Effect of Grower Dietary Energy Level on Feed Intake and Performance of Modern Broiler Chickens

An experiment was carried out to investigate the effect of dietary energy levels on feed intake of modern broiler chickens during the growth period. A total of 160 Ross broiler chicks (mixed sex) in a completely randomized design with 4 treatments and 4 replicates (10 birds) were used. The chicks were fed from 11 to 24 days of age with dietary treatments, including 4 grower diets with 2800, 2900, 3000, and 3100 kcal/kg ME and constant nutrient to ME ratios. All chicks were fed the recommended Ross diet during starter (1- 10 days) and finisher (25-42 days) periods. At the end of experiment period (42 days), growth performance and carcass characteristics were measured. The results showed that the energy level had no significant effect on the average daily feed intake for the grower period, but the grower's dietary energy level had a significant effect on daily body weight gain and feed conversion ratio. Also, there was no significant difference in final live weight and relative carcass yield at the end of the experimental period. In conclusion, during the growing period, modern broiler chicks consume feed regardless of the energy level of the diet and continue up to physical satiety.