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The objective of this study was to assess if high dietary zinc (Zn) fed to gestating sows modulates the microbiome of the sow and that of their offspring. Sows were fed 1 of 3 dietary treatments: 1) Control: a corn-soybean meal-based diet containing 125 ppm total supplemental zinc, 2) Breed-to-Farrow: as Control + 141 ppm supplemental Zn as ZnSO4fed from 5 d post-breeding to farrowing; and 3) Day 110-to-Farrow: as Control + 2,715 ppm supplemental Zn as ZnSO4starting on d 110 of gestation until farrowing. A subset of third parity sows (n = 30; 10 per treatment) were selected to assess the microbiome of colostrum, milk, and rectal and vaginal surfaces of sows. At farrowing, 4 pigs per litter (n = 120) were selected based on birthweight (BiW; 2 average BiW pigs and 2 pigs with BiW below the litter average) were selected to assess the piglet gut microbiome on the day of birth (d 0) and d5 of age. 16S rRNA sequencing was implemented for colostrum and milk samples while all other sample types were sequenced using shotgun metagenomics to determine taxonomic and functional profiles. Measures of alpha and beta diversity were conducted along with determination of differentially abundant taxa and pathways in tandem with generalized linear mixed models. Greater dietary concentrations of Zn fed to gestating sows minimally affected their colostrum, milk, and vaginal microbiome. However, fecal samples of Breed-to-Farrow sows showed decreased abundance of potentially pathogenic bacteria such as Salmonella entericaand Shigella flexneriand greater abundance of bacteria typically involved in fiber fermentation compared with Control sows (Figure 1a). Piglets born to Day 110-to-Farrow sows also showed greater abundance of some taxa typically involved in fiber breakdown and short chain fatty acid (SCFA) generation on d 5 compared with Control pigs (Figure 1b). At d 0, Breed-to-Farrow piglets showed less abundance of methanogenic archaea and differential abundance of taxa with potentially pathogenic roles, compared with Control pigs (Figure 1c). Gene families and pathways playing roles in central metabolic functions (starch, pyruvate, sucrose, amino acid metabolism) were more abundant in Breed-to-Farrow piglets compared with pigs born to Control sows on d 0 and 5 of age. In conclusion, greater Zn fed to gestating sows impacted the abundance of gut taxa with potential roles in SCFA-production and pathogenicity in both sow and piglet, despite overall minor effects. However, the physiological significance of these findings for the sow and piglet remains unclear.

This study aimed to evaluate effects of Aspergillus oryzaepostbiotic (AOP) supplementation in gestation and lactation diets on sow performance, litter performance, and offspring performance through the nursery period. Sows [n = 118; Landrace × Yorkshire; body weight (BW) = 238 ± 2.2 kg; parit y= 3.8 ± 0.32] were blocked by parity and assigned randomly to one of two treatments. Treatments were a control diet and a control diet supplemented with AOP (Biozyme Inc.) at 1.5 g/sow/d in gestation from 5 days before breeding until farrowing, and adjusted to 1.55 g•sow-1•d-1during lactation. Sow BW and P2 backfat thickness were measured on d 0, 30, and 109 of gestation and 24 h postpartum and at weaning on d 20 ± 2. Litters were standardized to 13 piglets within 24 h of farrowing. Piglets were weighed individually at birth, after 24 h, and at weaning. At weaning, 369 pigs were allotted to pens within maternal dietary treatment (48 pens, with 7 or 8 pigs/pen) for a 42-d nursery trial. All pigs received a common nursery diet in 3 dietary phases. Sows fed AOP had a lighter (P < 0.01) BW than those in the control group on d 109 of gestation (234.1 vs 244.1 kg) and post-farrowing (227.4 vs 236.7 kg), respectively, but not at other time points. Moreover, sows fed AOP showed less (P< 0.01) BW loss from d 109 of gestation to weaning (-0.9 vs -7.8 kg) and from post-farrowing to weaning (4.1 vs -1.9 kg) compared with control sows. Total feed intake and average daily feed intake (Control: 6.0 vs AOP: 6.2 kg/d) during lactation were not impacted (P> 0.10) by dietary treatments. Supplementation of AOP did not influence (P> 0.10) litter size (14.8 vs 16.0), litter birth weight (17.4 vs 18.2 kg), percentage of low birth weight piglets (13 vs 12.5 %) or normal birth weight piglets (87.0 vs 87.5 %), stillbirths (1.2 vs 1.2/litter), or mummies (0.9 vs 0.5/litter) for Control and AOP sows, respectively. Across treatments, no differences (P> 0.10) were observed for litter weight gain (43.2 vs 40.4 kg), average piglet BW at weaning (5.1 vs 4.9 kg), or piglet mortality rate (12.4 vs 13.1 %) for Control and AOP sows, respectively. Piglets weaned from AOP sows tended (P= 0.07) to have an increased average daily feed intake (ADFI) during the first week after weaning compared with pigs weaned from Control sows (0.28 vs 0.26 kg), but AOP did not influence other performance parameters for the entire nursery period. There were no interactions between maternal dietary treatment and nursery phase (P> 0.10), suggesting consistent responses to maternal dietary treatments over time. In summary, feeding sows AOP reduced sow BW loss but had no impact on litter or nursery performance.

