RESUMO
Fifty-four castrated male lambs with an average body weight of 23 ± 0.35 kg were randomly assigned to five treatments that consisted of different levels of palm kernel cake in the diet (0.0, 7.5, 15.0, 22.5, and 30.0 % on a DM basis) in order to evaluate the effects on intake, digestibility, empty body weight, and body gain composition. The intakes of dry matter, organic matter, crude protein, and non-fiber carbohydrates (NFC) presented with a decreasing linear effect. However, the intakes of EE and NDF presented with increased linear results as the palm kernel cake was added to the concentrate. There was a quadratic effect for the digestibility coefficient of all nutrients, except for NFC. The palm kernel cake had a decreasing linear effect on final body weight, empty body weight, and the average daily gain of the animals that were fed increased levels of palm kernel cake. The inclusion of palm kernel cake as a partial substitute for concentrate decreases the intake of the majority of nutrients, except for EE and NDF, and consequently, causes deleterious effects on the nutrient digestibility and performance of lambs that are fed a 50:50 roughage/concentrate ratio.