Vitamin E and Selenium work together in cattle rations to support many functions. The two nutrients are interdependent to be effective. No different than a belt and pulley. This article will focus on the impact of supplementation levels on the immune response provided to newborn calves.
Growing forages have high levels of fat soluble Vitamin A and E precursors. When hay is in storage, these precursors are oxidized and after 6 months of storage, the amount the cow receives is variable. If forages are ensiled, these vitamins are destroyed during the fermentation process. In both cases, 100% of the daily requirements should be provided by feed supplementation. In late pregnancy, it is recommended to provide 3 mg of Selenium and 300 International Units (IU) of Vitamin E to the cow daily.
Vitamins and Selenium are needed to produce antibodies which are found in the first milk or colostrum. Colostrum is developed 4 to 6 weeks prior to calving, thus the need for supplementation is well before the calf is born. The majority of Vitamin E and Selenium is passed to the calf through colostrum. Very little Vitamin E is transferred through the placenta to the unborn calf.
Antibodies provide passive immunity to the newborn and must be consumed by the calf within the first 6 hours of life. At 6 hours, the holes in the rumen wall start to close and it becomes more difficult for the large antibodies to get into the blood stream. By 12 hours after calving, the holes are closed and colostrum cannot cross.
Injecting the calf with Vitamin E and Selenium does provides additional nutrients to the calf, but it does not improve the immunity status. If there are health problems within the first week after calving, the amount of antibodies passed on from the cow to the calf via colostrum was not sufficient. One possible cause is an inadequate nutrition program for the pregnant cows and should be re-evaluated.
For additional information, contact Barry at 403-741-6032.
Photo credit: Nora Paulovich