Relationships between liver blood markers and milk parameters in cows

ABSTRACT Monitoring through hematochemical liver measurements in high-yielding cows allows assessing herd well-being and health. Therefore, the present study aims to evaluate the relationships between liver blood markers and milk parameters in cows during the 1st and 2nd third of lactation. A total of 124 samples from Holstein cows (62 cows/group) belonging to nine intensive dairy farms and the same diet were used. Glucose, aspartate aminotransferase, albumin, alanine aminotransferase, milk fat, solids-non-fat, milk protein and cryoscopic point showed differences between groups. Total bilirubin, conjugated bilirubin, urea, cholesterol, γ-glutamyl-transferase, milk density, somatic cell count, and pH do not show differences between the 1st and 2nd third of lactation. Positive relationships between total bilirubin with conjugated bilirubin and cholesterol, solids-non-fat and milk protein, milk fat and glucose, solids-non-fat and albumin, milk protein and albumin, pH and urea, and somatic cell count with alanine aminotransferase were found. Negative relationship between alanine aminotransferase and γ-glutamyl-transferase, milk fat with solids-non-fat, milk protein, and somatic cell count, and milk fat with alanine aminotransferase were identified. The results may be useful for estimating adaptations in liver function, based on the behavior of liver blood markers when milk parameters are measured daily on intensive dairy farms.