Abstract An experiment was conducted to evaluate the effects of a titrated inclusion of a phytogenic polyphenol blend (AOXTM, Cargill Animal Nutrition and Health, Wayzata, MN) on nursery pig performance. In total, 1,936 weaned pigs (6.5 ± 0.09 kg initial body weight; BW) were allotted to 22 replicate pens per treatment (22 pigs per pen) in 2 barns. Pens were blocked by location within barn and randomly allotted to 4 treatments. Dietary treatments were fed in the first two nursery phases (phase 1: day 0 to 11; phase 2: day 11 to 23). All diets contained 75 IU/kg of vitamin E, with a polyphenol blend added to achieve total vitamin E equivalence of 145, 225, 375, or 675 IU/kg across treatments. All diets included in-feed antibiotics, pharmacological levels of zinc, and several other health-supporting feed technologies. All pens received antibiotics via water and individual pig injectable medications were permitted as warranted. Pen weights were recorded at the beginning and end of each phase. Data were analyzed using the lme4 package of R 4.1.2, and the statistical model included the fixed effect of treatment and the random effects of block and barn. Mortality and removals were analyzed as a generalized linear mixed model with binomial distribution and reported as probabilities. Phase 1 growth performance (BW, average daily gain ADG, average daily feed intake ADFI, and gain:feed G:F) did not differ among treatments. Phase 2 ADG did not differ among treatments; however, a quadratic reduction (P 0.05) in ADFI was observed with greater vitamin E equivalence, which resulted in a linear tendency (P 0.10) for greater G:F with increased vitamin E equivalence from the polyphenol blend. Likewise, overall ADFI (day 0 to 23) tended to quadratically decrease (P 0.10) while G:F tended to linearly increase (P 0.10) with greater polyphenol inclusion. Final BW and overall ADG were not different among treatments. Overall mortality and removals did not significantly differ among treatments, though the lowest vitamin E equivalence resulted in the numerically highest mortality and removals. In conclusion, increasing vitamin E equivalence in early nursery diets improved overall feed efficiency, and overall mortality and removals were numerically reduced when the polyphenol blend was included above 145 IU/kg vitamin E equivalence.
May et al. (Wed,) studied this question.