Effect of differents dietary relationship metabolizable energy: crude protein and the initial weight of chicks on the performance and yield of carcass in females broilers

Abstract

This study was accomplished to verify the effect of the differents dietary relationship metabolizable energy:crude protein and the initial weight of chicks on the performance and yield of carcass in broilers. There were used 640 female chickens of the commercial ancestry (Cobb). A completely randomized trial was applied, in factorial outline 2x2, with two levels of chicksâ weight (38g and 46g) and two levels of relationship ME:CP (High - 149,8; 174,4 e; 194,4 and, Low - 130,0; 150,0 e; 166,7, for the initial, growth and end ration, respectively), totalizing 4 treatments, each one of them with 4 repetitions of 40 chicks, ranging until 48 days of age. There were evaluated the Feed Intake (FI), Weight Gain (WG), Feed Conversion (FC) and Mortality, during all the experimental period and, performance and chemical composition of carcass in the end of the experimental period. There was no significant difference (P>;0,05) in feed intake and weight gain in the tested treatments. However, there was significant difference (P<0,05) at the FC, when the broilers were fed with Low Relationship ME:CP ration and showed the worst result, independent of the initial weight, during the 1 to 35 days of age. In the composition of carcass there was significant effect (P<0,05), where the high initial weight broilers fed with High Relationship ME:CP ration showed better results.