EFFECT OF DIETARY ENERGY LEVELS WITH OR WITHOUT SELENIUM AND CHOLINE SUPPLEMENTATION ON PERFORMANCE OF BROILER CHICKENS

This research was conducted to study the impact of using two levels of ME (recommended (R) and     R-150 Kcal/Kg diet) and each with four type of addition (without Se or choline supplementation, 0.1 mg Se/Kg diet in the form of organic Se as Sel-Plex (Se yeast), 0.10% of choline and 0.05 mg Se/Kg diet + 0.05% choline in 2 x 4 factorial arrangement (giving eight dietary treatments) on growth performance of Cobb broiler chickens. Accordingly, a total number of 192 one-day old unsexed Cobb broiler chickens were firstly fed a control diet for five days. At six day of age, chicks were randomly allotted to the dietary treatments, birds were divided into eight treatments (24 birds each) and each treatment contained three replicates (eight birds each). Results obtained could be summarized in the following: Performance: Chicks fed diet containing recommended level of ME (R)-150 Kcal/Kg diet had significantly higher values of LBW at 41 days and LBWG, FI, GR, PI during the period from 6 to 41 days, while, chicks fed diet containing R had significantly lower values during the same previous periods. Chicks fed R-150 Kcal/Kg had the best FC, CPC and CCR during the period from 25 to 41 days, and those fed R-150 Kcal/Kg had the best CCR during the period from 6 to 41 days. Type of addition and interaction due to level of ME effect X type of addition (experimental treatments) had insignificant effect on LBW, LBWG, FC, CPC, CCR, GR and PI during the periods from 25 to 41 and 6 to 41 days (finisher and over all experimental period). Chicks fed diet containing R with 0.05 mg Se/Kg diet and 0.05% choline had higher value of FI during the period from 6 to 41 days. Slaughter parameters% and blood constituents: neither level of ME, type of addition nor interaction due to level of ME effect X type of addition had any significant effect on slaughter parameters% and blood constituents except, type of addition with dressing% and bursa, which was significantly affected. Chicks fed diet containing 0.1 mg Se/Kg diet as Sel-Plex had higher value of dressing percentage. Also, interaction due to level of ME effect X type of addition, which was significantly affected of total leucocytes. Chicks fed diet containing R-150 Kcal/Kg diet with 0.1% choline had higher value of total leucocytes at the end of the experiment. GSH-PX activity were significantly (P≤0.01) affected by level of ME and type of addition, chicks fed 0.1 mg Se/Kg diet as Sel-Plex had higher value of GSH-PX at 41 days. Chemical composition of broiler meat: Level of ME, type of addition and interaction due to level of ME effect X type of addition had insignificant effect on chemical composition of broiler meat, except, moisture %, which was significantly affected. Economic efficiency (EEf): EEf values during the period from 6 to 41 days of age improved in chicks fed all experimental diets, except, chicks fed diet containing recommended level of ME with 0.05 mg Se/Kg diet as Sel-Plex plus 0.05% choline (the lowest corresponding values, being 0.126 and 95.74%, respectively), as compared with those fed the control diet. Chicks fed diet 7 (R-150 Kcal/Kg diet plus 0.1% choline) had the best Economic and relative efficiency values being 0.251 and 191.34%, respectively. It would be concluded that: It can be concluded that, dietary ME can be reduced from the recommended level up to 150 Kcal/Kg diet and supplement these diets with 0.1 mg Se/Kg diet as Sel-Plex or/and 0.1% choline without affecting Cobb broiler performance.