171 Effects of a Dietary Immuno-Modulator on Growth Performance in Nursery Pigs

Abstract

Abstract Feed-grade antibiotics in pig production were used to not only treat and prevent disease, but to promote growth as well, with improvements in ADG of up to 16% and F:G of up to 6% in nursery pigs common. However, these uses may contribute to antibiotic-resistant microbes that negatively affect human and animal health, and the swine industry seeks alternatives. OmniGen-AF (Phibro Animal Health, Teaneck, NJ; OG), a blend of vitamins, minerals, and microbial ingredients is a dietary immuno-modulator used to support immune function and reduce the negative effects of stressors in dairy cattle. Weaning is inherently stressful to pigs. There are limited data, however, on the effects of OG on growth and well-being in swine. The objective was to determine the effect of dietary supplementation with OG on growth performance in 21-day-old weaned pigs. Barrows (n = 36) and gilts (n = 36) were blocked by weight, and placed in sex-specific pens of three pigs each. Within blocks, pens were assigned to ad libitum access to OG (4 g/45.4 kg∙BW-1ּּּ ∙day-1) or control diets in a 2 x 2 factorial arrangement. The factors consisted of sex and presence or absence of OG in the diets of a three-phase feeding regimen. There were 6 replicate pens per sex and dietary treatment combination. Compared with gilts, barrows were heavier (effect of sex, P < 0.01), and across diets pigs showed an increase in BW during the 42-d trial (effect of day, P < 0.01). There were no effects (P > 0.10) of diet, or diet by sex on growth performance (ADG, 0.86 vs. 0.84 kg, SE = 0.05; ADFI, 1.42 vs. 1.41 kg, SE = 0.07; and, F:G, 1.66 vs. 1.69, SE = 0.03, for OG and CON, respectively). Fecal consistency scores (1 to 5; 1 = exceptionally firm, 5 = very loose and watery) were affected by day (P < 0.01), increasing (P = 0.02) from day 0 (3.00 ± 0.07) to a peak on day 4 (3.29 ± 0.07), before decreasing to values on d 35 (3.00 ± 0.07) and 42 (3.00 ± 0.07) that were not different from values on day 0. There were no effects (P > 0.32) of diet or sex on scores. No pig deaths occurred during the experiment. In this study, dietary supplementation with OG did not affect growth performance in pigs. The experiment, however, was conducted in a clean, highly managed University facility, and overall pig health appeared excellent as indicated by daily observations, fecal consistency scores, and no mortality occurring during the study. In this situation, it would be difficult to show a positive effect of a feed additive because the pigs were perhaps already performing at or near their genetic potential.