Effects of negative dietary cation-anion difference and calcidiol supplementation in transition diets fed to sows on piglet survival, piglet weight, and sow metabolism.

Diets that provide a negative dietary anion cation difference (DCAD) and supplement with a vitamin D metabolite 25-OH-D3 (calcidiol) may increase calcium availability at parturition, and enhance piglet survival and performance. This factorial study assessed the effects of DCAD, calcidiol (50 µg/kg), and parity (parity 1 or >1) and their interactions. Large White and Landrace sows (n = 328), parity 1 to 8 were randomly allocated in blocks to treatment diets from day 103 of gestation until day 3 postfarrow: 1) negative DCAD without calcidiol (negative DCAD + no CA), n = 84, 2) negative DCAD with calcidiol (negative DCAD + CA) n = 84, 3) positive DCAD without calcidiol (negative DCAD + no CA), n = 81, and 4) positive DCAD with calcidiol (positive DCAD + CA), n = 79. Negative DCAD diets were acidified with an anionic feed (2 kg/t) and magnesium sulfate (2 kg/t). All treatment diets contained cholecalciferol at 1,000 IU/kg. Dry sow diets contained 14.8% crude protein (CP), 5.4% crude fiber (CF), 0.8% Ca, and 83 mEq/kg DCAD. Treatment diets 1 and 2 contained 17.5% CP, 7.3% CF, 0.8% Ca, and -2 mEq/kg DCAD. Treatment diets 3 and 4 contained 17.4% CP, 7.4% CF, 0.8% Ca, and 68 mEq/kg DCAD. Before farrowing, all negative DCAD sows had lower urine pH than all sows fed a positive DCAD (5.66 ± 0.05 and 6.29 ± 0.05, respectively; P < 0.01); urinary pH was acidified for both DCAD treatments indicating metabolic acidification. The percentage of sows with stillborn piglets was not affected by DCAD, calcidiol, or parity alone but sows fed the negative DCAD + CA diet had a 28% reduction in odds of stillbirth compared to the negative DCAD + no CA diet and even lesser odds to the positive DCAD + CA diet. At day 1 after farrowing, blood gas, and mineral and metabolite concentrations were consistent with feeding a negative DCAD diet and that negative DCAD diets influence energy metabolism, as indicated by increased glucose, cholesterol, and osteocalcin concentrations and reduced nonesterified free fatty acids and 3-hydroxybutyrate concentrations. In the subsequent litter, total piglets born and born alive (14.7 ± 0.3 and 13.8 ± 0.3 piglets, respectively; P = 0.029) was greater for positive DCAD diets compared to negative DCAD diets; and there was an interaction between DCAD, calcidiol, and parity (P = 0.002). Feeding a negative DCAD diet influenced stillbirth, subsequent litter size, and metabolic responses at farrowing. More studies are needed to define optimal diets prefarrowing for sows.

The transition period between late gestation and lactation is critical to farrowing and successful lactation; sows with higher blood calcium have less risk of dystocia. We evaluated transition diets that provided a negative dietary cation­anion difference (DCAD) and supplemented with calcidiol (CA), both of which influence calcium metabolism. Purebred Landrace or Large White sows (n = 328) were enrolled in the experiment and selected sows that were either primiparous (n = 99) or multiparous (n = 229; average parity = 2.59 ± 1.51; parity range = 1 to 8) were fed a dry sow ration until day 103 of gestation and were then fed transition diets until day 3 postfarrowing in a factorial study. The diets were formulated to include 1) negative DCAD + no CA, 2) negative DCAD + CA, 3) positive DCAD + no CA, or 4) positive DCAD + CA. All diets induced a metabolic acidosis as indicated by urinary pH. Sows fed the negative DCAD with added calcidiol had a >28% reduction in odds of stillbirth over negative DCAD + no CA and positive DCAD + CA diets. Following weaning and re-mating, there were 0.9 more piglets born in the subsequent litter for both positive DCAD diets compared to negative DCAD diets. Blood gas, and mineral and metabolite concentrations provided evidence that negative DCAD diets positively influenced energy metabolism.

