Two experiments were conduct to evaluate the effect of dietary nutritive value and performance of sheep fed corn- or sunflower silage-based diet with increasing concentrate proportion (20, 40 and 60%). A factorial design (2x3) was used to evaluate nutritive value and digestibility coefficient of two silages with three concentrate levels and three sheep for each treatment. For lamb performance, a randomized block design in a factorial arrangement (2x3) was used to evaluate lamb performance, with five Suffolk lambs/treatment. Apparent digestibility coefficients of DM, OM, CF, NFE, NDF, ADF and cellulose were smaller for sunflower than for corn silage. Corn silage-based diets showed higher values of daily dry matter intake (709.5 x 609.7 g), daily live weight gains (181.8 x 108.2 g) and lower values of feed:gain ratio (3.82 x 5.53 kg DM/kg LW gain) than sunflower silage-based diets. Sunflower silage-based diets showed lower nutritive values than corn silage-based and smaller lamb performance. Lambs fed sunflower silage-based diets need more concentrate ration to obtain performance similar to those fed corn silage-based diets.
corn; digestibility; feed:gain ratio; intake; silage; sunflower
