title: Vitamin E supplementation and stress affect tissue alpha-tocopherol content of beef heifers.
abstract: The effect of stress on tissue alpha-tocopherol was investigated in 16 crossbred heifers fed a corn/corn silage-based diet. For 28 d, eight heifers (379 +/- 10 kg BW) received a dietary supplement of 1,000 IU of dl-alpha-tocopheryl acetate, whereas the controls (375 +/- 10 kg BW) received no supplemental vitamin E. Tissue samples of plasma, red blood cells, liver, trapezius, and longissimus muscles and subcutaneous fat immediately dorsal to each muscle were taken on d 1 for determination of alpha-tocopherol concentration. On d 2 through 4 each heifer was restricted to 2.61 kg of grass hay and allowed water. On d 5, 6, and 7 no feed or water was given, 100 IU of ACTH and .0024 mg of epinephrine/kg BW were given every 8 h, and biopsies for alpha-tocopherol content were again taken on d 7. The stress reduced (P < .01) mean BW, increased (P < .01) serum cortisol, creatine kinase, and urea. After stress, supplemental vitamin E reduced (P < .13) the increase in creatine kinase relative to that in heifers not supplemented with vitamin E. Stress also increased (P < .04) serum Se in heifers fortified with the vitamin E. Alpha-tocopherol content of plasma, red blood cells, liver, and subcutaneous fat dorsal to the trapezius muscle was increased (P < .01) by supplemental vitamin E. The stress treatment reduced (P < .01) alpha-tocopherol content of plasma in those fed the vitamin E and increased it (P < .05) in the nonsupplemented vitamin E-deficient heifers. Stress also decreased red blood cell (P < .01) and liver (P < .05) alpha-tocopherol content in cattle supplemented with vitamin E. Tissue alpha-tocopherol concentrations were reduced by stress only when a diet adequate in vitamin E was fed. In addition, in most sampled tissues, stress did not affect alpha-tocopherol concentrations.
authors.affiliation: Department of Animal Sciences, Colorado State University, Fort Collins 80523, USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Nockels
authors.forename: K G
authors.initials: KG
authors.lastname: Odde
authors.forename: A M
authors.initials: AM
authors.lastname: Craig
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000378:metabolism*; D003402:Creatine Kinase / Q000097:blood; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D005527:Food, Fortified; D006854:Hydrocortisone / Q000097:blood; D008099:Liver / Q000737:chemistry* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000378:metabolism; D012643:Selenium / Q000097:blood; D013312:Stress, Physiological / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D014508:Urea / Q000097:blood; D014810:Vitamin E / Q000032:analysis* / Q000097:blood / Q000494:pharmacology*
chemical_list: D014810:Vitamin E; D014508:Urea; D003402:Creatine Kinase; D012643:Selenium; D006854:Hydrocortisone