Coccidia Vaccine Challenge and Exogenous Enzyme Supplementation in Broiler Chicken 1. Effect on Digesta Viscosity, Diet Energy Utilization, and Apparent Metabolizable Energy Value of Wheat

SIMPLE SUMMARY: Eimeria species parasite can have great impacts on the health and nutrient and energy utilization of broiler chickens. This study examined the effect of Eimeria species challenge on broiler chickens’ energy utilization when fed two types of diets with or without exogenous enzyme supplementation. Seven-day post-challenge (day 21), wheat apparent metabolizable energy was lower in birds challenged with coccidia vaccine. By day 28 (14-day post-challenge), there was no difference in the apparent metabolizable energy value of wheat. The addition of exogenous enzyme resulted in an improvement in nitrogen utilization (~6%) in challenged birds fed the corn-SBM-based diets seven-day post-challenge. This study showed that broiler chickens were negatively impacted by the coccidia vaccine challenge seven-day post-challenge, but were able to compensate for the reduction in apparent metabolizable energy of wheat 14-day post-challenge. Furthermore, enzyme supplementation decreased the digesta viscosity of birds fed a wheat-corn-soybean meal-based diet 14-day post challenge. ABSTRACT: This study examined the effect of exogenous mixed-enzyme supplementation (xylanase, β-glucanase, and pectinase) to a corn-SBM (CS) and a wheat-CS-based (WCS) diet in birds challenged with coccidia vaccine (Coccivac B-52™). The WCS-based diet was produced by replacing 30% of the energy-yielding portions of the CS-based diet with wheat. On day 14, 448 (n = 7) Cobb by-product breeder male broilers were assigned to a 2 (diet types) × 2 (with or without enzyme supplementation) × 2 (0 or 20 × coccidia vaccine challenge; CVC) factorial arrangement of treatments in a completely randomized design for the determination of the apparent metabolizable energy (AME) value of wheat. Treatment effects on jejunum digesta viscosity and AME corrected for nitrogen (AMEn) of the diets were evaluated within each diet type as a 2 × 2 factorial arrangement of treatments, 7- and 14-day post-challenge. Seven-day post-challenge (day 21), dry matter (DM) and energy utilization, AME, and AMEn of the CS- and WCS-based diets decreased (p < 0.05) with CVC. Both AME and AMEn of wheat decreased (p < 0.05) by about a 20% in CVC-birds 7-day post-challenge. Enzyme and CVC resulted in a decrease (p < 0.05) in jejunal digesta viscosity in birds fed the CS-based diets, while there was an interaction (p < 0.05) between CVC and enzyme, with enzyme lowering (p < 0.05) the viscosity of digesta 7-day post-challenge. Results from this study showed that CVC resulted in a 20% decrease in AMEn 7-day post-challenge, while the interaction between exogenous enzyme supplementation and CVC resulted in an improvement in nitrogen utilization (~6%) in CVC birds fed the corn-SBM-based diet 7-days post challenge.