Abstract
OmniGen-AF (Phibro Animal Health, Teaneck, NJ; OG), an immuno-modulator consisting of a blend of vitamins, minerals, and microbial ingredients, has been employed in the dairy industry to mitigate the effects of heat stress and metabolic and immune system challenges on milk production. We previously reported that OG, fed to sows before and during lactation, decreased lactation BW loss, and increased litter birth and weaning weights (Lee et al., J. Anim. Sci. 99[Suppl. 3]:410-411, 2021). The objective of this study was to further these findings, by evaluating the effects of OG on feed intake and reproductive performance of crossbred sows. Berkshire x Duroc and Yorkshire x Landrace sows (n = 44; mean BW and parity, 276 kg and 4.6, respectively) from 10 farrowing groups and paired by parity and BW, were randomly assigned within pairs to one of two treatments: a fortified corn and soybean-meal based control diet (CON), or control diet top-dressed with 30 g of OG∙animal(-1)∙day(-1). Sows consumed appropriate diets for approximately 35 d before expected farrowing date, throughout lactation, and the weaning to estrus interval. Sows were fed 2.7 kg∙animal(-1)∙day(-1) during gestation, on an ad libitum basis during lactation, and 2.3 kg∙animal(-1)∙day(-1) post-weaning. Total pigs born (12.3), pigs born alive (10.5), and pigs weaned (8.9) did not differ (P > 0.32) between treatments. Average birth weights, however, for both total pigs born (1.65 vs. 0.49 kg, SE = 0.11, P < 0.04) and pigs born alive (1.73 vs. 0.55 kg, SE = 0.11, P < 0.01) were greater for OG vs. CON sows. Pig BW at weaning were similar (P = 0.51) for OG (6.58 ± 0.25) and CON (6.34 ± 0.25). The ADFI during lactation tended to be greater (P = 0.09) for OG vs. CON sows (5.81 vs. 5.08 kg, SE = 0.29); however, total BW loss did not differ (P = 0.14) between treatments (10.0 and 5.2 kg, SE = 2.4 for OG and CON, respectively). The wean to estrus interval (5.1 d) was similar (P = 0.77) between groups. Under the conditions of this study, OG enhanced pig birth weights and sow feed consumption during lactation. The mechanisms responsible for these effects warrant further scrutiny.