Various types of soybean co-products are used in swine diets which have benefits and limitations related to protein quality, environmental impact, and feed safety. To address these concerns for sustainable pork production, methodologies have evolved. Soybean processing and storage methods affecting protein oxidation have been studied less than lipid oxidation. Protein carbonyl concentrations were measured and compared among diverse samples of soybeans and soybean meal from different regions of the US and processed by mechanical or solvent extraction. Mechanically extracted soybean meal had greater concentrations of protein carbonyls than solvent extracted soybean meal which were associated with a greater concentration of residual oil. Soybeans and their co-products also contain antioxidants that may protect against more extensive lipid and protein oxidation. Understanding the interactions between natural antioxidants and oxidation of lipid and proteins in soy co-products is important for optimizing nutritional efficiency and health in sustainable pork production systems. Because soybean meal is a major component of swine diets, its origin and environmental footprint affects the environmental impact of feed, manure, and pork production. Using a spatially explicit lifecycle assessment of feed ingredients and regional manure management programs, we compared the effect of using four feeding programs on greenhouse gas (GHG) emissions, land use, and embedded water consumption in 3 major U.S. pork production regions assuming they would provide equal growth performance and carcass composition. Although environmental impacts varied among regions, the corn-soybean meal feeding program resulted in the greatest land and water use of all grower-finisher feeding programs, and more GHG emissions than feeding low protein amino acid supplemented (LP) diets and diets containing 8% supermarket food waste, but less overall GHG emissions than the distiller’s dried grains with solubles (DDGS) feeding program. Results from a subsequent study showed that feeding corn-soybean meal diets optimized growth performance and carcass composition while simultaneously reducing impacts on climate change, marine and freshwater eutrophication, and fossil resource use compared with feeding DDGS and LP diets. Lastly, the extended survival of infectious agents such as African swine fever virus in feed ingredients has important implications for biosecurity and prevention of transboundary transmission of swine diseases. We developed a risk-free in situ surrogate non-animal assay (RISNA) to estimate survival of ASFV in various feed ingredients and conditions, and results indicate greater thermal stability than previously observed, and comparable extended survival among corn- and soybean-based ingredients. These new insights will be useful in revising feed biosecurity protocols to prevent introduction and transmission of ASFV in feed supply chains. In conclusion, holistic assessments of feed ingredients, like our evaluation of soybean co-products, are needed to achieve a more sustainable, One Health approach to pork production.

