Determination of blood serum calcium, inorganic phoshorus and magnesium in different productive stages of holstein dairy cows

Introduction. The aim of this study was to determine and compare levels of blood serum calcium, inorganic phosphorus and magnesium in the peripartal period and during mid lactation in Holstein dairy cattle. Materials and Methods. Blood samples were collected from 12 cows in late pregnancy, 12 early lactation cows, and 12 mid lactation cows. Results and Conclusions. Serum calcium and inorganic phosphorus in blood of dairy cows in early and mid lactation were significantly lower compared to the values in the blood serum of dairy cows in late pregnancy, probably indicating the increased use of these macro elements by the mammary gland at the early stages of lactation. When the cows were in the lactation period, blood serum magnesium levels were significantly lower compared to the values of dairy cows during late pregnancy, probably indicating the increased use of magnesium by the dairy cows during lactation. The results show that the homeostasis of the macro elements examined in the blood of transition and mid lactation dairy cows was maintained, suggesting their adequate supply from alimentary sources.