Justin W Bundy

Effect of dam parity on litter performance, transfer of passive immunity, and progeny microbial ecology

Litter performance and progeny health status may be decreased in progeny derived from primiparous sows but improve with increasing parity. The objective was to evaluate litter performance, the production and passive transfer of Ig, and fecal microbial populations in progeny derived from first parity (P1) compared with fourth parity (P4) dams. Litter performance was recorded for P1 (n = 19) and P4 (n = 24) dams including number of pigs/litter (total born, born live, stillbirths, mummified fetuses, prewean mortality, and pigs weaned) and average litter and piglet BW at birth (d 0), d 7, d 14, and at weaning (average d 19). Blood samples were collected from all dams on d 90 and 114 of gestation and d 0 of lactation. Colostrum and milk samples were collected from each dam on d 0, 7, and 14 of lactation for quantification of IgG and IgA. Blood and fecal samples were collected from each litter (n = 6 pigs/litter) on d 1, 7, and 14 after parturition. Circulating IgG and IgA concentrations were quantified in all blood samples. Denaturing gradient gel electrophoresis (DGGE) was used to characterize similarity and diversity of fecal microbes among progeny. Progeny of P1 dams had decreased average litter BW at d 7 (25.7 vs. 30.0 kg; P < 0.03) and decreased average piglet BW throughout the experiment (d 0, 7, 14, and 19; P < 0.001) compared with P4 progeny. No parity × day interactions were observed with respect to immunoglobulin or microbial analyses. Concentrations of IgA tended to be greater (P = 0.09) in samples of colostrum and milk obtained from P4 compared with P1 dams. Serum IgG concentrations were greater (P < 0.02) in P4 progeny compared with P1 progeny. Results of DGGE revealed that P1 progeny had increased (P < 0.001) microbial similarity on d 7 and decreased (P < 0.03) microbial similarity on d 14 compared with P4 progeny. Progeny of P1 dams tended (P = 0.07) to have a greater Shannons diversity index compared with P4 progeny on d 1, and P1 progeny had a greater (P < 0.03) Shannons diversity index compared with P4 progeny on d 7. Litter performance, passive transfer of immunity, and progeny microbial ecology were affected by dam parity.

Effects of spray-dried porcine plasma on growth performance, immune response, total antioxidant capacity, and gut morphology of nursery pigs

Two experiments were conducted to evaluate the effects of spray-dried porcine plasma (SDPP) on growth performance, immunity, antioxidant capacity, and gut morphology of nursery pigs. In Exp. 1, 96 weaned pigs (Nebraska female × Danbred sire; 20 ± 1 d of age; initial BW = 6.06 ± 0.02 kg) were assigned to 16 pens and randomly allotted to the control (CTL; no SDPP) or the CTL + SDPP treatment in 2 phases (phase 1: d 0 to 14, 5% SDPP; phase 2: d 14 to 28, 2.5% SDPP). Blood samples were collected on d 0 and weekly thereafter to quantify IgG, IgA, and total antioxidant capacity. On d 14, pigs (n = 16; 8 pigs/treatment) were selected and euthanized for small intestine tissue and alveolar macrophage collection. On d 7, pigs fed SDPP had greater ADG, ADFI (P = 0.001), and G:F (P = 0.019) compared with CTL pigs. On d 28, pigs fed SDPP had greater BW (P = 0.024) and tended to have greater ADG (P = 0.074) and ADFI (P = 0.062) compared with CTL pigs. There were no differences between treatments for serum IgG, IgA, and total antioxidant capacity. On d 14, greater villus height (P = 0.011) and villus:crypt (P = 0.008) were observed in duodenal tissue sections obtained from SDPP-fed pigs compared with CTL pigs. To evaluate effects of SDPP on immune biomarkers, alveolar macrophages collected from 3 pigs/treatment on d 14 were cultured in vitro and challenged with lipopolysaccharide (LPS; 10 ng/mL). Therefore, 4 treatments included 1) CTL diet with no LPS, 2) CTL diet with LPS (CTL+), 3) SDPP diet with no LPS, and 4) SDPP diet with LPS. There were no diet effects on tumor necrosis factor-α gene expression or secretion by alveolar macrophages. For IL-10 gene expression, a diet × LPS interaction (P = 0.009) was observed where CTL+ had greater (P < 0.05) IL-10 mRNA abundance compared with other treatments. A second experiment was conducted to evaluate the in vitro effects of porcine plasma using model porcine jejunal epithelial cells (IPEC-J2). The treatments applied to the IPEC-J2 cells were 1) CTL, 2) CTL + 10% porcine plasma, 3) CTL + 5% porcine plasma, 4) CTL + 2.5% porcine plasma, or 5) CTL + 5% fetal bovine serum. The addition of porcine plasma increased (P < 0.001) proliferation of IPEC-J2 cells at 24 and 48 h following exposure to the respective treatments. In conclusion, dietary SDPP increased growth performance of nursery pigs during the first week postweaning and provide benefits to gut morphology possibly via increased proliferation of enterocytes.

