The Placental Transfer and Colostral Storage of Vitamin D in the Bovine

Abstract

The effect of a daily feeding of 100,000 I.U. of vitamin D in the form of irradiated yeast 8 weeks prepartum on the level of vitamin D in maternal blood plasma, in blood plasma and liver of the newborn calf, and in colostrum at two different seasons of the year was studied. 8 cows were started on expt. in Mar., 1946, and 9 cows in Aug., 1946, with 4 cows at each season serving as controls. An increase (not statistically significant) in the maternal blood plasma level of vitamin D was noted after the feeding of vitamin D. No consistent differences were noted in the level of vitamin D in the blood plasma or liver of the newborn from supplemented dams or control dams. The colostral level of vitamin D was statistically higher per gram of colostral fat and per pound of colostrum in those cows receiving the vitamin D supplement, as indicated by assays on a composite sample from the first 6 milkings postpartum. The levels of vitamin D were significantly higher in the fall (Aug.) as compared to those values found in the spring (March). The unsuccessful results in increasing fetal storage of vitamin D are thought to be indicative of the need of higher levels of prepartum supplementation with vitamin D.