Growth Patterns of Body and Abdominal Fat Weights in Male Broiler Chickens

Male chickens from a purebred male broiler selection line were grown and slaughtered weekly from 1 to 69 days of age. The Gompertz equation was chosen to fit the data of live weight, carcass weight, abdominal fat weight, percentage abdominal fat of live weight, and percentage abdominal fat of carcass weight to investigate growth patterns. Twenty sires each provided a single progeny for each slaughter age. The Gompertz equation for this study was in the form: Wt=W0·e(L/K)·(1−e−kt) The predicted curves closely fitted the weight data points. The data points for both percentage fat curves showed a dip beginning at 20 to 27 days of age, probably because of starter ration fed up to 4 weeks of age. The peak gains per day were determined from the first derivative of the equation. The ages for the peak gains were: live body weight, 44 days; carcass weight, 45 days; abdominal fat weight, 43 days; percentage abdominal fat of live weight, 19 days; and percentage abdominal fat of carcass weight, 15 days. Growth rate of abdominal fat deposition was slower than live weight after 19 days and carcass weight after 15 days.