Effects of Enzyme Supplementation on Performance, Carcass characteristics, Carcass Composition and Some Blood Parameters of Broiler Chicken

Problem statement: Endogenous enzymes of broilers cannot adequately digest nonstarch polysaccharides and subsequently the ingestion of high levels of soluble NSP leads to increased digesta viscosity and reduced nutrient digestibility and absorption. Supplementation of NSPs degrading enzymes may remove the anti nutritive effects of NSPs and release some nutrients (starch, protein) from these elements. Therefore, in a completely randomized design the effects of a multi-enzyme (Endofeed W produced from Aspergillus niger, with minimum activity of 2250 u g⁻¹ xylanase and 700 u g⁻¹ β-glucanase) supplementation on performance, carcass characteristics, carcass composition and some blood parameters in Cobb 500 broilers fed on corn-soybean meal-wheat diets were studied. Approach: A total of 150 one-day-old broiler chicks (Cobb 500) were used in a completely randomized design with 2 treatments and 3 replicates. The main ingeridients of diets included corn, soybean meal and wheat. The enzyme levels added to the diets were 0.00 (control) and 500 mg kg⁻¹ DM. Results: Enzyme supplementation significantly improved relative growth, energy efficiency and protein efficiency from 11-28 days of age. Adding enzyme significantly decreased body weight gain, feed intake and improved feed to gain ratio, energy efficiency and protein efficiency from 29-44 days of age (p<0.05). Relative growth, energy efficiency and protein efficiency was increased and body weight gain, feed intake and feed to gain ratio was decreased by enzyme supplementation from 1-44 days (p<0.05). Enzyme addition significantly increased carcass and thighs + drumsticks percentages at 44 days of age. Adding enzyme significantly increased the concentration of blood Triiodothyronine (T3) at 28 and 44 days and reduced the concentration of blood Thyroxine (T4) at 44 days of age. Enzyme inclusion increased the concentration of blood total cholesterol at 10, 28 and 44 days of age, however triglyceride concentrations increased at 10 and 44 days (p<0.05). The concentration of blood uric acid was significantly decreased at 28 and 44 days in broilers fed enzyme supplemented diets. Conclusion: Results of this study indicated that supplementation diets with 500 mg kg⁻¹ multi-enzyme (Endofeed W) in corn-soybean meal-wheat based diet improved broiler chickens feed to gain ratio, carcass yield and it can change the concentrations of thyroid hormones and some metabolites in blood, but it had not significant effect on carcass composition.