Inline changes in lactate dehydrogenase, milk concentration according to the stage and number of lactation periods, including the status of reproduction and milk yieldin dairy cows

The aim of the present study was to investigate inline lactate dehydrogenase (LDH) dynamic changes based on different cow factors - number and stages lactation, milk yield, status reproduction in clinically healthy dairy cows. In Herd Navigator system, LDH activity levels (μmol/min per litre) were measured using dry-stick technology. A total 378 cows selected. According their reproductive status, classified as belonging following groups: Fresh (1 44 days after calving); Open (45 65 Inseminated 35 insemination); Pregnant (35 60 insemination pregnant). productivity, into ⟨15 kg/day, 15 25 kg/day >35 kg/day. milked with a DeLaval milking robot (DeLaval Inc. Tumba Sweden) combination analyser (Lattec I/S. Hillerod Denmark). conclusion concentration may increase together rise lactation period frequency. highest level determinated group fresh ranged from 5 10 DIM, while found milk. Thus, there positive relationship between yield.