Performance, carcass traits, meat quality and composition of non-castrated Nellore and crossbred male cattle fed soybean oil

The effects of soybean oil inclusion in a high concentrate diet on performance, carcass traits, meat quality and fatty acid (FA) composition of 30 Nellore (NEL) and 30 non-castrated crossbred Angus x Nellore (AxN) animals were evaluated in an 133-d feeding study. Animals were assigned in a randomized complete block (initial body weight) design using a 2 x 2 factorial arrangement. Treatments consisted of two genetic groups (NEL and AxN) and two diets: 1) a basal diet containing no soybean oil (CON) and 2) a basal diet containing 3.5% of soybean oil (SBO). Performance data were obtained during the feeding period. After slaughter, carcass traits were recorded and longissimus muscle samples were collected for FA composition and meat quality. No diet x genetic group interaction was detected for any trait. Diet did not affect meat colour or tenderness; however, C14:0, conjugated linolenic acid and the n-6:n-3 polyunsaturated FA (PUFA) ratio increased (P < 0.05) with dietary SBO, whereas C14:1 c9, C18:1 c9, C20:3 n6, C20:5 n3, C22:5 n3, and n-3 PUFAs decreased (P < 0.05) in SBO. Lean from AxN had lower L* and b* values than NEL, whereas minimal changes were observed for the FA composition across genetic groups. Therefore, feeding SBO for lean purebred NEL or AxN crossbreed improves feedlot performance while carcass and meat quality trais are minimally affected.