Effect of corn distillers dried grains with solubles on growth performance and health status indicators in weanling pigs.

Two experiments were conducted to evaluate effects of corn distillers dried grains with solubles (DDGS) on growth performance and health status of weanling pigs. Experiment 1 evaluated effects of increasing concentrations of DDGS on growth performance and health of weanling pigs. Dietary treatments included 1) control (CTL), 2) 0% DDGS (0% DDGS in phase 2 and 30% DDGS in phase 3), 3) 5% DDGS (5% DDGS in phase 2 and 30% DDGS in phase 3), and 4) 30% DDGS (phases 2 and 3). Overall, pigs fed 30% DDGS during phases 2 and 3 had decreased (22.1 vs. 25.1 and 24.0 kg; P = 0.003) BW compared with CTL pigs and pigs that only received DDGS during phase 3. In addition, pigs fed 5 or 30% DDGS in phase 2 had decreased (422.7 or 390.0 vs. 468.2 g; P = 0.003) ADG compared with CTL pigs. However, pigs fed 0% DDGS during phase 2 had similar BW, ADG, and ADFI compared with CTL pigs. Experiment 2 was conducted to evaluate effects of DDGS, lactose, and their interaction on growth performance and health of weanling pigs. Dietary treatments included 1) CTL, 2) lactose (20%), 3) DDGS (15%), and 4) lactose + DDGS. Diets of interest were fed during phase 1 (d 0 to 14), and a common diet was fed during phase 2 (d 14 to 28). Pigs receiving DDGS in phase 1 had greater ADG (576.2 vs. 534.6 g; P = 0.01) and ADFI (814.9 vs. 751.6 g; P = 0.01) during phase 2 compared with non-DDGS-fed pigs. Pigs receiving lactose during phase 1 had greater ADG (214.7 vs. 177.2 g; P = 0.01) and G:F (741.0 vs. 660.3 g/kg; P = 0.01) and tended to have greater ADFI (289.3 vs. 267.6 g; P = 0.07) during phase 1 but decreased (537.7 vs. 573.1 g; P = 0.09) ADG during phase 2. Serum immunoglobulin analyses and fecal microbial profiling were conducted in both experiments as indicators of health status. No effects of dietary treatment were observed for serum immunoglobulin in either experiment. Fecal microbial profiling resulted in statistically significant effects of dietary treatment with respect to microbial similarity and diversity indices (Exp. 1) and lactic acid-producing bacteria (Exp. 2), where main effects of both lactose and DDGS were observed with respect to putative Lactobacillus reuteri (P < 0.05). Results from Exp. 1 indicate that decreased concentrations of DDGS early in the nursery phase may negatively affect growth performance; however, growth performance may be maintained when inclusion of high concentrations (30%) of DDGS is delayed until the late nursery period. Results from Exp. 2 indicate that lactose may be incorporated in nursery diets containing DDGS to help maintain growth performance, and DDGS and lactose may affect fecal microbial profiles.

