Estimation of metabolic status in high yielding dairy cows during transition period and full lactation
Djokovic, RadojicaCincovic, MarkoIlic, ZoranKurcubic, VladimirAndjelic, BiljanaPetrovic, MilosLalic, NebojsaJasovic, Boban
Background: Major changes in the metabolic functions in high-yielding dairy cows occur during the transitional periodand during lactation. Parturition and lactogenesis are accompanied by many physiological changes that facilitate themaintenance of homeostasis Consequently, physiological situations leading to a negative energy balance are coupled to anincreased uncontrolled rate of body fat mobilisation and the increased fatty acids accumulation in hepatocytes and bloodketone bodies, resulting in disturbances of the morphological and physiological liver integrity. The objective of the presentstudy was to estimate metabolic status in late pregnant, early lactation and full lactation Holstein dairy cows on the basischanges of blood concentrations of selected biochemical markers.Materials, Methods & Results: The experiment included 36 Holstein cows. Three groups of clinically healthy cows werechosen from the herd. Group 1 consisted of late pregnant cows (n = 12) from 30 to 1 day (20 ± 15) to partus; Group 2comprised early lactation cows (n = 12) in the first month of lactation (15 ± 12 days), and Group 3 included full lactationcows (n = 12) between 60 to 90 days of lactation (81 ± 30 days). Blood samples were collected from all cows, by punctionof the jugular vein. Biochemical testing for markers in the blood serum showed significantly lower values (P < 0.05) ofglucose, TG, Tchol. and urea in early cows than in full lactation and late-pregnant cows. The blood concentration of NEFAand BHB was significantly increased (P < 0.05) in the group of cows in early lactation compared to the other groups ofcows. The mean tBIL. concentration and the serum AST, GGT and ALT activities were markedly increased (P < 0.01)in the lactation cows compared to the late pregnant cows. Furthermore, the intensity of lipomobilisation (NEFA or BHBconcentrations) correlated positively (P < 0.05) with the markers of cell damage or liver function impairment (tBIL., serumAST...(AU)
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