Effect of concentrate levels on carcass characteristics of the Morada Nova breed sheep in feedlot

The in vivo carcass characteristics and the cut yields measured in the carcass of Morada Nova sheep finished in feedlot system fed increasing levels of dietary concentrate were evaluated. Thirty-two castrated Morada Nova lambs with 8.11 +/- 1.15 months of age and 19.67 +/- 2.97 kg of initial body weight were used in this trial. The experimet was analyzed as a completely randomized block design with eight replicates per treatment. Animals were slaughtered at 30.0 kg BW and fed diets with four concentrate levels: 20, 40, 60 or 80%. Linear increasing effect of dietary concentrate on empty body weight and cold carcass weight and yield and linear decreasing effect on digestive tract content and feedlot period were observed. The neck weight and yield linearly increased and the percentage of shoulder and leg linearly decreased with the concentrate levels, while the rib weight showed quadratic effect. In the in vivo measurements, only leg perimeter presented significant effect. There was a linear increasing effect for thoracic width and carcass compactness, while the hind width showed quadratic effect. The use of concentrate in the diet increased the weight and yields of cold carcass; however this maximization did not increase the weights and yields of commercial cuts from Morada Nova lambs.