Prediction of body weight of broilers at different ages from linear body measurements

The prediction of live body weight from six body measurements was studied using the Cobb broiler strain. A total of two hundred and sixty four chicks comprising of one hundred and thirty four at males and females were used. Mean body weights day-old, 3, 6, 9, and 12 weeks of age were 36.7g, 276.16g, 856.72, 1,334.1g and 1,762g respectively for the sexes combined. Males were generally more uniform in body weight and the body measurements than the females as indicated by the lower coefficient of variability (2.53% vs 3.38% for body weight at 3 weeks of age). The males were slightly (P<0.05) heavier than the females at 9 and 12 weeks of age. Cumulative weight gain was more rapid between 3 and 6 weeks of age and decreased with age up to the 12th week. The correlations, linear and stepwise regression equations reveal linear relationships between body weight and all body measurements (Body length, Body girth, Keel length, Shank length, Drumstick length and Shank thickness). Live body weight of bird was best predicted singly using keel length at 3 and 9 weeks of age and body girth and the 12th week. However with a combination of two to four of the body measurements, the prediction efficiency was enhanced.