EFFECT OF DIFFERENT LEVELS OF ENERGY ON THE DIET DURING DIFFERENT AGE ON PRODUCTIVE PERFORMANCE OF BROILER

This study was conducted in the poultry field of the Department of Animal Production/ College of Agriculture/ University of Anbar, from 28/10/2021 to 8/12/2021. A total of 192 unsexed, one day, 40 gm of Ross 308 broiler were used, the chicks were randomly distributed to 4 treatments with 4 replicates for each treatment (12 chicks per replicate), the treatments were as follow: T1 (control): The energy level was 3001.5, 3103 and 3151 kilo calorie per 1 kg of diet for starter, grower and finisher respectively. T2: The energy level was 3149, 3231 and 3340 kilo calorie per 1 kg of diet for starter, grower and finisher respectively. Treatment T3: The he energy level was 2850.5, 2950 and 3151 kilo calorie per 1 kg of diet for starter, grower and finisher respectively. Treatment T4: The energy level was 2850.5, 2950 and 3205 kilo calorie per 1 kg of diet for starter, grower and finisher respectively. The results of the study concluded that the use of different levels of energy in the diets did not have any significant effect at (P≤0.05) on some characteristics of the productive performance of broilers. (P≤0.05) in the second week, where the second treatment outperformed the fourth treatment. As for the fourth week, the first and third treatments were significantly superior at (P≤0.05) over the fourth treatment. In the fifth week, the first, second and third treatment were significantly superior to the fourth treatment at (P≤0.05), as well as the weight gain, where a significant difference occurred in the second week, where the second treatment was significantly superior to the fourth treatment at (P≤0.05). As well as the third week, the first and third treatment were significantly superior to the second treatment at (P≤0.05). As for the relative growth rate, a significant difference occurred only in the third week, where the first, third and fourth treatment were significantly superior to the second treatment at (P≤0.05). As for the use of different levels of energy during the growth period, it had no effect on the characteristics of the carcass except for the weight of the chest, where the first, second and third treatments were significantly superior at (P≤0.05) over the fourth treatment.