Effects of dietary berberine hydrochloride on growth, immunity, meat quality, and fecal microbiota in broiler chickens

This study aimed to explore the impact of dietary berberine hydrochloride (BBH) on 600 one-day-old AA+ broilers. The broilers were randomly allocated into five groups: a control group (TR) and four experimental groups supplemented with 25, 50, 100, or 200 mg/kg of BBH (designated as Ber25, Ber50, Ber100, and Ber200, respectively). The 42-day experiment consisted of six replicates per group. The results indicated that from 1 to 21 days of age, BBH had no significant influence on growth parameters such as body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR). However, during 22-42 days and 1-42 days, 50-mg/kg BBH (Ber50) significantly increased BWG and FI, showing a quadratic effect. BBH linearly enhanced the spleen and bursa indices, with the spleen index in the Ber200 group higher than that in the Ber25 group. In 42-day-old broilers, the Ber200 group had the highest levels of antibodies against Newcastle disease and avian influenza H9, presenting both linear and quadratic effects. The Ber100 treatment maximized the pectoralis CIE <i>L</i>* value, and the Ber200 treatment increased the shear force. BBH decreased fecal <i>Salmonella</i> counts, demonstrating linear and quadratic effects, and it had a linear impact on <i>Lactobacillus</i> counts, although no inter-group differences were observed. In conclusion, 50 mg/kg of BBH improved broiler growth performance, while higher doses such as 200 mg/kg enhanced immunity, reduced <i>Salmonella</i> levels, but also increased meat shear force.