The experiment was carried out at Sheep Production Department,Universidade de Marília-SP, to evaluate the effect of energy levels (2.6,2.8 and 3.0 Mcal ME/kg DM) on objective measures of carcasses and loin, cutsweight and yield and tissue composition and muscularity of carcasses of lambsunder creep feeding. Isoprotein rations (18.50 %CP) were fed ad libitum,twice a day. Lambs stayed with their dams until slaughter weight ( 31 kg). After,lambs were fasted, when slaughter live weight was recoded. During cooling at5ºC by 24 h, carcasses were hanged by tarse-metartase articulation,distanced by 17 cm, and, then, were measured. Later, carcasses were sectionedand the left side was divided in seven anatomical parts (shoulder, leg, loin,true ribs, false ribs, breast point and neck) to calculate weight and yieldof cuts. Then, muscle Longissimus dorsi was evaluated. Left leg was dissectedand it was considered muscle, fat and bone weights. Muscularity index was figuredout. Results showed significant differences for thorax depth, true ribs weightand yield, and leg intermuscular fat. It was concluded that ration with 3.0Mcal ME favored better results for Suffolk lambs fed and finished in creep feeding.
