Effect of exogenous protease on growth performance and meat quality in broilers reared on fishmeal-based diets

This study determined the effect of protease supplementation in fishmeal-based diets on growth performance and meat quality of commercial broiler birds. Four hundred and thirty-two (432) day-old broiler chicks were divided into 36 experimental units of 12 chicks each. Nine experimental diets were formulated using three levels (0%, 25%, and 50%) of the fishmeal as protein source, on protein equivalent basis, with or without alkaline protease (CIBENZA[R] DP100), and with overestimation of nutritional value based on the enhanced digestibility coefficient (EDC) concept because of the use of alkaline protease. Feed consumption and bodyweight were measured weekly. On the last day of the trial, two birds from each pen were picked and processed for carcass and meat quality parameters. Data were analysed by analysis of variance in a 3 x 3 factorial arrangement of completely randomized design. Weight gain and feed conversion ratio (FCR) were improved in the birds with 25% fishmeal as a replacement for soybean meal (SBM) and enzyme supplementation. Similarly, higher protein digestibility, dressing percentage and thigh meat yield were observed in birds fed diets with 25% fishmeal with added enzyme. In the blood biochemical profile, uric acid levels were lower, and cholesterol and triglyceride were higher in the group fed diets with 25% fishmeal with EDC and enzyme. The addition of protease enzyme to the diet with 25% fishmeal improved growth performance, crude protein digestibility and carcass characteristics. Keywords: complete blood count, enzyme, enhanced digestibility coefficient, soybean meal, serum biochemistry