Effects of increasing dietary organic selenium levels on meat fatty acid composition and oxidative stability in growing rabbits

Abstract

The effects of dietary organic selenium (Se) addition at 0.1, 0.5 and 2.5mg/kg vs. an unsupplemented basal diet (BD) on performance, fatty acid (FA) composition and oxidative stability were studied in muscle tissue of growing rabbits. Muscle Se content increased (P<0.001) in a dose dependent manner with dietary Se inclusion. Saturated FA (SFA) were affected linearly (P<0.05) and quadratically (P<0.05) by dietary Se addition. Polyunsaturated FA (PUFA) increased linearly (P<0.01) resulting in a linear increase in the PUFA:SFA ratio (P<0.01) with dietary Se increment. Feeding 0.5mgSe/kg diet reduced malondialdehyde (MDA) and oxygen radical absorbance capacity (ORAC) values in the muscle, whilst 2.5mgSe/kg diet increased MDA concentrations and tended to increase ORAC values, likely indicating oxidative stress. In conclusion, dietary Se supplementation at 0.5mg/kg improves meat FA composition and oxidative stability, whereas at 2.5mg/kg may induce pro-oxidant effects.

Keywords: Fatty acids; Muscle; Oxidative stability; Oxygen radical absorbance capacity; Rabbits; Selenium yeast.