EFFECTS OF SHIPPING, HANDLING, ADRENOCORTICOTROPIC HORMONE, AND EPINEPHRINE ON ALPHA-TOCOPHEROL CONTENT OF BOVINE BLOOD

In 2 studies, plasma, erythrocyte, and neutrophil alpha-tocopherol con centrations were monitored in beef cattle after shipping, handling, an d sample collection. On the basis of alpha-tocopherol results, an addi tional 2 studies were designed to measure the effects of administratio n of adrenocorticotropic hormone (ACTH) and epinephrine on the alpha-t ocopherol concentration in the aforementioned blood constituents and o n creatine kinase (CK) activity in Holstein calves. In the first of th ese studies, 15 beef cattle that had recently arrived at the feedlot c onsumed feed supplemented daily with 1,000 IU of dl-alpha-tocopheryl a cetate. Values for initial blood samples indicated that CK activity wa s high. Although plasma alpha-tocopherol concentration indicated that vitamin supplementation was adequate, RBC and neutrophil alpha-tocophe rol values were generally nondetectable. After 4 weeks of supplementat ion, plasma alpha-tocopherol concentration. increased (P < 0.05), and neutrophil and RBC alpha-tocopherol values became measurable in most o f the cattle. In the second study, 6 beef heifers had decreased (P < 0 .05) plasma, RBC, and neutrophil alpha-tocopherol values after multipl e periods of handling and blood sample collection. In the third and fo urth studies, 10 tamed Holstein heifer calves, 5 of which were adminis tered ACTH and epinephrine to simulate stress effects on blood alpha-t ocopherol concentrations and CK activity. In study 3, the vitamin E-ad equate heifers had increased blood CK (P < 0.001) activity and cortiso l (P < 0.01) concentration, and decreased (P < 0.05) neutrophil alpha- tocopherol concentration after hormone injections. In study 4, when vi tamin E-deficient calves received the aforementioned hormones, CK acti vity increased (P < 0.05) and RBC alpha-tocopherol concentration decre ased (P < 0,05), whereas plasma and neutrophil values did not change. These results indicate that shipping and handling, or the stress parad igm of ACTH and epinephrine injections, may reduce the alpha-tocophero l content of plasma, RBC, and neutrophils while increasing plasma CK a ctivity, which indicates membrane destruction.