ABSTRACT:The objective was to evaluate the effect of different levels of selenium with two levels of grain corn in the diets on ruminal, postruminal, and total tract digestion of nutrients, ruminal fermentation characteristics, and selenium balance in lambs. A split-plot design was used in four periods with repeated Latin square using eight Suffolk × Dorset male lambs with four levels of selenium (sodium selenite, Na 2 SeO 3 ), without adding selenium, 0.3, 0.6, and 0.9 mg of selenium/kg dry matter (DM) with 70 and 50% of corn grain in the diet. The four selenium levels affected organic matter as follows: starch, neutral detergent fibre, nitrogen and selenium excretion; selenium ruminal digestion; organic matter, neutral detergent fibre, nitrogen and selenium postruminal digestion; and organic matter, neutral detergent fibre, nitrogen and selenium total tract digestion (P < 0.05). Starch and organic matter flow decreased with 0.6 and 0.9 mg of selenium with the 70% grain diet (P < 0.05). Selenium flow increased linearly with selenium levels (P < 0.01) with both levels of grain. Selenium supplementation increased linearly selenium concentration in ruminal fluid (P < 0.01), but did not affect other ruminal characteristics. Also, selenium absorption and retention was increased by selenium concentrations (P < 0.01). The apparent absorption of selenium increased (31%, P < 0.01) with the 70% grain diet. In conclusion, the high content of nonstructural carbohydrates improved the availability of selenium and 0.9 mg of selenium/kg DM improved the absorption and availability of selenium.

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Blood plasma and tissue Vitamin E concentrations were determined in 20 sheep following a single i.p. dose of 5 g of dl-alpha-tocopherol. In addition, five sheep were used as controls (no treatment and killed at d 0). From the 20 vitamin E-dosed sheep, 4 were slaughtered on d 3, 6, 10, 15 and 28 after dosing. There was a significant time effect in alpha-tocopherol concentrations in all tissues. In most tissues, the peak alpha-tocopherol concentration was at 3 d postdosing. Uptake varied among the different tissues examined. Three days postdosing, a large uptake of vitamin E by the liver was observed; this supports the concept that hepatic tissues are a target organ for vitamin E action. Also at 3 d uptake was pronounced in spleen and lung. Vitamin E concentrations in the other body tissues at d 3 postdosing increased considerably, but to a lesser degree than those in liver, spleen and lung. Vitamin E concentration in all tissues declined 3 d after i.p. dosing.

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Summary ― A 61-d study involving 40 crossbred lambs evaluated the effect of various forms of tocopherol provided daily in equimolar amounts on total cholesterol, high-density lipoproteincholesterol and triglyceride concentrations in the serum of lambs. Thirty-five lambs were allotted to 7 treatment groups of 5 animals each, supplemented with 300 mg tocopherol either as: 1) DL -atocopheryl acetate; 2) D -a-tocopheryl acetate; 3) D- 0.05) for any serum measured component. The present data strongly suggest that short-term treatment (< 2 mo) with pharmacological oral doses of various forms of vitamin E did not influence serum lipid metabolism of lambs. The data also showed that the bioavailability of cc-tocopherol is dependent on the form administered. D -a-tocopherol acetate is a highly available form, the bioavailability of which is further increased when combined with o-a-tocopheryl polyethylene glycol succinate.