The objective of this study was to evaluate the quantitative carcass traits of lambs from different genotypes receiving different levels of energy in the diet. Fifty-four non-castrated lambs - 18 Santa Inês (SI), 18 F1Dorper × Santa Inês (Dp × SI) and 18 F1Santa Inês × No defined breed (SI × NDB) - of average 150 days old and 22.6-kg BW were used in the beginning of the experiment. Diets contained 17% crude protein and 2.40 Mcal/kg DM or 2.90 Mcal/kg DM. Lambs fed the diet containing 2.90 Mcal/kg DM showed higher final live and carcass weight, loin eye area, percentage of internal fat, muscularity index, compactness of the carcass index, percentage of fat and lower muscle:fat relation. These lambs' carcasses also presented lower percentage of cold loss and higher weight and percentage of shoulder and leg. Carcasses of Dp × SI lambs were superior in fat thickness, GR site, percentage of fat, muscle:bone relation, muscularity index, weight and percentage of loin. Santa Inês sheep showed higher muscle:fat relation. Both diet and genotype influence quantitative carcass traits of lambs.
Dorper; loin eye area; sheep; Santa Inês; tissue composition