The objective of this study was to assess impacts of dietary zinc (Zn) supplementation strategy on immune response, bacterial clearance, and disease severity in growing gilts infected with Mycoplasma hyopneumoniae. Weaned gilts [n = 96; 21-d old; initial body weight (BW) = 6.94 kg], were used in a 63-d experiment which consisted of a pre- (d 0-35) and post- (d 35-63) M. hyopneumoniaechallenge. On d 0 (-35 d post-inoculation; dpi), gilts were confirmed negative for M. hyopneumoniaeand PRRSv and assigned randomly to 1 of 2 dietary treatments with 8 pens/treatment and 6 gilts/pen. Treatments were: 1) Control; 125 mg/kg Zn from ZnSO4, and 2) Zn-blend; 125 mg/kg Zn with 50 mg/kg Zn from Zn-amino acid complex (ZnAA) and 75 mg/kg Zn from ZnSO4. Dietary treatments were fed in 4-phases with pharmacological levels of zinc oxide included in the first 2 phases. Phase 1 (d 0) control and Zn-blend diets contained 3,121 and 3,256 mg/kg total Zn, respectively. Phase 2 (d 0-14) control and Zn-blend diets contained 3,657 and 3,593 mg/kg total Zn, respectively. Phases 3 (d 14-35) and 4 (d 35-63) control and Zn-blend diets contained 213 and 193 mg/kg and 229 and 212 mg/kg total Zn, respectively. At 0 and 1 dpi, all gilts were inoculated intratracheally with 10 mL of a lung homogenate containing 1×105CCU/mL of M. hyopneumoniaestrain 232. Blood and tracheal secretions were collected on -35, 0, 7, 14, 21, 28 dpi. Blood samples were evaluated for antibody detection, and tracheal secretions were analyzed by PCR. Number of coughs were recorded daily from 7 to 28 dpi. At 28 dpi, gilts were humanely euthanized, and bronchoalveolar lavage fluid (BALF) and macroscopic lung lesion observations were collected. Gross lung lesions were scored, and lung tissues were fixed for histopathology. Normally distributed data were analyzed in a generalized linear model with the fixed effect of diet and repeated measures for days post-inoculation. Non-normal data were analyzed using a Mann Whitney U Test using the NPAR1WAY procedure of SAS with a fixed effect of diet or a Chi-square test. Gilts consuming control diets tended (21.68 vs. 20.90 Ct, P= 0.08) to have less relative bacterial load than those consuming Zn-blend diets, over time. No differences in mean sample-to-positive ratio or proportion of gilt seroconversion (P> 0.05) were detected between treatments. There were no differences in mean concentrations of IL-1α, IL-1β, IL-6, IL-8, IL-10 (P> 0.05) in BALF for gilts consuming control or Zn-blend diets. There were no differences in mean macroscopic (P= 0.73) or microscopic (P= 0.67) lung scores, and coughing index score (P= 0.25) over the entire period between gilts consuming the different dietary Zn supplementation strategies. In conclusion, growing gilts consuming diets containing different Zn sources exhibited similar signs of infection during the acute phase of a M. hyopneumoniaeinfection.

African swine fever virus (ASFV) is a member of the nucleocytoplasmic large DNA viruses (NCLDVs) and remains stable in a variety of environments, including animal feed ingredients as shown in previous laboratory experiments and simulations. Emiliania huxleyivirus (EhV) is another member of NCLDV, which has a restricted host range limited to a species of marine algae called Emiliania huxleyi. This algal NCLDV has many similar morphological and physical characteristics to ASFV which makes it a safe and reliable surrogate for studying ASFV survival and inactivation in feed ingredient matrices in-situ under various time and temperature storage conditions. The objective of the present study was to investigate the inactivation of ASFV in various feedstuffs under a wide range of time and temperature conditions during storage using EhV as a surrogate. Corn- and soybean-based feed ingredients including corn, corn fermented protein, distiller dried grains with solubles, extruded soybean meal, high protein distiller’s grains, solvent-extracted soybean meal, soybean hulls, complete feed, and a positive control (no matrix) were inoculated with EhV (1 × 108viruses/mL). Negative controls were inoculated with medium containing no EhV for each matrix. To assess the effects of different times and temperatures of storage, all samples were stored at temperatures of 4, 24, and 34 °C for 1, 5, 60, and 120 d. For each timepoint and temperature combination, samples were evaluated for virus presence (qPCR) and viability using a previously validated viability qPCR (v-qPCR) method. On average, we observed a 0.2 log reduction in viable viral DNA content over the 120-d period, with a 0.1 log reduction across varying temperatures. No reductions in EhV viability exceeding 1 log were detected for any matrix and the positive control at any time and temperature combination evaluated. No EhV was recovered from the negative control samples. Given that the experimental error was calculated to be within the range of 1 log, we concluded that storing EhV at 4, 24, or 34 °C for up to 120 d did not result in the inactivation of EhV in any of the ingredients, complete feed, or the control with no matrix. These results demonstrate that ASFV-like NCLDVs is extremely resilient and can maintain viability in various feed matrices during long-term storage and suggest that extending storage time alone may not be an effective mitigation practice against African swine fever virus.

