Vitamin E: pharmacokinetics of parenteral products and its effect on swine reproduction

Two experiments were conducted to evaluate the pharmacokinetics of parenteral products of d-[alpha]-tocopherol and its acetylated ester. Then, a third experiment was undertaken to assess the effect of dietary and i.m. (one of the alcohol sources previously evaluated) vitamin E supplementation on reproductive performance and tocopherol status of sows and their progeny. Alpha-tocopherol concentration with time data were fitted to a sum of exponentials. Compartmental models were developed based on the slopes and intercepts of the exponential equations. The absorption from the place of injection was calculated to be 43 and 40% of the dose after i.m. administration of d-[alpha]-tocopherol and d-[alpha]-tocopherol acetate, respectively. The ratio of the area under the curve for d-[alpha]-tocopherol/d-[alpha]-tocopherol acetate was between 1.26 to 1.33. Products as emulsion were readily available, whereas the product using olive oil as a carrier was not. Animals receiving the acetate sources had serum and tissue vitamin E concentrations only detectable as alcohol 14 d after administration. The injection of the alcohol source of vitamin E resulted in greater total muscle [alpha]-tocopherol content than the acetate source. These results indicate that: olive oil was not a good carrier for i.m. vitamin E preparations; when vitamin E was formulated with an adequate carrier, it was readily available and improved vitamin E status of the pigs; pigs were able to hydrolyze the acetate to alcohol vitamin E; and that i.v. administration of vitamin E resulted in adverse systemic reactions, whereas the i.m. route did not. Therefore, the i.m. route is the therapeutic tool of choice to rapidly increase plasma [alpha]-tocopherol concentration of deficient animals. Dietary and injectable tocopherol supplementation of the sows can improve the tocopherol status of sows and their offspring. Pigs were born depleted of vitamin E, but the immediate uptake of colostrum replete them. When reproductive performance was used as response criterion, 11 IU of vitamin E per kg of diet for gestating and 22 IU/kg for lactating sows may be adequate for sows fed diets containing.3 ppm of Se for three consecutive parities