Effects of lactose and yeast-dried milk on growth performance, fecal microbiota, and immune parameters of nursery pigs

An experiment was conducted to evaluate the effects of dietary lactose alone or in combination with a yeast-dried milk product (50% dried near-dated milk and 50% dried yeast) on growth performance, fecal microbiota, and immune status in nursery pigs (Sus scrofa). A total of 108 pigs (age, 20 ± 1 d; initial BW, 6.07 ± 0.03 kg) were randomly allotted to 18 pens (6 pigs/pen; 6 pens/treatment). Dietary treatments were: 1) control, 2) control + lactose, and 3) control + lactose + 5% yeast-dried milk. Except for the control diet, diets in Phase 1 (wk 1 and 2), 2 (wk 3 and 4), and 3 (wk 5) contained 20, 15, and 5% total lactose, respectively. Blood samples were collected from all pigs at d 0, 14, 28, and 35 to determine circulating IgG, IgA, and tumor necrosis factor (TNF)-α concentrations. At d 0, 7, and 14, fecal samples were collected (n = 18; 6 pigs/treatment) to evaluate fecal microbiota using PCR-denaturing gradient gel electrophoresis. Compared with pigs fed the control diet, pigs fed lactose and lactose with yeast-dried milk had greater (P < 0.05) ADG and tended (P = 0.07) to have greater BW and ADFI during Phase 1. There were no differences for BW, ADG, or ADFI during Phase 2, 3, or the overall experimental period. A main effect of treatment was observed for circulating IgA where control pigs had greater (P < 0.01) IgA compared with pigs fed lactose with or without yeast-dried milk; however, no effects of treatment were observed (P > 0.10) for circulating IgG or TNF-α. No differences (P > 0.10) in microbial diversity indices were observed on d 7 or 14 among treatments. However, a shift in microbial composition was observed on d 7, with lactose-fed pigs having greater (P < 0.05) putative L. johnsonii staining intensity compared with control pigs and pigs fed lactose plus yeast-dried milk. On d 14, L. delbrueckii was eliminated (P < 0.04) by feeding lactose with or without yeast-dried milk. This research indicates that growth performance, immune status, and fecal microbiota are affected by dietary inclusion of lactose alone, or in combination with yeast-dried milk.

Genomic analysis of the differential response to experimental infection with porcine circovirus 2b

Porcine circovirus type 2 (PCV2) is the etiological agent of a group of associated diseases (PCVAD) that affect production efficiency and can lead to mortality. Using different crossbred lines of pigs, we analyzed host genetic variation of viral load, immune response and weight change following experimental infection with a PCV2b strain (n = 386). Pigs expressed variation in the magnitude and initiation of viremia and immune response recorded weekly until 28 days post-infection. A higher viral load was correlated with weight gain (r = -0.26, P < 0.0001) and presence of PCV2-specific antibodies (IgM, r = 0.26-0.34, P < 0.0001; IgG, r = 0.17-0.20, P < 0.01). In genome-wide association analyses of the responses at different time points, the proportions of phenotypic variation explained by combined effects of 56 433 SNPs were 34.8-59.4% for viremia, 10.1-59.5% for antibody response and 5.6-14.9% for weight change. Relationships between genomic prediction of overall viral load and weight gain during the first weeks of challenge were negative (-0.21 and -0.24 respectively, P < 0.0001). Individuals that carried more favorable alleles across three SNPs on SSC9 (0.60 Mb) and SSC12 (6.8 and 18.2 Mb) partially explained this relationship, having lower viral load (P < 0.0001); lower viremia at day 14 (P < 0.0001), day 21 (P < 0.01) and day 28 (P < 0.05) and greater overall average daily gain during infection (ADGi ; P < 0.01), ADGi at week 3 (P < 0.001) and week 4 (P < 0.01). These additive genetic relationships could lead to molecular solutions to improve animal health and reduce production costs.

Effects of a yeast-dried milk product in creep and phase-1 nursery diets on growth performance, circulating immunoglobulin A, and fecal microbiota of nursing and nursery pigs1