Effects of postweaning supplementation of immunomodulatory feed ingredient on circulating cytokines and microbial populations in programmed fed beef heifers.

The objective was to determine the effects of an immunomodulatory feed ingredient following weaning on cytokine expression and fecal microbial populations of heifers. Commercial Angus heifers (n = 72) were weaned (227 ± 7 d of age), blocked by BW (n = 9 blocks), and randomly assigned to one of two pens per block. Pens within weight block (four heifers per pen) were then randomly assigned to treatments. Heifers were fed twice daily from days 0 to 60 (to gain 0.75 kg/d) and top dressed with either 18 g/heifer/d of the immunomodulatory feed ingredient (Celmanax; Arm and Hammer Animal Nutrition, Princeton, NJ; CEL) or corn-germ meal (CON). Blood samples were collected on days 0, 15, 30, 45, 60 and fecal grab samples on day 0 of the feeding trial. After day 60, two heifers per pen (n = 32) were randomly selected for a transportation challenge. Serum samples were collected at hours 0, 4, 8, 12 and fecal grab samples at hours -24, 0, 24 and 7 d postchallenge. Blood samples were analyzed for interferonγ (IFNγ), interleukin-8 (IL-8), and haptoglobin (HP) using commercially available ELISA kits and qRT-PCR for genes of interest associated with cytokine expression. Fecal samples were enumerated for Clostridia and E. coli using selective media (≤5 isolates from each media/sample), tested to determine whether they were Clostridium perfringens or pathogenic E. coli, and then enriched for detection of Salmonella. Data were analyzed via ANOVA. During the feeding trial, HP was reduced (P = 0.018) in CEL compared with CON at days 15, 45, and 60, whereas IFNγ and IL-8 did not differ (P > 0.080) between treatments. All cytokines were decreased (P < 0.001) in CEL compared with CON during the challenge. During the feeding trial, HP mRNA was increased (P = 0.045) in CEL compared with CON at days 30 and 60. Similarly, IFNγ mRNA was increased (P = 0.040) in CEL compared with CON; however, other genes of interest did not differ (P > 0.172). Both C. perfringens and total E. coli counts were decreased (P = 0.036) in CEL compared with CON at 24 h after the start of the transportation challenge. Clostridia and pathogenic E. coli counts did not differ (P = 0.941) between treatments. Total Clostridia and E. coli counts were increased (P < 0.014) 24 h postchallenge. All microbial populations, except pathogenic E. coli, observed decreased (P ≤ 0.009) counts from 24 h to 7 d postchallenge. Overall, Celmanax supplementation decreased circulating cytokines, and altered microbial populations and gene expression, thus, may serve a role in preparing animals to better cope with immunological challenges.

With consumers wanting less antibiotic usage in cattle production, the need for natural feed ingredients that have positive effects on animal health are needed. The feeding of a yeast-based feed product decreased cytokines in the blood and their mRNA expression in white blood cells that act on stimulating an inflammatory response. When an animal has an inflammatory response, their immune system is working harder than necessary. This means they are using energy that could otherwise be used for growth, which decreases efficiency and performance. The feeding of this yeast-based feed ingredient also reduced the amount of harmful bacteria in the feces of the heifers. Having lower amounts of harmful bacteria (such as Salmonella) in the feces decreases the chance of carcass contamination. For consumers, this means less instances of food-borne illnesses.

Neutrophil ß-defensin gene expression of postpartum dairy cows is altered by prepartum dietary cation-anion difference.

