ABSTRACT
The objective of this study was to evaluate the effect of increasing levels of substitution of sorghum silage by wet brewery residue as forage food on carcass characteristics and non-carcass components of lambs finished in feedlot. Twenty four non castrated male lambs, Suffolk breed, single birth were maintained in individual stalls. The treatments consisted of four substitution levels of sorghum silage by wet brewery residue (0%; 33.5%; 66.5% or 100% of substitution). Roughage and concentrate were used at a 50:50 ratio, based on dry matter. The concentrate was composed of ground corn, soybean meal and mineral mixture. The diets were isoproteic containing 18.81% crude protein. The lambs were slaughtered when they reached the body condition score of 3 (ranging from 1 to 5). The carcass traits were not affected significantly (P>0,05) by substitution of sorghum silage by wet brewery residue. The average values of hot carcass weight, cold carcass weight, hot carcass yield, cold carcass yield and cooling weight losses were 18.92 kg, 18.22 kg, 47.03%, 45.29%, 3.41%, respectively. The proportion of commercial cuts in relation to the cold carcass weight, was 31.86% for leg, 18.12% for shoulder, 39.46% for ribs and 9.08% for neck. The proportion of diaphragm, omasum full and empty omasum in relation to body weight at slaughter decreased linearly (P≤0.05). The remaining variables of non-carcass components were not affected (P>0.05) by wet brewery residue inclusion. We recommend the use of wet brewery residue as exclusive source of roughage food when using roughage:concentrate at 50:50 ratio on a dry matter basis, for finishing feedlot lambs.
Keywords:
meat lamb; yield; agroindustrial residues; roughage