Cattle blood plasma and red blood cell alpha-tocopherol levels in response to different chemical forms and routes of administration of vitamin E.
The chemical form and site of administration of vitamin E were assessed in cattle by measuring area under the time curve alpha-tocopherol levels in plasma and red blood cells (RBC). In Exp. 1, four groups of Holstein calves, 4 to 6 d old, received daily one of the following forms equivalent to 228 mg of alpha-tocopherol: D-alpha-tocopheryl acetate (DTA); DL-alpha-tocopheryl acetate (DLTA); D-alpha-tocopheryl polyethylene glycol 1,000 succinate (TPGS); and an experimental blend (EB) containing DTA and TPGS. A control group received no supplement. Temporal alpha-tocopherol responses were determined in blood samples collected for 35 d. Relative to controls whose plasma and RBC alpha-tocopherol levels remained unchanged, all supplementation increased (P less than .05) alpha-tocopherol levels in plasma and RBC in calves; the highest levels occurred in those that received either DTA or EB. In a second experiment, five Hereford steers with ruminal and duodenal cannulas were used in a crossover design to determine whether site of vitamin E administration affected plasma alpha-tocopherol levels. A single dose of 810 mg of DTA was placed daily into the rumen, and the same amount divided into five equal doses was given (into the duodenum) during a 12-h period. Plasma alpha-tocopherol levels were higher (P less than .05) when steers were ruminally dosed than when they were dosed duodenally. The results suggest that the alpha-tocopherol concentration of plasma and red blood cells in cattle depends on both the chemical form and on the site of administration.
Roquet
J
J
Department of Animal Sciences, Colorado State University, Fort Collins 80523.
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D000284:Administration, Oral; D000818:Animals; D002417:Cattle / Q000097:blood*; D004386:Duodenum; D004912:Erythrocytes / Q000737:chemistry*; D008297:Male; D012417:Rumen; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry
D014810:Vitamin E