Four hundred and fifty one-day Cobb broiler chicken were used to investigate the effect of partial replacement with wheat grain without or with different commercial enzyme products supplementation on growth performance, immune response, blood serum parameters and some carcass characteristics. Broiler chicken were allotted into 9 equal groups (50 chicks of mixed sex per group). Three experimental diet were formulated but the 25% or 50% corn of the basal diet was replaced by wheat grain (w/w) and the diet adjust to be iso-nitrogenous and iso-caloric diets, each diet supplemented by Kemzyme plus dry or by Combozyme (enzyme blend commercial products) to be 9 experimental groups. The experimental period continued for six continuous weeks. It was observed that wheat inclusion at 25% instead of corn non significantly reduced body weight and gain of broiler chicken, while 50% replacement improved both parameters when compared with chick group fed on corn-soybean based diet. However, it was observed that wheat inclusion at 25 or 50% instead of corn grain in broiler chicken ration increased feed intake by about 1.3% and 9.8% respectively and consequently deteriorate FCR, PER, EEU and PI by about (4.6% and 4.6%), (8.2% and 6.5%), (4.9% and 4.0%) and (13.7% and (4.2%) respectively when compared with broiler chicken group fed on corn soybean based diet. Moreover, enzyme supplementation in 25% wheat containing diet increased feed intake but, with 50% wheat inclusion decreased feed intake also, enzyme supplementation in wheat included ration improved FCR, PER, EEU and PI when compared with broiler chick group fed on the same diet without enzyme supplementation. On the other hand, wheat inclusion had no significant effect on blood serum total protein, albumin, globulin and glucose concentrations, while reduced blood serum triglycerides and cholesterol concentrations, also wheat inclusion in the broiler chicken diet had determinately effect on liver function through elevation of some blood serum enzymes when compared with chick group fed on corn-soybean based diet. Regarding immune response, it was observed that wheat inclusion instead of corn reduced phagocytic activity and index, and reduce antibody production against NDV while enzyme supplementation improve the health status of broiler chicken when compared with broiler chicken group fed on the same diet without enzyme supplementation. It was observed that both wheat grain inclusion without or with enzyme supplementation had no significant effect on carcass traits of broiler traits and the most prominent effect was leading to reduction of abdominal fat weight and relative weight and improve thymus gland weight of broiler chicks.
Key words: Broiler chicken Wheat grain Enzyme supplementation growth performance Immune response carcass traits.