A total of 180 straight-run day-old broiler chicks (Minerva Strain) were used to evaluate the performance of broilers fed with enzyme-supplemented diets. This was aimed to compare the efficacy of four enzyme preparations on broiler performance and carcass yield; and, to evaluate the economy of four enzyme preparations in broiler diets. Six treatments consisting of the following: 1) T1 - positive control, conventional broiler diet; 2) T2 - fibrous diet with Finzyme®; 3) T3 - fibrous diet with Natugrain®; 4) T4 - fibrous diet with Polyzyme Mg®; T5 - fibrous diet with Optizyme P5®; and, T6 - fibrous diet without enzyme, were randomly assigned following a Randomized Complete Block Design. Each treatment was replicated thrice, with each replicate having ten (10) birds.

Supplementation of the basal diet with commercial enzyme preparations gave comparable results with that of the control based on the average weekly gain in body weight, total gain in weight, feed consumption, dressing percentage with or without giblets, and weight of abdominal fat, liver and pancreas. Significant findings were seen in the feed conversion ratio and cost of feed per kilogram gain in body weight. Feed conversion ratios were significantly better in broiler diets supplemented with enzymes and in the positive control while the negative control required the higher amount of feeds to convert kilogram of meat. In terms of the average cost of feed per kilogram gain in weight, fibrous diets with enzyme supplementation were cheaper compared with the negative control while only T4 cost a little more than the positive control by P0.06. For the income over feed cost, T2 and T5 gave the highest income followed closely by the positive control (T1}) then by T3 and T4 Again the negative control gave the lowest income.

Thesis (Master of Science - Animal Science)

Includes appendices and bibliographical references