[Long-term trends in the metabolic profile test results in German Holstein dairy herds in Thuringia, Germany]

Systematic metabolic profile tests at regular intervals provide important information to meet the increasing challenges in managing dairy herds. This study aimed at deriving long-term trends from the results of metabolic profile tests in Thuringian German Holstein dairy herds.

Blood and urine samples were collected from 710 fresh, high yielding, and dry cows, respectively, to monitor 13 parameters including the serum non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), bilirubin, β-carotene and urea concentrations, the serum of aspartate aminotransferase and glutamate dehydrogenase activities, the serum concentrations of the minerals calcium, inorganic phosphate and selenium, the urine potassium and sodium concentrations, and the net acid-base excretion (NABE). A total of 17,070 group samples from 103 herds were collected during 1997-2014. Period prevalence of aberrant groups was calculated for each parameter and year accordingly. Using a linear regression model, a long-term trend of the period prevalence was determined.

To account for the 15 aberrancies possible for each stage of lactation, seven significant trends were found for dry, nine for fresh, and ten for lactating cows. A decrease of the period prevalence was detected for increased NEFA, for low serum β-carotene, selenium, inorganic phosphate, and urea concentrations, for low sodium and high potassium urine concentrations, and for increased NABE. In contrast, period prevalence increased significantly for cases with increased serum aspartate aminotransferase and glutamate dehydrogenase activities, increased bilirubin concentration, and low NABE.

Metabolic profile tests enable a description of the herd health status using objectively measured data as a basis for the implementation of measures to optimize herd management to improve the herd health status.