The Effect of Quantitative Feed Restriction in Different Ages on Performance and Carcass Traits of Broilers Chicks

摘要

This experiment was conducted to investigate the effect of the physical limitations of feed in different ages on the performance, carcass characteristics and compensatory growth of broilers. Two hundred eighty day-old Ross 308 broiler chicks were used in a completely randomized design with 7 treatments, 4 replicates and 10 observations per each. The treatments consisted of SW, SW10, SW20, SW30, TW10, TW20 and TW30. The diet for SW treatment had no restriction [control], while those for treatments SW10, SW20 and SW30 were feed restricted to 90, 80, and 70%, respectively, of ad libitum intake of the control birds on the previous day, from 7-14 d and treatments TW10, TW20 and TW30 were feed restricted at same levels from 14-21 d, respectively. Feed intake [FI], daily weight gain [DWG], feed conversion ratio [FCR] were measured on days 1, 21 and 42 and final weight [FW], productive index [PI], feed cost [FC] and carcass characteristics were measured on day 42. Results indicated that FI, DWG and FCR were significantly affected by experimental treatments. In restricted diets FI decreased than that control diet [P <0.01]. DWG in restricted treatments was decreased and similar to control diet from 1-21d and 21-42d, respectively. FCR was improved in restricted diets than control diet [P <0.01] and was best in treatment SW30 than others from 1-42d. Between experimental diets, treatments SW20 and TW10 yielded FW similar to control diet. However, except treatments SW30 and TW30, other treatments improved PI than control diet [P <0.05]. In addition, FC was decreased in restricted diets than SW diet. As well as, there were no significant differences between treatment in carcass, thigh and pancreas percentage, however, breast, abdominal fat and gizzard weight were affected by experimental diets. Abdominal fat in restricted diets was decreased than control diet [P <0.01]. These results concluded that, quantitative restriction of feed decreased the feed cost and improved the productive parameters and carcass traits of broilers chicks.