Effects of dietary organic selenium supplementation on selenium content, antioxidative status of muscles and meat quality of pigs

The effects of feeding a high level of organic selenium on the level of selenium, antioxidative status of m. longissimus lumborum et thoracis (MLLT) and m. semimembranosus (MSM) and meat quality of pigs (defined on malignant hyperthermia status, DNA based test) were investigated. Treatments consisted in supplementation of organic selenium (0.3 mg Se/kg diet) for the last 97 days to finishing pigs (basic diet with 0.18 mg Se/kg diet) before slaughter. MLLT was further examined for pH (45 min, 24 h), colour and conductivity (24 h), drip loss (48 h) and myofibrillar fragmentation index (MFI, 5 days). Chemical composition (protein, intramuscular fat) was also estimated. Concentration of Se (spectrofluorometric method) and antioxidative status (rate of oxidation by stimulation with Fe2+/ascorbate, production of malondialdehyde - MDA) were estimated in muscle samples obtained post mortem. The level of selenium was more than twice higher (P < 0.05) in muscles from pigs treated with higher selenium than in controls (0.377 vs. 0.922 mg/kg - MLLT and 0.377 vs. 0.836 mg/kg - MSM). The rate of oxidation was positively (P < 0.05) influenced by Se supplementation. Tendencies to lower drip losses were observed in MLLT of pigs supplemented with Se but the differences were not significant (P > 0.05). We concluded that dietary organic Se supplementation (0.3 mg Se/kg diet) to basic diet (0.18 mg Se/kg diet) of finishing pigs significantly increased the selenium concentration and improved the antioxidative status of muscle tissue.