RESUMO
One hundred forty-four steers were group-housed in 24 pens that were randomly assigned to one of four dietary treatments defined by the proportion of wet distiller grain plus solubles (WDGS; 0, 15, 30, or 45%) and fed for 84 d pre-slaughter. Animal performance was evaluated using the pen as the experimental unit. Whereas for carcass and meat quality characteristics, meat oxidative stability, and the consumer sensory quality of longissimus thoracis muscle one animal from each pen was randomly selected and used as the experimental unit. No differences (P > 0.05) were observed for subcutaneous fat thickness, rib eye area, marbling score or pH, color parameters, proximate composition, sarcomere length, Warner Bratzler shear force, and cooking loss. Feeding WDGS linearly increased total PUFA (P = 0.05), C18:2 n-6 (P = 0.004) proportions, and n-6/n-3 ratio (P < 0.01) but reduced C16:1 to C18:0 ratio (P < 0.01). Lipid oxidation was greater in beef from steers fed 30% and 45% WDGS (P = 0.05). Dietary WDGS linearly improved (P < 0.05) flavor and overall linking score in the consumer sensory panel.
Assuntos
Ração Animal , Zea mays , Bovinos , Animais , Ração Animal/análise , Carne/análise , Dieta/veterinária , Grão Comestível/química , Composição CorporalRESUMO
Angus steers were grazed on unsupplemented pasture (CNTRL), pasture supplemented with 0.7% BW cracked corn (FLAX-0), FLAX-0 with 0.125% and 0.250% BW of whole flaxseed (FLAX-1 and FLAX-2). Six steers were grazed per treatment for 70 days, with start and finish weights of 458 and 508 kg. At 24 h post slaughter, longissimus thoracis were harvested, and steaks assigned to treatments of postmortem aging time under vacuum (PM; 3, 14 and 56 days) with or without five days of aerobic exposure (AE). Meat antioxidant status was higher (P<0.05) when feeding CNTRL and FLAX-1 than FLAX-0 and FLAX-2. Under AE, lipid oxidation was highest for FLAX-2 (P<0.05), and lowest for FLAX-1. Greatest TBARs and lowest antioxidant capacity and redness values were obtained with AE and the longer PM (P<0.05). Beef oxidative stability through AE improved by adding a low flaxseed level to supplemented corn grain, but deteriorated by adding a high flaxseed level or by extending PM.