Effects of a multi-enzyme on performance and carcass characteristics of broiler chickens fed corn-soybean meal basal diets with different metabolizable energy levels

摘要

A 4 ???? 3 factorial experiment was designed to study the effects of a multi-enzyme (Avizyme 1502; combination of xylanase, ???±-amylase and protease) in three levels (0, 250, 500 mg/kg) on performance and carcass characteristics of broiler chickens fed corn-soybean meal diets with different levels of metabolizable energy (ME; 13.18; 12.34; 11.93 and 11.51 MJ/kg) from 1 to 49 days of age. Results showed that dietary treatments had no significant effect ( P > 0.05) on feed intake at 10 days and 24 days but birds fed diets containing 13.18 MJ/kg ME with 500 mg/kg multi-enzyme consumed more feed than birds fed diets with 11.51 MJ/kg ME and 250 mg/kg multi-enzyme ( P < 0.05) at 49 days. Average daily gain in starter (1?￠????10 days) and finisher (25?￠????49 days) periods was affected by interaction between ME and enzyme. No significant differences ( P > 0.05) were observed for feed conversion ratio (FCR) in grower period, although dietary treatments affected FCR in starter and finisher phases. At 49 days of age, the best FCR obtained for birds fed diets containing 13.18 MJ/kg ME and 250 mg/kg multi-enzyme. The highest FCR was for birds fed a diet with 11.51 MJ/kg ME with 250 mg/kg multi-enzyme. Breast, thigh and liver were significantly affected by dietary treatments. A diet with 13.18 MJ/kg ME and 500 mg/kg multi-enzyme resulted in the highest breast and thigh yield ( P < 0.05). It can be concluded that adding enzymes to corn-soy based diets allowed the reduction in the energy level of broiler diets without any negative effects on performance of broiler chickens.