This experimentaimed to determine the influence of diets with inclusion of protected fat andvitamin E on performance, yield and carcass characteristics of feedlot lambswith different weights. Thirty-two non-castrated Santa Ines lambs were fed dietswith a ratio of 40% forage and 60% concentrate ad libitum, with presenceor absence of protected fat and/or vitamin E, in a total of four diets. Twoweights of early containment were also considered: between 20 and 25 kg andbetween 30 and 35 kg. All animals were slaughtered at 84 days of confinement.Animals fed diets without addition of protected fat, regardless of the use ofvitamin E, had the highest intakes of dry matter, crude protein, neutral detergentfiber and ash, and decreased intake of ether extract. The variables investigateddid not affect daily weight gain and total gain. Feed conversion was betterfor the lighter confined animals not fed protected fat. The heavier feedlotlambs fed diets with vitamin E showed higher cold carcass. The warm carcassfor the lighter animals confined fed with vitamin E, and the heavier ones, fedwith protected fat and vitamin E, showed the best yields of cold carcass. Objectivemeasures of the carcass cold had the highest mean for heavier feedlot lambs.The addition of fat in the diet reduces the intake of dry matter and increasesthe ether extract. Although the inclusion of vitamin has no effect on intakeof nutrients, it protects the carcasses from losses during cooling, and weightdifferences at containment directly reflect the measures of the carcasses.