Four experiments were conducted to evaluate effects of yeast-dried milk (YDM) product in creep and phase-1 nursery diets. In Exp. 1, 24 parity-4 litters were allotted to 3 dietary treatments (8 litters/treatment) including no creep (NC), control creep (CTL), and experimental creep (EC; 10% YDM). Creep diets were fed twice daily from d 7 after birth until weaning (23.6 ± 1.8 d). In Exp. 2, 108 weaned pigs were selected based on mean BW of pigs from the respective treatments in Exp. 1. For phase 1 (d 0 to 7 postweaning) of Exp. 2, NC and CTL pigs were fed the CTL diet and EC pigs continued to receive the EC diet. For phase 2 and 3 (d 7 to 28 postweaning) of Exp. 2, all pigs received a common diet containing antibiotics. Blood and fecal samples were collected on d 0, 7, 14, and 21 postweaning to evaluate serum IgA and fecal microbiota. In Exp. 1, pigs fed EC and CTL tended to have greater (P < 0.10) weaning BW compared with NC pigs. Pigs fed EC had greater (P < 0.05) ADFI compared with CTL pigs. In Exp. 2, pigs fed EC tended to have greater BW (P < 0.10) and greater ADG (P < 0.05) and ADFI (P < 0.01) compared with CTL and NC pigs (d 0 to 28). For serum IgA, EC and CTL pigs tended (P < 0.10) to have greater IgA compared with NC pigs. For microbial data, EC pigs had greater (P < 0.01) microbial diversity compared with CTL (d 7 postweaning). On d 7 and 21 postweaning, microbial similarity decreased (P < 0.01) in pigs fed EC compared with NC and CTL. Overall (d 0 to 14), lactobacilli gene copy numbers tended (P < 0.10) to be greater in EC (7.3 log10) compared with NC pigs (6.9 log10). In Exp. 3, 23 parity-1 litters were allotted to 3 dietary treatments as described for Exp. 1. In Exp. 4, 108 weaned pigs were selected based on mean BW of all pigs from Exp. 3 and dietary treatments were the same as described for Exp. 2 except no antibiotic was included in phase-2 diet. In Exp. 3, there were no treatment effects on litter ADFI, ADG, and serum IgA, but a tendency (P < 0.10) for lower Lactobacillus reuteri in the CTL (5.1 log10) compared with NC pigs (5.6 log10) was observed. Overall (d 0 to 21) in Exp. 4, pigs fed EC had greater ADG (P < 0.01) and G:F (P < 0.05) and tended to exhibit greater ADFI (P < 0.10) compared with the CTL. For microbial data, pigs fed CTL (4.8 log10) and EC (4.8 log10) had lower (P < 0.01) fecal Lactobacillus johnsonii compared with NC (5.2 log10). Microbial ecology and immune parameters are affected by YDM.

Effects of spray-dried porcine plasma on fecal microbiota in nursery pigs

Spray-dried porcine plasma (SDPP) has been considered as an alternative for in-feed antibiotics to improve pig growth performance; however, the effect of SDPP on gut microbiota is unknown. The objective of this study was to evaluate effects of feeding SDPP on fecal microbial communities of nursery pigs. Ninety-six weaned pigs were assigned to 16 pens, which were allotted to two dietary treatments, including the control or the control + SDPP (5% and 2.5% SDPP inclusion in phase 1 and 2, respectively) diet. Fecal samples were collected at d 0, 7, 14, 21, and 28. Multiplex sequencing of V3 region of the 16S rRNA gene was used to characterize the bacterial community structure of fecal samples. Pearsons correlation tests were performed in Calypso to identify bacterial taxa that were either positively or negatively associated with overall growth performance. Feeding SDPP altered microbial structure at family, genus, and operational taxonomic unit (OTU) classifications; however, fecal microbes shifted with time. At the family level, Clostridiaceae increased (P < 0.001) on d 14, but decreased (P < 0.05) on d 28 in SDPP-fed pigs compared with control pigs. Decreased Veillonellaceae (P < 0.05; d 14) and Lachnospiraceae (P = 0.001; overall) were observed in SDPP-fed pigs compared with control pigs. Feeding SDPP increased lactic acid-producing bacteria (Lactobacillus delbrueckii, d 7) and cellulolytic bacteria (Ruminococcus albus, d 7; Clostridium thermocellum, d 7 and 14; and Clostridium saccharoperbutylacetonicum/beijerinckii, d 14; and Megasphaera elsdenii, d 21). On d 28, feeding SDPP decreased (P < 0.05) Clostridium difficile compared with control pigs. In conclusion, feeding SDPP altered fecal microbial communities in nursery pigs. The results of this study may provide information to help explain the positive effects associated with feeding SDPP on nutrient digestibility and gut health of nursery pigs.