The objective of this study was to determine the effect of replacing feed-grade zinc oxide (ZnO) with decreased contents of an activated zinc oxide (aZnO) on growth performance of weaned pigs. A total of 720 pigs (Landrace × Yorkshire × Duroc; TOPICS, Richfield, MN) with an initial body weight (BW) of 5.88 ± 0.97 kg were distributed into 60 pens with 12 pigs per pen following a randomized complete block design. After weaning at 18 d of age, pigs were fed one of five diets differing in ZnO source and Zn content during a 3-phase feeding program for 42 d (Table 1). Experimental diets were formulated to meet minimum nutrient requirements. Mortality was monitored daily and analyzed using survival analysis. Performance data were analyzed by multiple linear regression, with BW gain as dependent variable and Zn source (ZnO, aZnO) and Zn content as the independent variables for each phase. Linear regression analysis used diet A as baseline (150 ppm ZnO). In addition, groups receiving diet E and B, both supplemented with the same ZnO level during phase-1, were compared using a t-test. A linear relationship was observed between BW gain and dietary Zn content (P< 0.001) and Zn source (P= 0.026). A slope ratio between the two Zn sources indicated that pigs provided with aZnO had a 72% greater growth rate compared with ZnO. In addition, during Phase 1, when both diets B and E offered similar Zn concentrations (1,200 ppm) as ZnO and aZnO, pigs fed aZnO outperformed ZnO-fed pigs by 490 g (P< 0.001). The mortality was 7.6% less (P= 0.009) for diet C than diet A. No differences were detected among pigs fed the test diets in Phases 1, 2 and 3 for other variables. In conclusion, results show the potential of aZnO as a suitable replacement for ZnO, but also underscore the effect of dietary Zn content on pig performance and mortality. The aZnO source is a suitable replacement for ZnO, enhancing growth performance in weaned pigs and demonstrating potential for reducing overall Zn usage, thereby mitigating the environmental impact of swine production.

A previous experiment was conducted to determine if cleanliness of a water delivery system influenced growth performance of nursery pigs. Additionally, we hypothesized that cleanliness of the water delivery system would alter populations of intestinal bacteria. Newly weaned pigs (n = 315; about 21 d of age) were used in a 42-d experiment and were assigned randomly to 1 of 2 water line treatments with 17 to 18 pens/treatment and 9 pigs/pen. Treatments consisted of water delivered to pens via a water distribution system in use for 21 years without cleaning (OLD) or water delivered to pens via a water distribution system in use for 6 weeks (NEW). Water for both distribution systems was sourced from a common well. Pigs were housed in an environmentally controlled, power-ventilated, confinement nursery barn and were allowed ad libitum access to water and common diets fed in 3 phases across OLD and NEW treatments. Twenty-eight pigs of average body weight (n = 14 pigs/treatment) were selected for collection of fecal swabs on days 0, 4, and 42 post-weaning. A pooled water sample was collected from 10 randomly selected pens/treatment and from the water supply on days 4 and 42. Swabs were also collected from the inside surface of each water line at the beginning and end of each line. To characterize the microbiome in all samples, extracted DNA was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 and various packages within the R statistical software. Bacterial community composition of water and water line samples differed between OLD and NEW, while the sampling location of line swabs differed by location (PERMANOVA, R2= 0.2-0.6, P< 0.05). No differences in alpha diversity were observed in pig fecal bacteria at d 0 or d 42 between OLD and NEW line. However, at d 4, pigs drinking water from the NEW line had increased fecal bacterial richness (P = 0.044) and a tendency for increased bacterial diversity (Shannon’s H, P = 0.059) compared with pigs drinking water from the OLD line. There were no differences in bacterial community composition between the OLD and NEW line throughout the trial; however, pigs drinking water from the NEW line showed more discriminating bacterial taxa compared with OLD at day 4 and 42, including greater abundances of Prevotella, ChristensenellaceaeR7, Rosburiaand Bacteroides, among others (P< 0.05). In conclusion, drinking water from either water line did not have major effects on the gut microbiome of pigs, except for more fecal bacterial diversity in pigs drinking water from the new water line at day 4 post-weaning.

