Metabolism and Nutrition–enzymes 357p the Effects of Different Enzyme Complexes on Nutrient Digestibility, Performance, and Processing Yield in Male Broil

The efficiency of 2 enzyme complexes on male broiler nutrient digestibility and performance were evaluated. A total of 120 and 840 day-old male broilers (Cobb 500 strain) were used in the metabolic and performance tests, respectively. The birds were distributed into 4 treatments [positive control (PC), negative control (NC), NC + enzyme complex A (xylanase, glucanase, amylase, protease and cellulase) and NC + enzyme complex B (xylanase and β-glucanase)]. In the metabolic test, 24 excreta collecting cages were utilized. The birds were caged from 14 to 21 d of age (doa) in which 3 d were for adaptation and 4 d for total excreta collection (the method of total excreta collection included the removal of feathers and spilled feed in the tray). The birds in the performance test were randomly allocated to 24 floor pens. The feeding programs were divided into 3 phases: starter (1 to 21 doa), grower (22 to 35 doa), and finisher (36 to 42 doa). Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) were measured at the end of each dietary phase. Processing yield was determined at 42 doa. The data were subjected to ANOVA and SNK test analyses. Significance was accepted at P < 0.05. In the metabolic test, there were no significant treatments differences for any of the parameters evaluated (dry matter, apparent digestibilities of CP and fat, and AMEn). No significant treatments effects were observed for the above parameters during the starter and grower phases or for carcass, drumstick, and breast yields. During the finisher phase, the PC exhibited superior FCR and WG results in comparison to all other treatments. For the whole experimental period (1 to 42 doa), the WG of birds receiving enzymatic complex B was similar those in the NC group. Birds belonging to the PC group had a more efficient FCR in comparison to the NC group. Enzyme complex A helped male broilers to more efficiently recover nutrients from their diets than did enzyme complex B. Nevertheless, the treatment effects on performance were not mobilized by changes in the metabolic parameters evaluated.