Acacia mearnsii tannin extract and α-tocopherol supplementation in lamb diet: Effects on growth performance, serum lipid peroxidation and meat quality

This study investigated the effects of supplementing lamb diets with plant bioactive compounds α-tocopherol, tannin and the association of both on lamb growth, blood and meat characteristics. Forty male lambs were housed in individual pens and assigned to four treatment groups (10 animals/group), where, for 62 d, they were fed: 1) a basal diet with soybean hulls, soybean meal and corn (Control); 2) the Control diet containing α-tocopherol (Tocopherol); 3) the Control diet containing Acacia mearnsii tannin extract (Tannin); and 4) The Control diet containing A. mearnsii extract and α-tocopherol (Tannin + tocopherol). The Tannin and Tannin + tocopherol treatments resulted in lower cold carcass weight. The concentration of α-tocopherol in the muscle was higher in Tocopherol and Tannin + tocopherol treatments. Meat lipid oxidation, after 7 days of storage, was lower (P ≤ 0.05) in lambs fed Tocopherol and Tannin + tocopherol than in the Tannin treatment, while the treatments with Tannin experienced a trend of reduced serum lipid peroxidation. Tannin diets modified the meat fatty acid profile, with an increase in C17:0 and in the PUFA/MUFA ratio and a decrease in the enzymatic Δ9-desaturase activity (C16 and C18) and in the MUFA/SFA ratio, in addition to promoting a increasing in the sum of PUFAs. Lamb supplementation with α-tocopherol and A. mearnsii tannin are alternatives capable of improving meat quality and reducing serum lipid peroxidation. •Tannin and tocopherol in lamb diets did not affect meat pH, color and cholesterol.•Alpha-tocopherol in finishing lamb diet increased its content in the muscle.•Alpha-tocopherol in finishing lamb diet decreased the meat lipid oxidation.•Tannin in lamb diets improved meat ∑PUFA contents and reduced serum lipid oxidation.•There was no interaction between dietary tannin and tocopherol on lamb meat quality.