Comparative Effect of Organic and Inorganic Selenium (Selenium Yeast) Supplementation on Serum Selenium Concentration and Glutathione Peroxidase in Jumping Horses

Selenium is a component of some important selenoproteins and enzymes required for main functions in organisms as antioxidant defense, reduction of inflammation, thyroid hormone production, DNA synthesis, fertility, reproduction and killing cancer cells (by reducing the blood supply to tumors). This study was conducted to determine the effects of organic and inorganic selenium (Se) supplementation on serum Se status. 21 healthy mix breed horses 5-8 years of age were randomly divided into three groups, control without Se (CTRL), non-organic bolus (INORG) and organic Se (ORG) and in one of the horse riding clubs in Tehran province. Animals were located in control and treatment groups. Control group received only routine equine diet (were fed a typical alfalfa, grain and straw yields) for 28 days. First treatment group received routine diet plus premix (included 1 mg sodium selenite/day) and a second group was supplemented with 1 mg commercially available –enriched yeast (O-Sel). Blood samples (5ml) were taken by venoject tube from jugular vein on day 0, 14 and 28. Serum selenium levels were measured by atomic absorption method and serum glutathione peroxidase was measured using a biochemical kit. Serum activity of glutathione peroxidase showed a significant difference between the two treatment groups compared to control group (p≤ 0.05). Mean serum Se concentration on d 14 and 28 was greater (P<0.006) for Se-supplemented horses compared with CTRL horses, and tended (P<0.004) to be greater in ORG vs. INORG on d 28. The results of present study showed that use of selenium premix increased blood sera according to results and organic supplementation in horse appeared more efficient and the enzyme glutathione peroxidase could be a good indicator for assessing selenium status in the study groups.