The aim of this study was to evaluate the effect on intake, digestibility and fractionation of carbohydrates and proteins of cottonseed cake as an alternative protein source in rams diets. The diets were composed of corn silage, soybean meal, ground corn, urea, and cottonseed cake (0, 70, 140 and 210 g/kg dry matter (DM)) in a roughage/concentrate ratio of 50:50. Thirty-two Santa Ines rams, average age 12 months and weight 27.48 ± 4.96 kg were distributed in a completely randomised design. A reduction of 0.161 g/day in crude protein (CP) intake was observed for each gram of cottonseed cake inclusion. The intake of non-fiber carbohydrate (NFC) decreased by 0.511 g/day for each gram of cottonseed cake inclusion. Similarly, the ratio between intake of DM (p = 0.034), CP (p p = 0.004) and body weight decreased with cottonseed cake inclusion. Inclusion of cottonseed cake caused decreases in the digestibility coefficients of DM (p p p = 0.002). A reduction of 0.716 g was observed in carbohydrate fraction A + B1 (p = 0.006). The inclusion of cottonseed cake in the rams feed should be carried out with caution because this by-product promotes linear reduction in intake and digestibility nutrient, in addition to modifying the amounts of digestible and indigestible fractions in the diets.
