Dressing percentage and its relationship with some components of the fifth quarter in Portuguese cattle breeds

Dressing percentage, inter-breed variations and its relationship to carcass fat and several components of the fifth quarter (visceral fat, alimentary tract, visceral organs, hide, feet and head) were studied. A total of 165 animals from the large (Alentejana, Mirandesa and Marinhoa) and small (Arouquesa, Barrosã, Maronesa and Mertolenga) breeds, submitted to the same feeding regime and serially slaughtered according to the respective size group, were involved. In relation to dressing percentage, our results indicated that, as the empty body weight increased, carcass fat and visceral fat were not directly accounted for by the 5% increase in dressing percentage from the first to the last slaughter point. The alimentary tract and hide, which exhibited a decreasing proportion as empty body weight increased, accounted for most of the variation in dressing: alimentary tract, alone, accounted for 0.61 and hide accounted for an additional 0.13. As regards dressing differences between breeds, at the same carcass subcutaneous fat level (42 g/kg carcass weight), our findings show that the two large breeds (Marinhoa and Mirandesa) had the highest values (about 3.5% more), which were significantly different from small breeds. However, Alentejana, also a large breed, showed a value for dressing close to the small breeds. The lowest proportion of visceral organs and hide in large breeds accounted for most of the differences between large and small breeds. Carcass fat, visceral fat, alimentary tract, feet and head tended towards homogeneity. In relation to carcass fat only, Mertolenga, with 31 g/kg empty body weight, was significantly different from Mirandesa and Marinhoa. Regarding visceral fat, only the Marinhoa breed, with 10 g/kg empty carcass weight lower, was significantly different from Barrosã. The figures for alimentary tract, excepted for Marinhoa, were not significant different between breeds.