Macadamia oil and vitamin E for lambs: performance, blood parameters, meat quality, fatty acid profile and gene expression

This study evaluated the effect of dietary supplementation of macadamia oil and vitamin E on lamb's growth, blood parameters, carcass, meat quality and the expression of genes related to lipid metabolism of the Longissimus lumborum muscle. Thirty male lambs Santa Ines x Dorper (22.6 +/- 2.59 kg) were divided into three diets: control (n = 10); macadamia oil (supplementation of 0.1% live weight) (MO) (n = 10) and MO with vitamin E (500 mg/kg DM) (MOVE) (n = 10). Plasma cholesterol increased in lambs fed with MO whereas plasma insulin increased in lambs supplemented MOVE (P = 0.011). Lambs fed with MO reduced dry matter intake (P = 0.002) and improved feed efficiency (P = 0.001) without impairing daily weight gain and carcass charac-teristics (P > 0.05). The use of MO increased the intramuscular fat and consequently improved meat's flavor (P = 0.043) and tenderness (P = 0.027). The inclusion of vitamin E positively re-duces lipid oxidation (P = 0.002). Inclusion of MO in the diet increased C18:3 n3 (P < 0.001) in meat and the expression of the stearoyl-CoA desaturase (SCD1) (P = 0.022) and elongase 6 (ELOVL6) (P = 0.019) genes when associated with vitamin E.