Effect of enzyme supplementation on metabolizable energy and apparent nitrogen retention in broiler diets based on corn- soybean meal

Supplementation of exogenous enzyme can improve mtabolisable energy of broiler chicken diets. This study was conducted to evaluate the effects of supplementation of exogenous enzyme on apparent DM and CP metabolizability, apparent N retention and improvement of AMEn of broiler chicken diets. A total of 200, one day old male broiler chicks were randomly assigned in completely randomized design, as 4×2×3 factorial arrangement (4×3×2) with 4 ME levels (2750, 2850, 2950 and 3050 kcal/kg) supplemented with 2 levels (0 and 450 mg/kg of diet) of an exogenous enzyme, Natuzyme –P, in diets of broilers on apparent DM metabolizability, apparent N retention and AMEn improvement over the starter, grower and finisher phases of growth. The apparent DM metabolizability of diets was increased by increasing AMEn levels (P<0001) and enzyme addition increased DM metabolizabilityby as much as 1.8 percent (P< 0.0002).The apparent N retention was increased significantly with increasing ME levels (P< 0.001). Enzyme supplementation improved apparent N retention of diets as much as 2.63 percent (P< 0.0001). The values of AMEn were improved by the main effects of ME levels and enzyme addition (P< 0.0001, P< 0.0027). Enzyme supplementation increased mean value of AMEn as much as 52 kcal/kg. Apparent N retention (P<0.0001) and apparent DM metabolizability (P<0.0007) was affected significantly by the main effect of phase growth and the highest values of apparent N retention and apparent DM metabolizability was found in grower and starter phases of growth, respectively. Two and three-way interaction effects of enzyme supplementation, ME levels and growth phase was not significant on AMEn improvement, apparent DM metabolizability and apparent N retention. Enzyme supplementation in corn-soybean meal based diet improved apparent DM metabolizability, apparent N retention and AMEn values.