Eighteen male lambs (initial weight 30±1.3 kg and 5-6 months) were used in this experiment
to study the effect of energy levels on the performance, nutrient digestibility and carcass
traits. Total experimental period was 90 days. The animals were allotted into 3 groups, 6
animals per each. The first group was fed a medium energy (ME) diet (3.20 Mcal/kg diet),
while the second group fed on diet contained high energy (HE) level ( 3.50 Mcal/kg diet) and
the third group fed on low energy (LE) diet ( 2.90 Mcal/kg diet). All diets contained 14.70%
crude protein in dry matter. The average daily feed intake was affected significantly (P<0.05)
by the level of energy and lambs group fed on low energy ration had significantly (P<0.05)
increased feed intake compared with other treatment groups. Lambs that received the highest
energy level diet had a higher significant (P<0.05) average daily gain than that received the
medium and low energy diets. Feed conversion was deteriorated in lambs group fed on low
energy diet. The digestion coefficient of nutrients and total digestible nutrient were increased
significantly (P<0.05) with high energy diet. Dressing percentage and body fat was increased
with feeding high dietary energy. It could be concluded that the high dietary energy produced
the best performance, nutrient digestibilities and carcass traits of lambs.