Abstract
As the background of frequent disease onset noted from the herd test for 28 high milk producing cows yielding 9631kg per head annually on the average, it was found that 16 animals out of 26 (61.5%) showed vitamin E (VE) concentration in blood lower than 4μg/ml individually. Reduction of Selenium (Se) was noted on 3 animals (11.5%), association of which with the lower concentration of VE made the lesion further aggravated. Physiological changes of the VE level in blood were noted in the aged animals as well as those before or after the delivery, or deficiency in internal maintenance invited further decrease of the same as the performance was higher. The animals showing subclinically low level of VE can be seen in parallel to those in good health and those in the line of high performance, which reveals that differences are observed by strains and by individuals. In the milk cows with high performance, specially in the lines of PF and ABC, there were much more animals with vulnerable constitutions compared with those of other strains, more than a half of them being subclinically holding the low level of VE. It was also differentiable by strains. Accordingly it can be identified as the respective constitution. As the background of frequent onsets of diseases, there exist subclinical decrease of VE in blood together with the vulnerable constitution as causal factors, therefore, as the radical ways of preventing frequent disease onsets it is considered important to dose VE and Se specially in the pre-and postpartum periods for the diseases reactive with VE and Se, or mixing them in the feed, as well as to avoid inbreeding on the basis of mating for improving the constitution.
