Effects of enzymes in diets with varying energy levels on growth and egg production performance of Japanese quail

The present study was conducted to evaluate the effect of feed-grade enzyme supplementation in diets with varying levels of energy on the performance of growing and laying Japanese quails. Day-old Japanese quails, 504 in number, were subjected to six dietary treatments with six replicates at each treatment. Each replicate had 14 chicks. The dietary treatments consisted of three energy levels ie 12.15 MJ (2900 kcal), 11.30 MJ (2700 kcal) and 10.48 MJ (2500 kcal) ME kg-1 diet and two enzyme levels (0 and 0.5 g kg-1 diet). A metabolism trial was conducted at the fourth week of age. At the end of week 5, 10 quails (five of each sex) per treatment were sacrificed for carcass characteristics and 20 female quails from each of the six dietary groups were housed in individual laying cages and fed respective layer diet to study the laying performance and egg quality up to 20 weeks of age. Body weight gains of quails fed 12.15 MJ or 11.30 MJ ME kg-1 diets were significantly higher (p < 0.01) than those fed diets with 10.46 MJ ME kg-1 diet. Feed intake was significantly lower (p < 0.01) in birds that received diet with 12.15 MJ ME kg-1 than in birds that diets containing either 11.30 or 10.46 MJ ME kg-1 diet. Feed conversion ratio (p < 0.01) was best at 12.15, followed by 11.30 and 10.46 MJ ME kg-1 diet. Enzyme supplementation did not improve the growth performance, feed intake or feed conversion efficiency of quails. Enzyme addition also did not influence nitrogen retention or energy or dry matter metabolizability. The carcass characteristics did not differ because of energy or enzyme supplementation. Feed intake increased significantly (p < 0.01) as the dietary energy level decreased. The egg production and quality characteristics remained almost similar in all the dietary treatments. It was concluded that the optimum dietary energy level for quail was 12.15 MJ (2900 kcal) ME kg-1 during the growing phase and 11.30 MJ (2700 kcal) ME kg-1 during the laying phase. Addition of feed enzymes to conventional diets containing varying levels of maize, soyabean meal, fish meal and deoiled rice bran was not beneficial to improve growth, carcass traits, egg production performance or nutrient utilization.