Breed differences and genetic parameters for body composition traits in beef cattle

Abstract

The recent scientific literature was reviewed to summarize breed differences and genetic parameters for carcass traits in beef cattle. Heritability estimates were generally moderate to large, suggesting good potential for accurate genetic selection for a given individual carcass characteristic. However, effectiveness of multiple-trait selection for some trait combinations could be slowed by genetic antagonisms between traits, suggesting the use of terminal breeding systems with complementary sire and dam genetic types. Individual and maternal heterosis estimates from age-constant analyses were numerically positive for most carcass traits, although estimates from weight-constant analyses were generally nonsignificant. Potential contributions to improved carcass composition from crossbreeding would primarily result from genetic complementarity rather than heterosis. Considerable variation exists between breeds for body composition, and breed rankings vary across different traits. Studies have consistently indicated reduced meat tenderness for Bos indicus compared with Bos taurus breeds. Some differences in breed rankings for marbling vs tenderness were noted. If the U.S. beef industry shifts toward a more value-based marketing system, some genetic concerns will include 1) an apparent antagonistic relationship between marbling and cutability across breeds and within some breeds, 2) inconsistency of beef tenderness, particularly in Bos indicus cattle, 3) the effect of increased leanness on female reproductive performance, and 4) the extent to which terminal breeding systems can be used.

Consistency statistics and genetic parameters for taste panel assessed meat quality traits and their relationship with carcass quality traits in a commercial population of Angus-sired beef cattle

“…A positive, although non-significant, correlation was also found between fat level and the taste panel-assessed tenderness trait. This suggests an increase in tenderness with an increase in fatness, which is consistent with published correlation coefficients between shear force and various fatrelated traits (Marshall, 1994;Blanchard et al, 2000;Riley et al, 2003).…”

“…Thus, a simple physical measurement of shear force cannot incorporate all the features of a humanbased evaluation (Warriss, 2000). The correlation is also lower than that from experiments involving the Warner Bratzler (WB) measure of shear force, a similar mechanical measure of tenderness (for review see Marshall (1994)) where published correlation coefficients between taste panel and WB shear force tended to be somewhat stronger (approximately 20.70) than in the present study. This discrepancy may be due, in part, to the small sample size or may be a reflection of the untrained taste panel used here.…”

Genetic parameters for carcass weight, conformation and fat in five beef cattle breeds

“…Charolais and Limousin had the highest carcass conformation and the lowest carcass fat levels, whereas Hereford and Angus had the lowest conformation levels and the highest fat levels. These breed differences are as previously reported (Marshall, 1994).…”

“…In Angus and Hereford, the two British small bodysized breeds with the highest fat and the lowest conformation levels (Marshall, 1994), carcass weight was genetically related to increasing fat, but conformation and fat were not related to each other. On the other hand, in Charolais and Limousin, the two continental large body-sized and muscular breeds with the lowest fat levels (Marshall, 1994), carcass weight and fat were weakly related to each other, but more conformed carcasses were genetically related to decreasing fat. Similarly, in the literature the strongest negative genetic correlations between conformation and fat occur in Charolais and Pirenaica Eriksson et al, 2003; Figure 2).…”

Proteome differences associated with fat accumulation in bovine subcutaneous adipose tissues

“…The crossbred HEAN have the genetic components of Hereford and Angus, while the CHAR animals have the genetic components of Charolais. Thus, it is not surprising that different proteins were detected for the two animal groups because Hereford and Angus breeds mature and fatten earlier than Charolais [37]. Therefore, the differences in protein expression might point to particular proteins that control fat formation in these two groups of animals.…”