[Discriminant analysis applied to blood components in dairy cows before and after delivery]

Ten blood properties--total protein, cholesterol, zinc turbidity test, leucine amino peptidase, alkaline phosphatase, lactate dehydrogenase, hemoglobin, hematocrit, and red and white blood cell counts--were measured in primiparous cows at three different stages near parturition, 260 days of pregnancy, 5 days and 35 days after parturition. Experiments were performed in two seasons, winter (January to April) and summer (June to September), using eleven cows in each seasonal group. The degree of inclusive variation of the ten blood properties by discriminant analysis was low in winter and very high in summer between 260 days of pregnancy and 5 days after parturition. It was high in both seasons between 5 days and 35 days after parturition. In addition, in comparison between the corresponding stages in the two seasonal groups, the degree was higher in summer than in winter. The discrepancy in the seasonal patterns seemed to occur by the differences in environmental factors, such as temperature and feeding conditions, in addition to stresses due to pregnancy, parturition and lactation. It was verified that discriminant analysis, one of the multivariate analyses was useful for an inclusive, objective judgment on data of multiple clinical examinations in dairy cows.