Effect of protease supplementation on the performance and digestibility of broilers

Abstract

Premise of the study was to validate the growth promoting eff ect of protease on the performance and to explore its digestion enhancer eff ect in broiler chicks. For this purpose 4 commercial diets were divided into two types (low and high density) and were enriched with protease using a completely randomized design with 4 replicates per diet having 10 chicks each having totaled 200 poultry broiler chickens (day-old). Until 14 days, no eff ects were observed on chicks however at day 14; little variations were observed on weight gain, feed intake and FCR (feed conversion ratio) among the enzyme enriched diets. At day 28, prominent response of protease supplementation in low protein was procured. The chicks gained 10.06 and 8.0 % more weight on CFP1 than CFG1 and CFG2, respectively. Similar response in FCR was observed and was found to be 0.20 and 0.15 points better on CFP1 than on CFG1 and CFG2, respectively. However, CFP2 failed to show protease effi cacy declining the weight gain by 23.01 % while the FCR by 0.49 points as compared with CFP1. This suggested that the nature of feed ingredients in the diets is important for obtaining maximum benefi t of protease supplementation. The overall performance indicated signifi cant response to enzyme supplemented diets. Among the low protein diets CP digestibility remained unchanged but they were diff erent in sparing AME (apparent metabolizable energy) for chicks. The CFP2 spared 98.21 kcal/Kg more AME than CFP1. However, this increased AME values did not help to boost the performance and was attributed to the widening ratio between CP and AME. These results demonstrated that the overall growth response of chicks was improved on low protein diet enriched with protease. It showed higher CP digestibility and AME values than good quality diets. However, the inconsistent results observed within the two types of diets revealed that the nature of diets might have infl uenced the effi cacy of protease.