The objective of this study was to evaluate expression of a cluster of genes encoding ß-defensin antimicrobial peptides in neutrophils of postpartum cows in relation to prepartum dietary cation-anion difference (DCAD), vitamin D, and postpartum disease. Pregnant dry Holstein cows (28 nulliparous and 51 parous) at 255 d gestation were blocked by parity and randomly assigned to 4 prepartum diets of positive (+130 mEq/kg) or negative (-130 mEq/kg) DCAD and either 3 mg vitamin D3 or 3 mg of 25-hydroxyvitamin D3 per 11 kg of dry matter/d. Treatment diets were fed from 255 d of gestation until calving. Peripheral blood neutrophils of 35 parous cows were collected at 0 and 3 d after calving and stimulated with 0 or 100 ng/mL of lipopolysaccharide (LPS). Furthermore, serum Ca and incidences of postpartum diseases were recorded for all cows. The mRNA transcripts of ß-defensin genes were quantified by real-time PCR, and data were analyzed with a general linear mixed model to test for fixed effects and interactions of day, level of DCAD, source of vitamin D, and incidence of disease. Effects of DCAD and vitamin D on neutrophil oxidative burst and phagocytosis were previously reported but were analyzed for effects of disease in the present study. Transcripts for DEFB1, DEFB3, DEFB4, DEFB5, DEFB7, DEFB10, and lingual antimicrobial peptide (LAP) in neutrophils were upregulated by LPS at 0 d but not at 3 d. Transcripts for DEFB4 and DEFB7 in LPS-stimulated neutrophils were greater in cows fed negative DCAD diets compared with positive DCAD. Source of vitamin D (vitamin D3 vs. 25-hydroxyvitamin D3) did not affect expression of ß-defensins in neutrophils. Cows with postpartum subclinical hypocalcemia (serum Ca <2.0 mM) had decreased DEFB3, DEFB4, DEFB6, DEFB7, DEFB10, and LAP expression in LPS-stimulated neutrophils compared with cows that did not experience subclinical hypocalcemia. Likewise, DEFB4, DEFB6, DEFB7, DEFB10, and LAP in LPS-stimulated neutrophils at 3 d postpartum were positively associated with serum Ca at 0 d postpartum. Transcripts for DEFB7, DEFB10 and LAP also were less abundant in neutrophils from cows with metritis compared with healthy cows. In conclusion, feeding a prepartum negative DCAD to improve postpartum serum Ca resulted in greater neutrophil ß-defensin expression, and greater neutrophil ß-defensin expression was positively associated with postpartum health.

Effect of stearic or oleic acid on milk performance and energy partitioning when fed in diets with low and high rumen-active unsaturated fatty acids in early lactation.

This experiment was conducted to determine the effects of stearic acid (SA; C18:0) or rumen-protected oleic acid (OA; C18:1 cis-9) on milk performance and energy partitioning of early lactation cows when supplemented in diets with low and high level of rumen unsaturated fatty acids (RUFA). In low RUFA experiment (LRUFA), FA supplement rich in either SA or calcium salts OA was added to a basal diet with a low concentration of RUFA (0.75% vs. 1.4%, LRUFA-SA vs. LRUFA-OA). In high RUFA experiment (HRUFA), 2% soybean oil was added to the diet fed in the LRUFA experiment. In each experiment, 30 multiparous cows were blocked by parity and predicted transmitting ability for milk yield and were randomly fed 1 of 2 treatment diets from 2 to 13 wk postpartum. In the LRUFA experiment, LRUFA-SA had 2.4 kg/d more dry matter intake (DMI) (P < 0.01), 3.8 kg/d more energy-corrected milk (P < 0.01), and 0.3% units more milk fat percentage (P < 0.01) and 0.2 kg/d more milk fat yield (P < 0.01). Dietary treatments did not affect body weight, energy balance, and energy intake partitioning into milk, maintenance, and body tissues (P > 0.1). In the HRUFA experiment, HRUFA-SA had 1.4 kg/d more DMI (P = 0.03) but similar milk and milk components yields (P > 0.1). HRUFA-SA had a tendency to gain more body weight (P = 0.07) and had more positive energy balance (P = 0.01) and decreased gross feed efficiency (milk yield/DMI) (P = 0.01). Consistently, HRUFA-SA increased intake energy partitioning into body tissues (P = 0.02) and decreased energy partitioning into milk (P = 0.01). In summary, SA supplementation had more DMI relative to OA, but the effects on milk and milk fat production were different and affected by the level of RUFA in the basal diet. In application, SA supplementation was more effective to improve milk production when included in the basal diet with the low RUFA.