Carcass characteristics, chemical composition and fatty acid profile of Longissimus muscle of bulls and steers finished in a pasture system bulls and steers finished in pasture systems

Abstract

This experiment was carried out to study the carcass characteristics, chemical composition and fatty acid profile of the Longissimus muscle (LM) of bulls (10) and steers (17) finished in a pasture system. Animals (1/2 Zebu vs. 1/2 Aberdeen Angus) were fed in a pasture system (Hermatria altissima) and with a supplement of soybean meal, cracked corn, urea, limestone and mineral salts, twice a day. Both animal groups were slaughtered at 27 months of age, with an average 508.88 kg of live weight. Final weight, hot carcass weight and texture were similar (p>0.05) between bulls and steers. Carcass dressing, fat thickness, color and marbling were higher (p<0.02) in steers. Conversely, the Longissimus area was greater (p<0.05) in bulls. Moisture levels were higher (p<0.01) in bulls. Ash, crude protein, total lipids and total cholesterol levels were higher (p<0.10) in steers. C14:0, C16:0, C16:1 n-1 and C18:1 n-9 fatty acids percentages were higher (p<0.06) in steers. C16-1 n-10, i 17:0, C19:0, C18:2 n-6, C18:3 n-3, C20:2 n-3 C20:4 n-6, C20:5 n-3, C22:1 n-7, C22:4 n-6 and C22:5 n-3 fatty acids percentages were higher (p<0.05) in bulls. The percentage of the other fatty acids was similar (p>0.05) in bulls and steers. The levels of monounsaturated fatty acids were higher (p<0.02) in steers while polyunsaturated fatty acids, n-3, n-6, PUFA/SFA and n6:n3 ratios, were higher (p<0.05) in bulls. The CLA contents (mg/g lipids) were similar (p>0.10) in bulls and steers.