[Evaluation of blood parameters from dairy cow stock with fertility disorders]

The evaluation is based on 1329 blood samples from 199 farms using the offer of a fertility and feeding advisory programme. Total bilirubin, AST (GOT), GLDH, glucose, urea, inorganic phosphorus, and beta-carotene served as parameters. Considerable variations of all the parameters depending on the lactation level could be demonstrated. The problem of standardisation is discussed. Increased total bilirubin values (acute metabolic stress) often occurred one or two weeks post partum (26.9% of the cows). During lactation, the marginal value was exceeded by 24.6% of the cows. AST (GOT) values beyond the standard were seen in 19.4-30.1% of the cows, depending on the lactation level. These liver diseases were verified by a 25.5% increase in GLDH-values. Hypoglycaemic cows ranged between 18.5 and 28.5%. Oversupply of proteins shows a decreasing tendency (25.7%). During the winter months the beta-carotene supply is still a problem, with 40% of the cows not reaching the standard values.