초록
An experiment was conducted to evaluate the effects of dietary Kemzyme, phytase, yeast and a combination of Kemzyme, phytase and yeast (KPY) supplementation on the growth performance, nutrient utilizability and the nutrients excretion in broiler chicks. Experimental diets based on corn-soybean meal were supplemented with 0.05% Kemzyme, 0.1% phytase, 0.1% yeast, 0.25% KPY (0.05% Kemzyme + 0.1% phytase + 0.1% yeast), respectively. Each treatment had six replicates of six male birds each. A total of 180 Arbor Ares broiler chicks were fed these diets for a period of six weeks. Numerically better body weight gain was found in chicks fed Kemzyme, phytase, yeast of KPY supplemented diet. Feed conversion rate was improved by the addition of KPY compared with control group (p < 0.05). Mortality was successfully reduced by supplementation of enzymes, yeast or a combination of enzymes and yeast. The excretions of N and P were considerably reduced by supplementation of dietary enzymes, yeast or combination of all three substances, especially for KPY fed group in starting period. The nutrient excretions in the finishing period were not significantly different. It appeared that the use of Kemzyme, phytase and yeast simultaneously had an additive effect on growth rate and nutrient excretion.