Effect of Qualitative Feed Restriction and Duration of its Application on Performance, Blood Biochemical Parameters, and Carcass Characteristics of Broiler Chickens

In the present research, decrease of dietary nutrients concentration and duration of its using were investigated on performance of broiler chicken. A total of 375 one-day-old male broiler chickens were used in 5 treatments and 5 replicates per treatment of 15 birds per each from 1 to 39 d. In the present study, “normal” diet is referred to a diet based on recommended requirements of broiler chicken strain, and “diluted” diet is referred to a diet diluted 7% for energy and essential amino acids. Experimental diets (respectively, for starter, grower and finisher periods) in the treatments were: T1) normal, normal, normal (control); T2) diluted, diluted, diluted; T3) normal, diluted, normal; T4) diluted, diluted, normal; and T5) normal, normal, diluted. In the whole period (1 to 39 d of age), daily feed intake (p<0.05) and daily weight gain (p<0.01) of control were greater than other treatments. Feed conversion ratio did not show a significant difference among treatments. In the finisher period, mortality was greater in control than T2 and T3 (p<0.05); however, in the whole period, there was no significant difference among treatments. Breast weight was greater in control and T3 than T2, T4 and T5 (p<0.01). The T2 and T3 had the greater bone ash than control and T5 (p<0.05). In general, using the normal diet through the whole period showed the best growth performance, although this treatment revealed the increased mortality and decreased bone ash during finisher period.