Se Yeast Supplementation Research Articles

Effect of Se source and dose on selenomethionine and selenocysteine levels in blood and plasma of mature horses

The study comprised 25 mature horses and incorporated five dietary treatments; a nega tive control (C: 0.085 mg Se/kg DM), 3 levels of Se yeast supplementation, obtained from Saccharomyces cerevisiae CNCM I-3060 (OS2, OS3 and OS4: 0.2, 0.3 and 0.4 mg Se/kg DM respectively) and one positive control supplemented with Na selenite (IS3: 0.3 mg Se/kg DM). Diets were offered for 112 days. Total Se, proportion of total Se comprised as selenomethionine (SeMet) or selenocysteine (SeCys) of pooled samples of blood and plasma for each treatment at d 0.56 and 112 were determined. Total Se and SeCys increased both in blood and plasma during the trial in all treatments supplemented with Se; these increases were proportional to the level of dietary Se supplementation. The SeMet increased only in treatments supplemented with Se yeast, with increases proportional to the level of dietary Se supplementation. In Se yeast horses the proportion of total Se comprised as SeMet accounted for 20 and 14% of total Se increase in blood and plasma respectively; in IS3 only accounted for 5 and 3% respectively. These results seem support the view that SeMet is a non-specific form of Se that is metabolized as a constituent of the methionine pool, and can be considered as a storage form of Se in higher animals.

Effects of selenium source and level of supplementation on the performance and meat quality of lambs

Objective of this study was to evaluate the performance, the quality and oxidative stability of meat, the total Se and specific selenoamino-acids content of muscle of lambs that were fed diets supplemented from different Se sources and at different levels. Forty-eight Apennine lambs 30 day old (12.78 ± 0.94 kg) received, during a 63 day period, a total mixed ration (TMR) which was either Se unsupplemented (Control group - background only- 0.13 mg/kg Se) or supplemented with Na selenite (0.30 mg/kg Se as sodium selenite) or selenium enriched yeast (0.30 mg/kg and 0.45 mg/kg Se as Se-yeast). Growth performance, feed to gain ratio, carcass and meat quality (pH, drip and cooking losses, colour, GSH-Px activity and chemical analysis) did not show any difference between the treatments. Meat colour and oxidative stability during 9 days of refrigerated storage were unaffected by dietary supplementation, suggesting that, at the levels of Se used in this experiment, dietary Se, even from an organic source, had limited potential for reducing lipid oxidation. Selenium supplementation raised the Se content in muscle ( P < 0.001) with the greatest increase when Se-yeast was fed. Although selenite increased total Se, it did not influence total or specific selenoamino-acids in this tissue. On the contrary, Se-yeast supplementation led to an increase in muscle Se-methionine content. We conclude that Se supplementation can increase significantly muscle Se levels and produce, particularly when Se-yeast is fed, a source of Se enriched meat as Se-methionine.

Selenium Supplementation of Children in a Selenium-Deficient Area in China : Blood Selenium Levels and Glutathione Peroxidase Activities

Keshan disease is a cardiomyopathy restricted to the endemic areas of China and seen in residents having an extremely low selenium (Se) status. Prophylactic administration of sodium selenite has been shown to decrease significantly the incidence of acute and subacute cases. The aim offthe study was to assess the relative bioavailability of selenite versus organic Se-yeast in a Se-deficient area in China with a randomized double-blind double-dummy design. Healthy children (n=30) between 14 and 16 yr of age were randomized into three equal groups receiving either 200 microg/d selenite Se or 200 microg/d Se-yeast or placebo for 12 wk. Blood was drawn at baseline, 4, 8, and 12 wk and 4 wk postsupplementation. The plasma Se concentration (mean +/- SD) was 0.16+/-0.03 micromol/L at baseline. Selenite and Se-yeast supplementation increased plasma Se to plateau values, 1.0+/-0.2 and 1.3+/-0.2 micromol/L, respectively. In red cells, Se-yeast increased the selenium level sixfold and selenite threefold compared to placebo. The relative bioavailability of Se-yeast versus selenite measured as glutathione peroxidase (GSHPx) activity was similar in plasma, red blood cells, and platelets. GSHPx activity reached maximal levels in plasma and platelets of 300% and 200%, respectively, after 8 wk compared to the placebo group, but continued to increase in red cells for 16 wk. Our study showed that although both forms of Se were equally effective in raising GSHPx activity, Se-yeast provided a longer lasting body pool of Se. Se-yeast may be a better alternative to selenite in the prophylaxis of Keshan disease with respect to building up of body stores.