Selenium (Se) is essential for normal muscle function in animals. Dietary Se deficiency in animal can cause various types of muscular dystrophy related to oxidative stress. The oxidative stress induced by Se deficiency and excess selenite metabolism can reduce the water-holding capacity of meat. Among the 24 selenoproteins identified in mammals, most have been reported to be involved in redox regulation. However, it is not known whether Sepw1 and some other selenoprotein genes are highly expressed in pig muscle and whether the expression of these genes have relation with the antioxidant status and meat quality, so we conducted the present study to explore the issue. To study the effect of selenium-enriched yeast (SeY) level on selenoprotein genes expression and the relation between gene expression and antioxidant status and meat quality, 30 selenium (Se)-depleted pigs (7-week old, 10.30±0.68 kg) were randomly divided into 3 groups and fed a basal diet plus 0, 0.3 and 3.0 mg Se/kg as SeY for 8 weeks.
Results showed that dietary SeY supplementation improved the antioxidant status in muscle. The increased levels of SeY decreased (P<0.05) the drip loss and the concentration of thiobarbituric acid reactive substances in the muscle and meat. However, increased dietary SeY intake quadratically increased (P<0.01) the mRNA level of Sepw1 gene among the 12 selenoprotein genes examined in muscle. Statistical analysis showed drip loss was negatively correlated with the mRNA level of Sepw1 gene.
In conclusion, the antioxidant status of pig tissue was regulated by the dietary Se level, and the inclusion of SeY in the pig diet increased the expression of the Sepw1 gene and improved meat quality. Although the addition of 3.0 mg Se/kg to pig diet is less likely in practice, this finding of our study suggested that the increased expression of the Sepw1 gene contributed to the improvement in the meat water-holding capacity.
JG Li, JC Zhou, H Zhao, XG Lei, XJ Xia, G Gao and KN Wang, 2011. Meat Science, 87:95-100.