Two experiments were conduct to evaluate theeffect of dietary nutritive value and performance of sheep fed corn- or sunflowersilage-based diet with increasing concentrate proportion (20, 40 and 60%). Afactorial design (2x3) was used to evaluate nutritive value and digestibilitycoefficient of two silages with three concentrate levels and three sheep foreach treatment. For lamb performance, a randomized block design in a factorialarrangement (2x3) was used to evaluate lamb performance, with five Suffolk lambs/treatment.Apparent digestibility coefficients of DM, OM, CF, NFE, NDF, ADF and cellulosewere smaller for sunflower than for corn silage. Corn silage-based diets showedhigher values of daily dry matter intake (709.5 x 609.7 g), daily live weightgains (181.8 x 108.2 g) and lower values of feed:gain ratio (3.82 x 5.53 kgDM/kg LW gain) than sunflower silage-based diets. Sunflower silage-based dietsshowed lower nutritive values than corn silage-based and smaller lamb performance.Lambs fed sunflower silage-based diets need more concentrate ration to obtainperformance similar to those fed corn silage-based diets.
