Effects of various feed additive strategies on broilers given 10× live coccidiosis vaccine

Abstract

Currently, there is a need to investigate feed additive application strategies, especially those used in conjunction with live coccidiosis vaccines (LCV). The objective of this study was to determine the effects of the inclusion strategies of several commercially available feed additives using broilers sprayed with 10× live coccidiosis vaccines (LCV) throughout a 49 d grow-out. All birds received 10× LCV on d of hatch, excluding treatment (Trt) 1, the unmedicated negative control (NC). The positive control (PC; Trt 2), was also unmedicated, but birds were sprayed with 10× LCV. Birds assigned Trts 3 to 8 also received LCV, and diets consisted of the following additives: Virginiamycin (VA) at 20 g/t throughout with Salinomycin (SAL) at 40 g/t from d 14 to 28 (Trt 3); VA at 20 g/t throughout d zero to 49 (Trt 4); a Bacillus subtilis probiotic (PRO) with Bacitracin Methylene Disalicyalte (BMD) at 50 g/t from d zero to 49 (Trt 5); an herb and essential oil blend (EB) from d zero to 49 (Trt 6); BMD at 50 g/t throughout with an increased dose (200 g/t) from d 14 to 28 (Trt 7); and BMD at 50 g/t throughout with SAL (40 g/t) from d 14 to 28 (Trt 8). In general, birds fed Trts 3 and 7 demonstrated increased BW and BW gain when compared to those fed Trt 2 (NC). Birds fed Trt 5 exhibited similar d 49 BW to that of birds fed Trt 3 and 7 — however, better than those fed Trt 2. Of these Trts, birds fed Trt 3 demonstrated at d 17 increased ileal digesta viscosity and reduced lesion scores caused by Eimeria acervulina, although overall scores were low. Gastrointestinal organ measurements and morphology at d 17 were not significantly affected by Trt. Overall, these data suggest that feed additive strategies utilized in Trts 3, 5, and 7 are a viable option with using LCV.