The objective of this study was to investigate the effects of replacing antibiotics with Kudzu-leaf flavonoids (KLF) on the growth performances, gut epithelial development, and gastrointestinal bacteria diversities of Yellow-feathered broilers. For this purpose, total of 216 1-day-old male Yellow-feathered chickens with the similar birth weight (31.0  ±  1.0 g) were randomly divided into 3 treatments: the control treatment (CON), the kudzu-leaf flavonoids supplement treatment (KLF), and the antibiotics supplement treatment (AGP). All birds were provided with a 56 d-feeding procedure, followed by the measurement of production performances, immune organs, blood anti-oxidant parameters, intestine epithelium development, and cecal microbiota. Results showed the feed conversion ratio significantly decreased after KLF supplement compared with CON (P  <  0.05). KLF supplement partly promoted the anti-oxidant capacity on account of the increased activity of Superoxide dismutase (SOD) and the decrease content of malondialdehyde (MDA). Further, as referred to the gastrointestinal development and bacteria, ratio of villus/crypt significantly increased of ileum in KLF treatment (P  <  0.05) while a significant promition of bacterial diversity and partial representative probiotic bacteria (P  <  0.05) after KLF supplementation. Moreover, correlation analysis indicated that probitics including Bifidobacterium, Butyricimonas, Lactobacillus and Streptococcus positively correlated with production performances. In conclusion, KLF supplement may promote feed efficiency and benefit the gastrointestinal health through improving gut bacterial diversity and probiotic bacteria. The KLF might be applied as a proper antibiotic alternative.

The objective of this study was to investigate the effects of replacing antibiotics with Kudzu-leaf flavonoids (KLF) on the growth performances, immune capacity, and gastrointestinal health of Yellow-feathered broilers. For this purpose, total of 216 one-day-old male Yellow-feathered chickens with the similar birth weight (31.0±1.0g) were randomly divided into 3 treatments: the control treatment (CON), the kudzu-leaf flavonoids supplement treatment (KLF), and the antibiotics supplementation treatment (AGP). All birds were provided with a 56d-feeding procedure, followed by the measurement of production performances, immune organs, blood anti-oxidant parameters and cecal microbiota. Results showed the feed conversion ratio significantly decreased after KLF supplement compared with CON (P< 0.05), while no significant differences for immune organ indexes among the three treatments (P > 0.05). Further, anti-oxidant activities were partly promoted after KLF supplement on account of the increased activity of Superoxide dismutase (SOD) and the decrease content of malondialdehyde (MDA). Cecal microbiota results showed a significant promition of bacterial diversity and partial representative probiotic bacteria (P<0.05) after KLF supplementation. Moreover, correlation analysis indicated that probitics including Bifidobacterium, Butyricimonas, Lactobacillus, and Streptococcus positively correlated with production performances while negatively correlated with immune organs. In conclusion, KLF supplement may promote feed efficiency and benefit the gastrointestinal health through improving gut bacterial diversity and probiotic bacteria. The KLF might be applied as a proper antibiotic alternative.