Age-dependent development trends (models) of intestinal significant microbiota species and Eimeria oocysts in coccidia-challenged broiler chickens as affected by dietary encapsulated organic acids and anticoccidial drugs

Abstract

ABSTRACT The study was conducted to investigate the effect of dietary encapsulated organic acids (EOAs) and anticoccidials on the age-dependent development trend of intestinal Lactobacillus, E. coli, coliforms, and Eimeria in Eimeria spp.-infected broiler chickens from reused litter. In total, 525 mixed-sex 1-day-old broiler chickens were used in an uninfected/un-supplemented control plus a 2 (no EOA or 0.1% EOA) × 3 (no anticoccidial, 0.05% maduramicin, and 0.02% diclazuril) factorial arrangement of treatments as a completely randomized design with five replicates of 15 chickens. Results indicated that the cubic model is the best model for explaining the development trends of the intestinal microbial population in uninfected and infected chickens (affected by the EOAs and anticoccidials). Based on the cubic models, the microbial populations had development trends with a decreasing slope from 1-day-old until the early or middle finisher period. EOAs and anticoccidials, especially their simultaneous usage, improved (P < 0.05) the linear and cubic models’ slope (affected negatively by Eimeria infection). A polynomial model (order = 6) was determined as the best model for explaining the EOAs and anticoccidial effects on the trend of intestinal Eimeria oocysts in infected chickens. The infection peak (which happened at 25 days) was reduced by EOAs and anticoccidials, especially their simultaneous usage. In conclusion, cubic and polynomial (order = 6) regressions are the best models fitted for explaining the microbiota and Eimeria oocysts trends, respectively. EOAs and anticoccidials, especially their simultaneous usage, had beneficial effects on the microbiota and Eimeria development trends and gastrointestinal health in coccidia-infected broiler chickens.‏ RESEARCH HIGHLIGHTS Cubic regression is the best model for explaining intestinal microbiota development. Polynomial regression is the best model for intestinal Eimeria oocysts development. Age-development trends are affected by dietary encapsulated organic acids and anticoccidials.