The objective of this study was to determine whether feeding live yeast to sows from day 85 of gestation and through lactation influences pig performance and microbiomes in the postweaning period. Three dietary treatments were imposed on mixed-parity sows during late gestation and lactation based on the inclusion level (%) of Actisaf Sc47 in corn/soybean meal-based diets: Control (C, 0%), Low (L, 0.1%), and High (H, 0.5%). Pigs (n = 240; 80/maternal dietary treatment group) were selected randomly at weaning (~19 days old) for further performance data collection throughout the nursery period. A subset of these pigs (n = 180; 60/maternal treatment group) were selected randomly for microbiome sampling through fecal swabs collected on days 4 (T1) and 28 (T2) postweaning. Pigs were housed in pens in a confinement nursery barn according to maternal dietary treatment group (10 pigs/pen; 0.28 m2/pig of floor space; 8 pens/treatment group). Treatment groups were kept separate from each other by maintaining one empty pen between treatment groups to prevent potential microbial cross-contamination. Pigs were balanced by litter, body weight, and sex during nursery allotment. Pigs had ad libitum access to water and a common industry-relevant diet, fed in four phases from weaning through day 42. Pigs were weighed individually at the end of each dietary phase (d4, d14, d28, d42). DNA was extracted from fecal swabs and sequenced on the MiSeq platform, targeting the V4 variable region of the 16S rRNA bacterial gene. Sequence data were analyzed using QIIME2 and DADA2, plus various packages within the R statistical software. Performance data were analyzed using repeated measures and generalized linear mixed models that included maternal treatment as a fixed effect, maternal parity as a random effect, and pen as the experimental unit. Daily weight gain was greater for L pigs (0.47 kg) compared with H pigs (0.42 kg; P< 0.05), while ADFI was increased for L pigs (0.57 kg) compared with both C and H pigs (0.49 and 0.47 kg, respectively; P< 0.05; see Table). No differences in microbiome diversity were observed at either time-point. However, microbiome composition differed based on maternal treatment group at both time-points (T1: PERMANOVA, R2= 0.02, P=0.001; T2: PERMANOVA, R2= 0.04, P=0.001). These results indicate that live yeast supplementation in sow diets in late gestation and lactation may have lasting effects on pig performance and microbiome composition in the post-weaning period.

The objective of this study was to investigate effects of live yeast supplementation of sow diets during late gestation and lactation on sow reproductive performance and piglet microbiome development. Three dietary treatments were imposed on mixed-parity sows (n = 92) from three contemporary farrowing groups during late gestation and lactation. Dietary treatments were based upon the inclusion level (%) of Actisaf Sc47 in corn/soybean meal-based diets: Control (C, 0%), Low (L, 0.1%), and High (H, 0.5%). Sows were fed their assigned gestation diet (1.8 kg ∙animal-1∙day-1/) from days 85 to 110 of gestation. On day 111 of gestation, sows were fed their assigned lactation diet (3.6 kg/head/day) until parturition. Sows were allowed ad libitum access to their assigned lactation diet beginning day one postpartum until piglets were weaned. Fecal and vaginal swabs were collected from all sows on day 85 of gestation (T1-S) and the day before parturition (T2-S). Colostrum and milk samples were collected from 30 focal sows (10/treatment group), and fecal swabs were collected from 6 piglets per focal sow (n = 180) at 24 to 36 hours after birth (T1-P) and weaning (T2-P, ~19 days old). Extracted DNA from swab samples was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 plus various packages within the R statistical software. Generalized linear mixed models were built for sow performance data using the R lme4 package, with treatment as a fixed effect, and farrowing group, parity, and sire as random effects. Piglet performance models also included sex as a fixed effect and maternal origin instead of sire as a random effect. No significant differences were observed among dietary treatment groups for gestation or lactation length, lactation feed intake, sow body weights, sow backfat depth, litter size at birth or weaning, pre-weaning piglet mortalities, or piglet growth performance. Although alpha and beta diversity did not differ among maternal dietary treatment groups in sow colostrum, milk, fecal, or vaginal samples (T1-S or T2-S), several taxa were significantly enriched or less abundant in sow samples based upon dietary yeast inclusion levels. Diversity of piglet fecal microbiomes was not different across maternal dietary treatment groups, but community composition was different at both time-points (T1-P: PERMANOVA, R2= 0.13, P=0.02; T2-P: PERMANOVA, R2= 0.01, P=0.048). These results indicate that yeast supplementation in sow diets in late gestation and lactation may influence development and composition of piglet gut microbiomes in early life.

