Changes of tocopherols in blood serum of cows fed hay or silage

The purpose was to determine if cows fed corn silage during gestation have calves with low serum tocopherol and high erythrocyte hemolytic rates. Ten cows were fed hay, six fed corn silage with one vitamin E injection, and six fed corn silage with no injection beginning with the 6th mo of gestation. Hay intakes were adjusted to equalize intakes of dry matter. Analysis of tocopherol isomers was by reverse phase, high performance liquid chromatography. Alpha-tocopherol and potassium were lower for hay-fed cows than for cows fed predominantly corn silage, but creatinine phosphokinase, glutamic-oxaloacetic transaminase, and glucose were higher. Calves from hay-fed cows had lower alpha-tocopherol and higher glutamic-oxaloacetic transaminase. No consistent histopathological changes of muscle tissue were seen. Erythrocyte hemolytic rates were low. Serum vitamin E of cows may change during gestation because of type of forage fed. Specific enzyme changes may give an early indication of a change of tocopherol status of cattle.