This study was conducted to study the effect of
protease as well as three dietary crude
protein levels on growth and nutrient digestibility in broilers. The broiler chickens (n = 540) were assigned to six dietary treatments with six replicates. Three dietary crude
protein (CP) levels (17, 19, and 21%) along with two levels of
protease (0 and 30,000 IU/kg) were investigated in 3 × 2 factorial arrangement during the starter phase.
Body weight was higher (P < 0.05) in group fed with CP-21; however, feed intake was significantly (P < 0.05) lower in CP-19 and CP-21. Resultantly, FCR was significantly (P < 0.05) improved in birds fed with CP-21. Similarly,
body weight, feed intake, and FCR were significantly (P < 0.05) improved in
enzyme-treated birds compared to the untreated birds. For practical purpose, birds fed CP-19 with
protease enzyme resulted in improved FCR compared to birds fed with CP-21. The results revealed that CP and apparent metabolizable energy (
AME) were significantly (P < 0.05) higher in birds fed with CP-21 along with supplementation of
enzyme while abdominal fat was significantly (P < 0.05) lower in the same group compared to birds fed with CP-17. These results indicated that a diet having 21% CP supplemented with 30,000 IU/kg
protease enzyme was superior in improving the performance and digestibility of nutrients in broiler during the starter phase.