Gestating sows (n = 267) were used to determine if timing of high dietary zinc supplementation in a commercial setting would reduce pre-weaning mortality of pigs and influence maternal and piglet copper (Cu), iron (Fe), and zinc (Zn) concentrations. Sows from three consecutive weekly farrowing groups were assigned randomly within parity to one of three dietary treatments consisting of: 1) Control: a corn-soybean meal diet containing 125 ppm supplemental Zn supplied by zinc hydroxychloride; 2) Breed-to-Farrow (B-to-F): as Control + 141 ppm supplemental Zn as ZnSO4(266 ppm total supplemental Zn) fed from 5 days after breeding to farrowing; and 3) Day 110-to-Farrow (D110-to-F): as the Control diet fed from breeding to farrowing + 2,715 ppm supplemental Zn as ZnSO4(2,840 ppm total supplemental Zn) starting on day 110 of gestation until farrowing. A subset of ten sows per treatment (n = 30; average parity = 3) were selected to assess Cu, Fe, and Zn concentrations of serum, colostrum, and milk. Sera were isolated from blood collections at allotment and the day before respective farrowing date of each sow. Colostrum was collected the day of farrowing and milk on day 2 of lactation. At farrowing, two average and two low birth weight pigs from each sow (n = 122) were selected for collections of serum and tail samples at days 1 and 2 of age, respectively. The statistical model included fixed effects of treatment, farrowing group, and the random effect of their interaction. The piglet model was similar but included the random term of pig nested within sow. There were no differences in concentrations of Cu, Fe, and Zn in sow serum, milk, or colostrum attributable to dietary treatment. Piglet serum concentrations of Cu, Fe, and Zn were unaffected by feeding gestating sows high levels of supplemental zinc at any time (Table). Low birth weight pigs born to sows fed the Control diet tended (P= 0.082) to have increased concentrations of Cu in tails compared with pigs born to sows fed high zinc. In conclusion, timing of dietary zinc supplementation to gestating sows had minimal influence on concentrations of important trace elements in sows and their offspring.

Pigs (n = 3,990) were used in a previous study to determine if supplemental zinc fed to sows at various timepoints during gestation would reduce pre-weaning mortality. Additionally, data were analyzed to evaluate the effect of birth weight on tissue concentrations and distribution of copper (Cu), iron (Fe), and zinc (Zn) in piglets. Mixed parity sows were fed 1 of 3 diets: a control corn-soybean meal diet containing 125 ppm supplemental Zn supplied by zinc hydroxychloride, a diet consisting of the control + 141 ppm supplemental Zn as ZnSO4(266 ppm total supplemental Zn) fed from 5 days after breeding to farrowing, or the control diet fed from breeding to farrowing + 2,715 ppm of supplemental Zn from ZnSO4(2,840 ppm total supplemental Zn) starting on day 110 of gestation until farrowing. Two low and 2 average birth weight pigs (n = 122) were selected from 10 sows per treatment group to assess Cu, Fe, and Zn concentrations of serum and tails. Serum was collected from each pig at day 1 of age and tails were collected on day 2 of age. Liver tissue was collected from a subset of pigs (n = 65) that died naturally or were euthanized within 2 days of age. The statistical model included fixed effects of treatment and farrowing group, the random effect of their interaction, and the random effect of pig nested within sow. Serum concentrations of each trace element did not differ by birth weight (Table). Low birth weight piglets had greater concentrations of Fe (P= 0.018) and Cu (P= 0.031) in their tails than average birth weight pigs. No differences were observed in tail Zn concentration by birth weight. Notably, pigs that died naturally weighed less at birth than euthanized pigs (P< 0.001). Moreover, pigs that died naturally had greater hepatic Fe concentrations (P< 0.001) and tended to have greater liver Cu concentrations (P= 0.098) compared with euthanized pigs. The associations between tissue iron and copper concentrations and birth weight of piglets may have nutritional and pathophysiological implications and thus warrant further investigation.

