Author : Duong Duy Dong

Summary : Two hundred eight (208) individually caged 24-week old pullets were used in two experiments. In the first, 160 pullets were used to evaluate the effect of enzyme supplementation of corn-based diet at two levels of nutrient densities. Pullets were randomly assigned to four dietary treatment following a factorial arrangement (2x2) in a completely randomized design with 40 replications. In the second experiment, 48 pullets were used to evaluate the effect of three kinds of commercial enzyme preparation on the performance of layers fed wheat-based diet. The birds were randomly allocated to four treatments following a completely randomized design. Each treatment was replicated 12 times with an individual caged layer each. Results on experiment 1 showed no significant interaction between nutrient density and enzyme supplementation on all the parameters considered. BAsed on the overall average, pullets fed high nutrient density diets had higher (P<0.05) egg production rate than those fed low nutrient density diets. Enzyme supplementation of the diets improved (P<0.05) the overall egg production and feed efficiency of the pullets. The other parameters were not significantly influenced by either the nutrient density or enzyme supplementation of the diets. Enzyme supplementation of low nutrient density diets increased the income over feed cost (IOFC) of the pullets. In contrast, similar supplementation of high nutrient density diets with the enzyme showed negligible effect on IOFC of the pullets. The results in experiment 2 showed a significant improvement in egg production rate, and income over feed cost of pullets fed wheat-based diets supplemented with different enzyme preparations. Enzyme supplementation did not improve the egg weight, feed consumption, feed efficiency of the pullets. the yolk color scores, egg shell thickness as well as the body weight gain of the pullets were not affected by enzyme supplementation of the diets.