An experiment was conducted to determine the effect of dietary supplementation of two Cu sources: inorganic (copper sulfate) and organic (copper yeast) with different levels of metabolizable energy on productive performance of broiler chickens. Three dietary metabolizable energy levels were used in starter period from 1 to 28 days old (2900, 2800 and 3000 kcal/kg); the corresponding values in finisher period (29 to 42 days old) were 3000, 2900 and 3100 kcal/kg, respectively. One-day-old Cobb broiler chicks were randomly assigned into nine experimental groups, each with three replicate groups. Diets containing 2900 and 3000 kcal ME were used as controls for the starter and finisher periods, respectively. In the starter diets (2800 and 3000 kcal ME/kg) Cu was supplemented at 50 and 100 mg/kg as copper yeast and at 50 and 100 mg/kg as copper sulfate. In the finisher diets (2900 and 3100 kcal ME/kg) the same sources and levels of Cu were added. During the whole experimental period, dietary supplementation with organic and inorganic copper caused a significant increase in LBW of birds compared with their controls. Birds fed the high ME diets plus Cu yeast consumed significantly less feed compared with the control group, but chicks fed the low ME diets plus copper consumed approximately similar amounts of feed compared with the control. Birds fed the high ME diets plus organic or inorganic copper displayed significantly better FCR than the control. Dietary Cu supplementation had no significant effect on carcass yield of broilers, expect those fed the high ME diet plus 100 ppm Cu yeast which exhibited significantly higher carcass yield compared with their control group. Birds fed the low ME diets plus 50 ppm Cu yeast or 100 ppm CuSO4 and those fed the high ME diets plus 100 ppm Cu yeast and those given diets plus 50 or 100 ppm CuSO4 displayed significantly higher total edible parts compared with the control group. Broiler fed diets containing the high ME diets supplemented with 50 or 100 mg/kg organic copper had higher means of net revenue and economic efficiency compared with the control birds. It can be concluded that birds fed the high ME diets plus 100 ppm organic copper can improve productive performance of broilers.

n experiment was conducted to investigate the effect of xylanase supplemented diet by its role to remove anti-nutritive effect of non-starch polysaccharide (NSP) is well established and optimizing the ME utilization. A total of 315, one-day-old unsexed Cobb broiler chicks, were randomly assigned into seven experimental groups of 3 replicates each with 15 birds in each replicate. The chicks were offered corn-soybean meal basal mash diets that was prepared to contain 3000 kcal ME/kg and 23% crud protein during starter period till 21 days of age, followed by 3100 kcal ME/kg and 21% crud protein during grower period till 35 days of age, and 3200 kcal ME/kg and 19% crud protein during grower period till 42 days of age. One of the seven experimental groups was fed this diet as such to serve as control while, the remaining six groups were fed the lowered ME levels by 150 or 300 kcal compared basal diet and supplemented with 0,100 and 200 mg xylanase/kg diet during starter, grower, and finisher periods, respectively. The obtained results revealed that the highest (P<0.05) body weight and weight gain recorded of birds fed dietary T3 compared to control group. Birds fed dietary T3 and control group consumed approximately similar amounts of feed and recorded a significantly better feed conversion ratio (FCR) than the control. Relative carcass weight yielded of broilers fed dietary treatment and control basal diet were statically (P< 0.05) similar, expect those fed dietary T4 recorded a significant lower value of carcass yield compared with either control or other treatment groups. Total edible parts were significantly heavier of birds fed xylanase-supplemented diets (T3, and T6) compared with that of the control and other groups. Birds fed dietary T3 recorded the highest (P< 0.05) value of relative thymus and spleen weight compared others. While, insignificant differences were observed of bursa among other treatments. The hematological parameters (Hb, PCV, RBCs and WBCs) were significantly (p≤ 0.01) improved of birds fed dietary T3 compared with counterparty of control. Total protein, albumin and globulin were significantly increased while, the concentration of triglycerides and cholesterol were significantly decreased of birds fed dietary T3 and T2 compared with the control group.