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.

Abstract

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 [BW] ± SD = 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<0.01) apparent total tract retention (ATTR) of DM, GE, and N as compared to the diets containing 10% CM without β-mannanase supplementation; however, no differences in the ATTR of Ca and P were identified between 2 diets. There were no linear and quadratic effects of increasing supplementation of β-mannanase on the ATTR of DM, GE, N, Ca, and P in broiler diets containing 10% CM. Both inclusion of 10% CM and increasing supplementation of β-mannanase in broiler diets did not affect apparent ME (AME) and N-corrected ME (AMEn) values in treatment diets. The use of 10% CM in broiler diets during growing and finishing period impairs growth performance by decreasing energy and nutrient utilization in diets. Increasing β-mannanase supplementation in diets containing 10% CM has no positive effects on performance, meat quality, liver health, intestinal morphology, and nutrient utilization in broiler chickens.