The effect of metabolizable energy level (ME), due to increasing levels of forage nitrogen detergent fiber (fNGF), on the carcass tecidual composition of 64 Santa Inês lambs was evaluated. Four treatments (diets) were: diet A- fNDF; diet B- 17.3%; of fNDF; diet C- 26.0% of fNDF; and diet D- 34.7% of 8.7% fNDF in the diet. Four animals of each treatment were slaughtered at 43, 83, 123, and 173 days. Lambs fed diets A and B, showed higher weight of bonne tissue (BT), muscular tissue (MT), fatty tissue (FT), and other tissues (OT) in cold carcass at 83 days of age. The percentage of BT in cold carcass of the lambs fed diets A and B was lower, and percentage of FT was higher, after 83 days of age. The regression of each variable on ME total intake (Mcal), for each treatment, suggested higher intensity of deposition of FT for lambs fed diet A.
lamb; growth; energy level; carcass