EFFECT OF WEIGHT CHICKS AT THE AGE OF 7 DAYS ON PRODUCTIVE PERFORMANCE FOR BROILER CHICKENS ROSS 308

Abstract

Abstract: Used 180 of chicks meat strain Ross 308 , Belgian origin , unsexual were selected randomly and fed free on one diet for the duration of the experiment of 35 days , and after recording the weights of chicks and weight of the feed intake for the one chick at the age of 7 days, chicks were divided according to the weights into three groups : the first group T1 ( less than 180 g ), the second group T2 (180 - 200 g ) Group, third group T3 ( higher than 200 g ) . Each group contained two replicates , using 30 birds / replicate .. for the purpose of studying the effect of chicks weight at the age of 7 days at rates of body weight , increase the weight , feed intake , feed conversion ratio , mortality percentage , dressing percentage . At the end of the experiment 6 birds were slaughtered from each group, it was a study carcass weight , the weight of major and minor cuts (breast , back, thighs , wings and neck ) , the weight of some internal organs (heart , liver and gizzard ) and weight of abdominal fat . Results showed Significant differences (p <0.05) in the rate of body weight, increase the weight between bird groups T1, T2, T3, birds in group T3 has shown significant superiority( p <0.05) in these two qualities compared with group T1 at the age of 3 weeks. Significant differences (p <0.05) in body weight, increase the weight between birds groups, T1, T2, T3 at the age of 5 weeks. Significant Superiority ( p <0.05 ) in feed consumption rate for birds in group T2, T3, compared with the group T1 at the age of 3 weeks, and despite the increase in the rate of feed intake in birds in groups T1, T2, T3 at the age of 5 weeks by the increase weight of the chicks at the age of 7 days, but the results of statistical analysis showed a non-significant differences in these characteristics between the three groups at the end of the experimental period of 35 days . Despite the improvement in feed conversion ratio at the age of 3 weeks by increase of chicks weight at the age of 7 days, but the differences were not significant between the three groups of birds, while the results showed significant differences (p <0.05) in feed conversion ratio in birds age of 5 weeks whenever chicks highest weight at the age of 7 days between the three groups T1, T2 , T3 . Mortality did not show significant differences at the age of 3 and 5 weeks of birds among the three groups .Significant differences (p <0.05) in the rate of carcass weight free of viscera, chest piece, piece of the back and neck weight with the weight of the birds by the increase weight of chicks at the age of 7 days. In spite of the improved dressing percentage, average thighs weight, the weight of the wings, the weight of the heart, gizzard, liver and abdominal fat weight, but the differences were not significant in these traits among bird groups in this study .