An industry survey and animal experiment were conducted to evaluate the amino acid (AA) compositional variability and standardized ileal digestibility (SID) of AA in animal protein by-products fed to growing pigs. Animal protein by-product meals (212) were categorized into 8 groupings (blood meal, chicken by-product meal, chicken meal, feather meal, meat and bone meal, meat meal, poultry by-product meal, and poultry meal) and analyzed for total AA. Amino acid analysis among (e.g., Lys in blood meal averaged 9.20% compared with 2.31% for feather meal, DM basis) and within (e.g., Lys range of 1.54% in blood meal and 1.44% in feather meal, DM basis) the by-product classifications varied as expected, but on average the total AA values were similar to that reported in the literature. For the determination of the SID of AA, 15 barrows (average initial and final BW of 31.6 and 78.7 kg, respectively) were fitted with a T-cannula in the distal ileum and allotted to 15 diets over nine 7-d periods, resulting in 9 replications per diet. Pigs were fed a basal diet based on soybean meal and dehulled-degermed corn, 13 diets containing 17.5% animal protein by-product meal to partially replace a portion of the soybean meal and dehulled-degermed corn in the basal diet, or a N-free diet. Pigs were re-allotted to diets based on minimizing the number to times that the N-free diet would precede or follow feeding either of the blood or feather meal diets because of concern with inadequate diet consumption, as well as to prevent diets from being re-fed to the same pig during the next or subsequent periods. Values for the apparent ileal AA digestibility of each diet were determined, adjusted to SID based upon the endogenous AA losses determined by feeding the N-free diet, and the SID of AA in each animal protein by-product meal calculated using the difference procedure. The SID of AA varied among (e.g., SID of Lys averaged 91% in chicken meal but 47% in feather meal) and within (e.g., SID of Lys in three meat and bone meals was 80%, 71%, and 54%) the animal protein by-product meals, as would be expected and are consistent with variation reported in the literature. Overall, the data provide total AA composition for 212 samples and SID of AA for 13 samples of animal protein by-product meals, including data on their variability, which is critical for their use in feed formulation programs.

As a result of genetic selection for increased litter size, modern, highly prolific sows often produce large litters with an increased percentage of light birth weight (BiW) piglets compared with less prolific females. However, there is limited information elucidating what proportion of light BiW piglets that express compensatory growth and how these pigs might be identified at a young age. The objective of this study was to analyze the effect of birth weight and early phase growth on preweaning mortality, subsequent growth performance, and carcass characteristics of pigs. Individual records collected on 7,654 commercial crossbred pigs were used for analyses. A segmented regression model was used to analyze the effect of birth weight on preweaning survival and a series of mixed models were used to analyze the effect of birth weight (n = 7,654) group on weights recorded at: weaning (n = 6,777), nursery exit (n = 4,805), and finishing exit (n = 1,417); hot carcass weight (HCW), and lean percentage (n = 4,572). The effect of growth rate group was defined during suckling (< 225 or ≥ 225 g/d) or the nursery phase (< 424 or ≥ 424 g/d). Preweaning mortality, growth rate, BW, and carcass traits were adjusted to a standard age, and ADG and lean percentage were calculated. Results of segmented regression analysis showed that the slope of preweaning mortality on birth weights below 0.99 kg differed (P < 0.05) from the slope of preweaning mortality regressed on birth weights above 0.99 kg. The mixed model analyses showed a positive linear effect (P < 0.05) of BiW and quadratic effect (P < 0.05) of sow parity on age-adjusted finishing weight (FiW), HCW, and lean percentage. The positive influences of increasing BiW were greater (P < 0.05) in age-adjusted FiW and HCW for pigs with slow suckling growth rate compared with those with fast suckling growth rate. Pigs with fast nursery growth rate had greater (P < 0.05) age-adjusted FiW and HCW compared with the slow growing nursery contemporaries. In conclusion, piglets born weighing less than 1 kg were at a higher risk of preweaning mortality than piglets born weighing 1 kg or greater. Light BiW pigs, but not heavy BiW pigs, may lose compensatory growth capability if growth rate during the suckling phase is below the average level.