Dietary supplementation of β-Mannanase on growth performance, nutrient retention and economics of Broilers fed with low energy

Six-week experiment was undertaken to evaluate β-mannanase supplementation in low-energy broiler diets. A total 300, day-old Cobb-430Y broiler chicks were assigned to five groups, containing 60 chicks with three replicates of 20 in each. The group PC was the positive control and contained 3000, 3125, 3250 kcal ME/kg feed in the pre-starter, starter, and finisher phases, respectively. Negative controls (NC1 and NC2) had 75 and 100 kcal less ME/kg diet, respectively, than PC. The 100g/ton β-mannanase (Natupulse^® TS) was supplemented in these negative controls forming groups NC1+BM and NC2+BM. The growth parameters (BW, WG, FI, and FCR) were measured at a weekly interval, and the carcass parameters and economics were assessed at sixth week age. The metabolic trial was conducted during the sixth week to measure nutrient retention. Results found that the negative controls low-energy diets (NC1 and NC2) depressed (P ≤ 0.05) broiler growth while β-mannanase addition (NC1+BM and NC2+BM) improved (P ≤ 0.05) BW, WG and FCR with less FI with higher net profit achieving the best in NC1+BM group. The β-mannanase addition improved giblet (P ≤ 0.01) and dressed yield (P ≤ 0.05), and increased (P ≤ 0.01) retention of Dry Matter, Nitrogen, Ether Extract, Total Ash, Nitrogen Free Extract, and Apparent Metabolizable Energy, particularly in NC1+BM group. It was concluded that the addition of β-mannanase at 100g/ton in a diet containing 75 kcal low energy was found to be more beneficial and economical than a 100 kcal low energy diet.