Heritability estimates for carcass traits of cattle: a review.

We present estimates of heritability for carcass traits of cattle published in the scientific literature. Seventy-two papers published from 1962 to 2004, which reported estimates of heritability for carcass traits, were reviewed. The unweighted means of estimates of heritability for 14 carcass traits by slaughter end point (age, weight, and fat depth) were calculated. Among the three end points, carcass weight, backfat thickness, longissimus muscle area, and marbling score were the carcass traits with the most estimates of heritability (56 <or= n<or=66). The averages for these traits indicate that they are similarly and moderately heritable (0.40, 0.36, 0.40, and 0.37, respectively). However, heritability estimates for most traits varied greatly, which could be due to differences in breed groups, methods of estimation, effects in the model, number of records, measurement errors, sex, and management. Few studies have compared heritability estimates for carcass traits adjusted to different end points. Results from such studies have been inconsistent, although some studies revealed that heritability estimates for several carcass traits are sensitive to the covariate included in the model for the end point, implying that direct response to selection would be different for some traits depending on slaughter end point. The effect of different end points on estimates of heritability for many carcass traits has not been studied.