| Abstract: | The dynamics of serum vitamin E levels in heifers was followed for 22 months. We found that calves were born with a very low, almost nil, content of this vitamin (on an average 0.029 mg%) as a result of the limited diaplacental transfer from the mother to the fetus. In the following period of extrauterine life and growing up of the young cattle conspicuous age dynamics was recorded which is, however, linked or affected by the seasons. Colostral nutrition which is reflected in the increasing serum concentration of vitamin E has an important role. After the change from winter feeding rations to summer feed, consisting mainly of grazing, a marked increase in the serum concentration of vitamin E with an apex was observed, i.e. with the maximum mean value in November. In relation to the age of animals the highest concentration of vitamin E in the blood serum of heifers was recorded, expressed as mean values toward the end of our observations (0.736 mg%), i.e. in the period of sexual maturity; it equalled the concentration of vitamin E determined in cows. |
