 100%, 90%, or 80% of the estimated SID Lys requirement for pigs in this facility, with a SID Trp:Lys ratio of 19%, with the exception of the last dietary phase formulated to 17% SID Trp:Lys. Seven different dietary phases were fed. The SID Lys concentrations in the 100% diets were: 1.10%, 1.01%, 0.91%, 0.83%, 0.79%, 0.71%, or 0.67% SID Lys from 32 to 40, 40 to 51, 51 to 72, 72 to 85, 85 to 98, 98 to 112, and 112 to 130 kg, respectively. A fourth regime was formulated to 80% SID Lys with a SID Trp:Lys ratio of 16% (80–16% SID Trp:Lys) throughout all phases. Overall from d 0 to 119, ADG (linear, P < 0.001), final BW (linear, P < 0.001), and gain-to-feed (G:F) decreased (linear, P = 0.087) as SID Lys decreased from 100% to 80% of the estimated requirement. Pigs fed the 80–16% SID Trp:Lys diets had an additional decrease in ADG (P < 0.05) and G:F (P < 0.10) compared with pigs fed 80% of the SID Lys requirement with the normal Trp:Lys ratio. The reduction in SID Lys (from 100% to 80%) and reduction in SID Lys and Trp:Lys ratio resulted in an 8.6 and 11.7 kg, respectively, decrease in final BW compared with pigs fed Lys and Trp at the requirement (100%). This study provides alternatives for pork producers to reduce growth rate of finishing pigs.

In the United States, emphasis has shifted toward improved pork quality and has resulted in greater use of Duroc-based terminal sires. Duroc sires have differences in ADG, ADFI, G:F, and carcass leanness compared to other sires. Therefore, our objective was to determine the standardized ileal digestible (SID) Lys estimates for Duroc-based sired finishing pigs. In Exp. 1, 2,124 pigs (DNA 600 ×PIC 1050, initially 48.9 kg) were used with 24–27 pigs per pen and 16 pens per treatment. Corn-soybean meal-based diets were fed in three phases (49–59, 59–71, and 71–81 kg). Pens were randomly allotted to 1 of 5 treatments based as a percentage of PIC (2016) SID Lys estimates for gilts (85%, 95%, 103%, 110%, and 120%). Phase 1 diets were formulated to 0.90%, 1.01%, 1.09%, 1.17%, and 1.27%, phase 2 to 0.79%, 0.87%, 0.94%, 1.03%, and 1.10%, and phase 3 to 0.71%, 0.78%, 0.85%, 0.92%, and 0.99% SID Lys. Increasing SID Lys increased (linear, P < 0.001) ADG and Lys intake/kg of gain. A marginally significant improvement (quadratic, P = 0.071) in G:F was observed as SID Lys increased. Feed cost, feed cost/kg of gain, revenue (linear, P < 0.01) and income over feed cost (IOFC) increased (quadratic, P = 0.045) with increasing SID Lys. In Exp. 2, 2,099 pigs (DNA 600 ×PIC 1050, initially 90.1 kg) were used with 24–27 pigs per pen and 20 pens per treatment. Corn-soybean meal-based diets were fed in 2 phases (90–106 and 106–136 kg). Pens were randomly allotted to 1 of 4 treatments based as a percentage of PIC (2016) SID Lys estimates for gilts (85%, 93%, 100%, and 110%). Phase 1 diets were formulated to 0.65%, 0.71%, 0.77%, and 0.84% and phase 2 to 0.60%, 0.66%, 0.71%, and 0.78% SID Lys. Overall, increasing SID Lys increased (linear, P < 0.05) G:F, Lys intake/kg of gain, live weight and HCW, and increased (quadratic, P = 0.020) ADG. Feed cost (linear, P < 0.01), revenue, and IOFC increased (quadratic, P ≤ 0.053) with increasing SID Lys. In conclusion, the SID Lys estimate for growth and IOFC was 1.19% or 4.63 g SID Lys/Mcal of NE, 1.05% or 4.04 g SID Lys/Mcal of NE, and 0.94% or 3.58 g SID Lys/Mcal of NE for pigs weighing 49–59 kg, 59–71 kg, and 71–81 kg, respectively. The SID Lys estimate for late finishing pigs was 0.74%–0.81% or 2.85–3.10 g SID Lys/Mcal of NE, and 0.69%–0.75% or 2.61–2.84 g SID Lys/Mcal of NE, for 90–106 kg and 106–136 kg pigs, respectively. These data provide SID Lys estimates for current Duroc-sired genetic lines raised in a commercial environment.

Methods for developing incoming replacement gilts can indirectly and directly influence survivability of their offspring. Indirectly, having proper gilt development reduces culling rates and mortality, which increases longevity and creates a more mature sow herd. Older sows are more likely to have greater immunity than gilts and therefore can pass this along to their pigs in both quantity and quality of colostrum and milk, thus improving piglet survivability. Directly, proper gilt development will maximize mammary gland development which increases colostrum and milk production leading to large, healthy pig. As for the developing gilt at birth, increasing colostrum intake, reducing nursing pressure, providing adequate space allowance, and good growth rate can increase the likelihood that gilts successfully enter and remain in the herd. Light birth weight gilts (1 kg) or gilts from litters with low birth weight should be removed early in the selection process. Gilts should be weaned at 24 d of age or older and then can be grown in a variety of ways as long as lifetime growth rate is over 600 g/d. Current genetic lines with exceptional growth rate run the risk of being bred too heavy, reducing longevity. On the other hand, restricting feed intake at specific times could be detrimental to mammary development. In these situations, reducing diet amino acid concentration and allowing ad libitum feed is a possible strategy. Gilts should be bred between 135 and 160 kg and at second estrus or later while in a positive metabolic state to increase lifetime productivity and longevity in the herd. Once bred, gilts should be fed to maintain or build body reserves without becoming over-conditioned at farrowing. Proper body condition at farrowing impacts the percentage of pigs born alive as well as colostrum and milk production, and consequently, offspring performance and survivability. Combined with the benefit in pig immunity conferred by an older sow parity structure, gilt development has lasting impacts on offspring performance and survivability.Proper gilt development influences offspring performance and survivability by increasing gilt longevity and colostrum and milk production. Gilt development success starts in selecting gilts heavier than 1 kg at birth, prioritizing colostrum and milk intake, and weaning at 24 d of age or older. During the grower phase, attention must rely on nutrition and feeding management to avoid fat gilts at farrowing, promote adequate mammary development, and have structural soundness. Appropriate boar exposure and reaching target weight (135 to 160 kg) at breeding in the second or third estrous can dictate reproductive performance and longevity. During gestation, the whole focus is on body condition. Fat gestating gilts may struggle with leg and feet issues and compromise the litter due to lower colostrum and milk production. Properly developed gilts directly impact livability of their offspring through increased colostrum and milk production. Increased longevity indirectly improves livability because offspring of older sows have improved growth and survival rate compared to offspring of first litter sows.