Evaluation the effects of changing time of starter, grower and finisher feeding periods on performance and carcasses quality of broilers

This experiment was conducted to evaluate the effects of changing time of starter, grower and finisher feeding periods on performance and carcasses quality of broilers in a completely randomized design. Six hundred and thirty Ross- 308 strain of broiler were randomly assigned to 7 dietary treatments with three replicate and thirty bird in each replicate and investigated for eight weeks in three different feeding periods. In control group feeding periods were feeding periods those recommended by NRC. Other 6 treatments included: S17G42F56, S25G38F56, S17G42F62, S25G42F52, S21G46F52, S21G38F56. At the end of experiment period the results showed that there were significantly difference between treatments in performance and carcasses quality (P0.05). There was significantly difference between treatments about average daily feed intake (P0.05). High amount of average daily feed intake (111.55 g) was observed in 3 experimental group. Average daily weight gain was significantly difference between treatments (P0.05). High amount of average daily weight gain (57.17 g) was observed in 7 experimental group. There was significantly difference between treatments about average final live weight (P0.05). High amount of live weight (3250 g) was observed in 7 experimental group. There were not any significantly difference among experimental groups in feed conversion and feed price (P0.05). However better feed conversion (1. 82 g: g) and low price of feed intake fir obtaining per kilogram of live weight (438 Toman/kg) were observed in 7 experimental group. Carcasses traits were significantly affected by different feeding periods (P0.05). There were significantly difference between treatments in breast meat percent (P0.05). High percent of breast meat (36.36) was observed in 2 experimental group. There were significantly difference between treatments in thigh percent (P0.05). High amount of thigh percent (32.48) was observed in 7 experimental group. The overall results of the present study indicate that in broiler with using the feeding periods like 7 experimental group, the improvement of performance and carcasses traits and reducing feed price is possible.