Effect of casein bioactive peptides on performance, nutrient digestibility, enzyme activity and intestinal microbial population in broiler chickens

This experiment was carried out to investigate the effect of bioactive peptides derived from casein on performance, nutrient digestibility, enzyme activity and intestinal microbial population in broiler chickens. In this study, 350 1-day-old male Ross 308 broiler chicks were distributed among 35 pens in a completely randomized design with seven treatments, five replicates and 10 chicks in each replicate. The experimental treatments included: basal diet without any additives (control), basal diet + Avilamycin antibiotic, basal diet + 200, 400, 600, 800 and 1000 mg of peptides per kg of diet. Results showed no significant effects of the experimental treatments on weight gain and feed conversion ratio during the starter period, but there was a significant improvement in weight gain in grower, finisher and whole periods in chicks fed with diet containing 1000 mg/kg peptides (p < 0.05). Adding peptides improved intestinal morphology (in duodenum and ileum) (p < 0.05). Supplementation of casein peptides significantly reduced thiobarbituric acid reactive substances concentration in breast and thigh meat. The activity of amylase, lipase and protease enzymes improved in treatments containing 800 and 1000 mg peptides in comparison to the control treatment. The use of casein-peptides increased intestinal Lactobacillus and decreased Coliform populations.