The objective of this study was the evaluation of the use of different measures as predictors of breast weight. Thirty-two Anak chicks and 32 Ross chicks were used for the experiment 1. They were randomly sampled from two populations of 400 broilers of each genotype. A slaughter followed by dissection of commercial cuts was done at 53 days old. The following weights were recorded: live weight (PV), eviscerated carcass (PC), and breast (Pch). Proportions to live weight were also used (%PC, %Pch). Breast height and length were measured with calipers previously to the slaughter. Differences between genotypes were found for PV, PC, %PC, Pch and %Pch (p< 0.05). The Ross broilers were heavier than the Anak ones, as theirs carcasses, breasts and proportions were higher. Pch was high correlated with PV, and the calipers measurements did not improve the prediction of Pch and %Pch. Sixty INTA-Campero broilers, randomly sampled from 100, were used for the experiment 2 up to 69 days old. At that age in vivo calipers measures were taken from the length and height of the breast, and ultrasound was used for depth of breast measure. The measured characters at slaughter were the same as those of the experiment 1. An appropriate prediction of Pch was obtained using PV, breast length and breast depth (R²=0,75). The elimination of the ultrasound measurement did not reduce the model fit in an important way (R²=0,725).
breast; prediction; broilers; ultrasound
