Tiie effect of linoleic acid and/or vitamin e supplementation of calves on plasma vitamin status, erythrocyte membrane fatty acid composition and oxidation of membrane lipids

Abstract

The vitamin E (Vit E) requirement of the neonatal calf is largely dependent upon its dietary intake of polyunsaturated fatty acid (PUFA) The PUFA content of neonatal calf plasma is low, the plasma triene:tetraene ratio of approximately 0.96 suggests a possible essential fatty acid deficiency, however within 3-4 days postpartum the ratio is markedly reduced to approximately 0.12 (Noble 1984). In spring-calving cows turned out to grass just prior to calving the sudden change to a diet rich in PUFA has a significant influence on the PUFA content of colostrum and milk and thus the Vit E requirement of the newborn calf. A study was conducted to examine the effects of different dietary ratios of Vit E to C18:2 on the growth performance; immunoglobulin status; fatty acid and retinol, Vit E and β-carotene profiles of blood plasma and erythrocyte membrane lipids (EML), and lipid oxidation of erythrocyte membranes. The effect of turn-out to grass on cow plasma fatty acid composition was also studied. The preliminary results of this study are presented below.