Dietary Alteration of Palatability and Fatty Acids in Meat from Light and Heavy Weight Ram Lambs

Forty-four wholesale ribs from ram lambs fed one of five corn:roughage diets and slaughtered at 41 or 68 kg live weight were evaluated for differences in fatty acid composition and palatability. Total unsaturated fatty acids in subcutaneous fat were higher for lambs on diets that contained 72.57 or 79.50% corn than on diets that contained 0, 36.29 or 37.88% corn. Total polyunsaturated fatty acids followed the same trends; higher amounts were present in diets that were high in corn. Differences (P<.05) in flavor scores of ram lamb meat by diet were not related to changes in unsaturated fatty acid composition. In addition, the effect of diet on aroma, juiciness, tenderness and Warner-Bratzler shear values was not significant. Total unsaturated fatty acids were higher in fat from 68-kg lambs than from 41-kg lambs, but total polyunsaturated fatty acids decreased as weight increased. Panel scores for flavor were less desirable in rib roasts from older 68-kg rams than from younger 41-kg ram lambs, but panel scores for aroma of heated fat, juiciness and tenderness were not related (P<.05) to weight. Warner-Bratzler shear values were lower for meat from the 68-kg ram lambs than for meat from the 41-kg ram lambs. The data demonstrate that diet can influence fatty acid composition in ram lambs and that diet should be an important consideration in production of ram lambs for meat. However, the influence of diet and fatty acid composition on flavor and aroma of meat from ram lambs needs further study.