Relative distribution of protein and non‐protein bound Se in liver and muscle of growing pigs fed two sources of dietary Se

Abstract

Our objective was to determine effects of dietary Se source and concentration on tissue distributions of protein bound Se (PBSe) or non‐protein bound Se (NPBSe) in pigs. Two trials were conducted with 36 weanling pigs fed a corn (from Se‐deficient area in Sichuan)‐soy basal diet (0.04 mg Se/kg) added with 0, 0.3, or 3.0 mg Se/kg as Se‐enriched yeast (SeY) or sodium selenite for 8 wk. At the end, all pigs were killed to collect liver and muscle for Se analysis using hydride‐generation atomic fluorometric spectrophotometer (AFS‐830, Titan Instr, China). The 2 forms of Se were separated by centrifugation after the tissue homogenates were treated with 10% TCA. Total Se concentrations in the two tissues of pigs fed either source of Se showed dose‐dependent increases (P < 0.05) with dietary Se levels. Relative percentages of the NPBSe and the PBSe to total tissue Se in liver were increased (P < 0.05) and decreased (P < 0.05), respectively, by the increases of dietary Se levels. This was also true for the relative distribution of the two forms of Se in muscle of pigs fed selenite. In contrast, the NPBSe and the PBSe remained constant at 6 and 94% of total tissue Se, respectively, in muscle of pigs fed the three levels of SeY. In conclusion, the relative distributions of the protein and non‐protein bound Se in liver and muscle were affected differently by dietary Se source (Chinese Natural Science Foundation Projects 30628019 & 30700585).