Comparison of the effects of compound probiotics and antibiotics on yellow-feather broilers based on growth performance, small intestine morphology and digestive enzymes activity, gut microbiota and fecal emissions

Abstract This study was devoted to the comparison of the probiotic effect of compound probiotics to the antibiotics as a chicken feed additive. Two hundred and seventy newly-hatched yellow-feather broilers were randomly divided into 3 groups, control group (Con), probiotics (Pb) and antibiotics group (Ab). Pb group received compound probiotics via drinking water for 24 days. Ab group received antibiotics in diet for 24 days. All broilers were slaughtered at day 42. Compared with Con group, the body weight significantly increased on day 13, 28 and 42 in the Pb group ( P < 0.05). Compared with Ab group, the body weight of broilers in the Pb group increased significantly on day 13 (P < 0.05), and the depth of duodenum, jejunum and ileum crypts decreased significantly relative to Con group (P < 0.05). The ratio of villi length to crypt depth in duodenum, jejunum and ileum epithelium significantly increased in Pb group compared to Con group (P < 0.05). The genera Bacteroidesand Barnesiella were the most significantly enriched bacteria in Ab and Pb groups, respectively (P < 0.05). The expression of genes related to antibiotic resistance significantly decreased in Pb group relative to Ab group (P < 0.05). Dietary compound probiotics improved growth performance, small intestinal morphology, cecal microbiome, and fecal emissions, indicating its bright future as an alternative to antibiotics in yellow-feather broiler industry.