Selenium-enriched Saccharomyces cerevisiae improves growth, antioxidant status and selenoprotein gene expression in...

One hundred and fifty 7-day-old Arbor Acres broilers were randomly assigned into five groups: group 1 served as a control that was fed a basal diet without selenium (Se) supplementation; groups 2, 3 and 4 were fed the basal diet supplemented with 0.15, 0.5 and 1.5 mg Se as Se-enriched Saccharomyces cerevisiae (SSC) per kg of diet; and group 5 was fed the basal diet supplemented with 0.15 mg per kg of Se as sodium selenite (SS). Growth performance, glutathione peroxidase (GP_X ) and superoxide dismutase (SOD) activities, total antioxidant capacity (T-AOC), and malondialdehyde (MDA) content in plasma and liver, and cellular glutathione peroxidase (GP_X -1) and phospholipid hydroperoxide glutathione peroxidase (GP_X -4) mRNA levels in liver were determined. Compared with group 1, groups 2-4 exhibited higher body weights (p < 0.05), lower feed/gain ratios, and higher GP_X activities in plasma (p < 0.05) and GP_X and SOD activities and GP_X -1 and GP_X -4 mRNA levels in liver (p < 0.05). Compared with group 5, group 2 exhibited higher GP_X activity in plasma on day 21 (p < 0.05). Compared with group 2 and 5, group 3 exhibited lower MDA content in plasma on day 7 (p < 0.05), higher GP_X activity in plasma, SOD activity and GP_X -1 mRNA levels in liver on day 14 and 21 (p < 0.05), and higher GP_X -4 mRNA levels on day 14 (p < 0.05). Compared with group 4, group 3 exhibited lower MDA contents in plasma on day 14 (p < 0.05) and in liver on day 21 (p < 0.05), higher T-AOC in plasma and higher GP_X -1 mRNA levels on day 14 and 21 (p < 0.05), and higher SOD activity in plasma and higher SOD and GP_X activities in liver on day 21 (p < 0.05). Thus, SSC improves growth and antioxidant status of broilers; the short-term bioavailability of SS was faster than that of SSC, but the long-term bioavailability of SSC was greater than SS.