Response of growth performance and cecum microbial communityto cyclic heat stress in broilers

Abstract

This study was conducted to examine the changes in growth performance and caecal microbiotal community in cycle heat stress (CHS) treated broilers. A total of 200 twenty-eight-day-old female Arbor Acres (AA) broilers were equally allotted into neutral ambient temperature group (TN group, 24 ± 1℃, 24 h/day) and CHS group (33 ± 1℃, 8 h/day) with five replicates of 10 broilers each, respectively. Growth performance, cecum microbial diversity, flora composition and community structure were analyzed on days 35 and 42. The decreased average daily feed intake (ADFI), average daily gain (ADG) and the increased feed/gain ratio (F:G) were observed in heat-stressed broilers on days 35 and 42. The alpha and beta diversity index had no significant changes at the two experimental periods (P > 0.05). At the genus level, CHS significantly increased the relative abundance of Enterococcus at 42 d (P < 0.05). Based on the analysis of linear effect size feature selection, CHS made an enriched Reyranella and a reduced Rompoutsia and Ruminiclostridium at 35 d of age (P < 0.05). CHS made an enriched Weissella and Enterococcus at 42 d of age (P < 0.05). The present study revealed that CHS reduces broiler growth performance and alters the microbial community of the cecum microbiota and the abundance of species. These findings are of critical importance to alleviate the negative effects of CHS on broiler chickens’ growth performance by maintaining gut microbial balance.