Effects of enzyme inclusion in a maize–soybean diet on broiler performance

The aim of the current study was to formulate an environmentally-friendly diet through reducing nitrogen excretion by lowering protein levels in broiler production. This was done via inclusion of commercially available enzyme preparations; either a mixture of protease and carbohydrase (E-1) or a single protease (E-2), on a low crude protein maize–soybean meal broiler diet. Two experiments were repeated in two different seasons. Both enzyme supplementations increased feed intake for all diets in the cool season, but significantly decreased feed intake in the low-protein diet (LP) and increased in basal diet (BD) during the hot season. Broiler chickens in the enzyme-supplemented groups had better body weight gain as compared to those without supplementation, but only the E-2 supplementation improved feed conversion The enzyme E-2 supplementation, however, did not improve in vivo digestibility of the dry matter and protein, but significantly increased soybean meal hydrolysis rate and protein digestibility in the in vitro assay as compared to the respective ingredient without supplementation. Addition of either the single protease or the cocktail of protease and carbohydrase to a maize–soybean meal diet improved chicken growth.