EFFECT OF SUPPLEMENTAL VITAMIN-E AND SELENIUM IN THE DIET ON VITAMIN-E AND SELENIUM LEVELS AND CONTROL OF OXIDIZED FLAVOR IN MILK FROM HOLSTEIN COWS

Twenty-four mid-lactation Holstein cows of mixed parity were used in a 2 x 2 factorial design to examine the effects of vitamin E and Se sup plementation on performance, levels of anti-oxidants in milk and resis tance of milk to oxidation. Only a proportion of cows (25%) produced m ilk susceptible to oxidation; however, there was a trend (P = 0.11) to ward reduced oxidized flavor when vitamin E was given. Milk production was increased when either vitamin E or Se were given alone (P = 0.056 ). Supplementation with 8000 IU dl-alpha-tocopheryl acetate d-1 approx imately doubled alpha-tocopherol concentration ir blood and milk (P < 0.001). Se supplementation with Se-enriched yeast at 5 mg d-1 increase d Se levels in milk from 13.2 to 34.7 mug L-1 (P < 0.001).