Supplemental silicon increases plasma and milk silicon concentrations in horses

The primary objective of this research was to determine the effect of suppl emental dietary silicon (Si) on plasma and milk Si concentrations of lactat ing mares and the subsequent effect on plasma Si concentrations in nursing foals. Additionally, the role of Si on altering biochemical markers of bone turnover was investigated, because supplemental Si may be advantageous in enhancing bone health. Twelve Arabian mare/foal units were pair-matched by foaling date and randomly assigned to two groups, Si-supplemented (Suppleme nted) or control (Control). Blood and milk samples were taken on d 0, 15, 3 0, and 45, d 0 being the 1st d after parturition. Plasma and milk (or colos trum) Si concentrations were determined and serum was analyzed for osteocal cin, carboxy-terminal pyridinoline cross-linked telopeptide region of type I collagen, and pyridinoline and deoxypyridinoline crosslinks. All Suppleme nted mares had higher (P < 0.01) plasma Si concentrations than Control by d 30, and Supplemented mares' milk had higher (P < 0.01) Si concentrations o n d 45 than Control mares' milk. By d 45, foals of Supplemented mares had h igher (P < 0.01) plasma Si concentrations than foals of Control mares. Supp lemental Si did not influence (P > 0.36) bone metabolism in foals; however, trends (P < 0.10) for altered bone metabolism were observed in postpartum mares. Results indicate that supplemental Si increases plasma and milk Si c oncentrations. Further research is required to determine whether Si has a r ole in altering serum biochemical markers of bone and collagen activity.