Growth and carcass traits of bulls and veal calves of continental cattle breeds 2. Carcass composition

Sibs of five to 11 twin pairs each of five breeds were either slaughtered as veal or as yearling bulls. Highly significant breed differences were evident in the carcass tissue proportions which could be explained on the basis of differences in the physiology of dairy and dual-purpose animals, the former depositing more fat and more bone than dual-purpose breeds. Among the dual-purpose breeds the carcasses of the Pinzgauer (Pi) tended to rank between the carcasses of the Fleckvieh (FV), Braunvieh (BV), Grauvieh (GV) and those of the Friesian (Fr). The dual-purpose breeds FV, BV, GV had more meat in the hindquarter and in the shoulder than the FR while these in turn had more meat in the brisket and in the flank and shank muscles. Again the Pi group tended to rank between the aforementioned groups. Within breeds, large differences between twin pairs indicated high heritabilities for carcass tissue proportions and ratios. The heritability of commercial cut proportions was fairly high but the genetic variance was small, the genetic coefficient of variation being less than 0-02. The different degrees of sexual maturity and of carcass maturity also caused differences in the distribution of meat in the carcasses of young male animals. Significant mean squares for interactions between treatments and breeds, and genetic correlations of less than unity between performance of twin genotypes in veal and in bulls, indicated age and/or rearing system by genotype interactions between and within breeds for various slaughter traits. Phenotypic correlations between various slaughter traits were low except where part-whole relationships were involved. It is suggested that slaughter at comparable maturity in the respective treatments was the cause of the weak connection between the traits.