Effect of a novel alkaline protease from Bacillus licheniformis on growth performance, carcass characteristics, meat quality, antioxidant capacity, and intestinal morphology of white feather broilers

BACKGROUND: The present study was conducted to investigate the effects of dietary novel alkaline protease from Bacillus licheniformis on the growth performance, meat quality, antioxidant status and intestinal morphology of broilers. In total, 4000 broilers were randomly assigned into five groups and treated with normal control, normal control + 100 mg kg(-1) protease, normal control + 200 mg kg(-1) protease, normal control + 300 mg kg(-1) protease and normal control + 400 mg kg(-1) protease. RESULTS: Supplementing protease impacted final body weight (linear, P = 0.003; quadratic, P = 0.006) and decreased feed conversion rate (linear, P = 0.036) in broilers. Moreover, dietary protease significantly increased breast muscle rate (linear, P = 0.005; quadratic, P = 0.021) and decreased drip loss (linear, P < 0.001; quadratic, P < 0.001). In addition, dietary protease notably increased protein digestibility (linear, P = 0.001; quadratic, P = 0.006) and trypsin activity (linear, P = 0.002; quadratic, P = 0.009) in jejunum. Light microscopy revealed that the jejunum villi in the 300 mg kg(-1) and 400 mg kg(-1) groups exhibited greater height and a denser arrangement compared to those in the control group. The addition of protease decreased malondialdehyde content (linear, P < 0.001; quadratic, P < 0.001) and increased total antioxidant capacity (linear, P = 0.001; quadratic, P < 0.001) in pectoral muscles. CONCLUSION: The results of the present study suggest that dietary novel alkaline protease from B. licheniformis improved growth performance by affecting trypsin activity, protein digestibility, antioxidant capacity and intestinal health. (c) 2024 Society of Chemical Industry.