Effect of increasing β-mannanase supplementation in diets containing copra meal on growth performance, meat quality, liver health, intestinal morphology, and nutrient utilization in broiler chickens

The current study aimed to investigate the effect of increasing β-mannanase supplementation in diets containing copra meal (CM) on growth performance, meat quality, liver health, intestinal morphology, and nutrient utilization in broiler chickens. A total of 1,600 3-d-old Ross 308 broiler chickens (initial body weight±standard deviation = 43.3±1.08 g) were randomly allotted to 1 of 5 treatment groups with 8 replicates. One group was fed a corn-soybean meal-based diet (control). Other 4 diets were prepared by inclusion of 10% commercial CM in the control diet with 0, 400, 800, and 1,600 U β-mannanase/kg. Experiments lasted for 32 d. Birds fed the control diet had less (p = 0.001) feed conversion ratio (FCR) than those fed diets containing 10% CM without β-mannanase supplementation. Increasing supplementation of β-mannanase in diets containing 10% CM had no linear and quadratic effects on body weight gain, feed intake, and FCR in broiler chickens. The control diet had greater (p