This study was undertaken to evaluate the influence of four substitution levels (0; 33; 67 and 100%) of Tifton 85 hay (TH) by castor bean hulls (CH) on carcass characteristics and non carcass components in Morada Nova crossbred lambs, with 20.3 kg body weight and 6.5 months old. A completely randomized design with four treatments and five replicates (lambs) was used. It was evaluated the carcass weight, the carcass yield, the relative composition of the commercial cuts and the non carcass components. There were negative linear effect of the substitution levels of TH by CH on final body weight, live weight with fasting, empty body weight, hot carcass weight and cold carcass weight, as well as hot carcass yield and cold carcass yield. The substitution levels of TH by CH presented negative influence on the commercial cuts when was added castor bean hulls on lambs diets, while there is not effect of the substitution levels of TH by CH on loin eye area and fat thickness. There is negative linear effect of the substitution of TH by CH on back loin yield, while the others commercial cuts were not influenced. There were effects of the substitution of TH by CH to the majority non carcass components, with exception to the gall bladder, bladder, nodule, abomasum, small intestine and fat from the heart. The castor bean hulls over 33% in substitution to the Tifton 85 hay in diets to the sheep influence negatively the carcass characteristics and the non carcass components.
biodiesel byproducts; lambs; relative composition of the commercial cuts; Ricinus communis