Effect of Feeding Protected Safflower Oil on Yield, Composition, Flavor, and Oxidative Stability of Milk

Four Holstein ccws were fed 800 g of safflower oil:casein:formaldehyde per day for 16 wk as supplement to a hay:concentrate diet. Four control Holstein cows were fed only the hay:concentrate diet. The safflower oil in the supplement was protected from hydrogenation in the rumen. The linoleic acid content of the milk fat was increased from a mean of 2.7% for nonsupplemented cows to 13.3% for supplemented cows. Recovery in milk fat of protected linoleic acid was 22%. Milk, fat, and protein yields and fat and protein percentages were not affected by the supplementation. No health or feeding problems were observed during the supplementation with the safflower oihcasein:formaldehyde material. Offflavors, predominately of an oxidized nature, readily developed in milk containing high linoleic acid. Supplementation of the cows with a-tocopheryI acetate or the direct addition of a-tocopherol to the milk effectively prevented development of oxidized off-flavors.