Serum Parathyroid Hormone Levels and Mineral Profiles in High Producing Dairy Cattle Around Calving Period

The aim of this study was to attempt at providing a complete picture of dynamics of selected biochemical blood parameters (parathyroid hormone, Calcium, Phosphorus, Sodium, Potassium, Chlorine and ionized calcium) around calving period in high producing dairy cattle (Holstein breed), giving new and useful information about the guidelines for the management strategies during different physiological phases. Seven pregnant Holstein cows were blocked by parity and fellow during the peri-parturient, calving and post-parturient period. Jugular blood samples were taken 8-15 days prior to expected calving, at calving and in day seven post-calving to estimate serum concentrations of Parathyroid Hormone (PTH), Calcium (Ca), Sodium (Na), Potassium (K), Chlorine (Cl) and ionized Calcium (i Ca). Results indicated that the level of PTH at calving time and in seven days post calving was significantly higher (p<0.05) than those in pre-partum and this is vice versa for blood calcium and ionized calcium. However, the levels of Na and Cl in pre-partum were significantly higher (p<0.05) than those at calving and postpartum. Other mineral levels were not significantly change over time of study. The present study indicates that serum PTH and some electrolytes could be severely altered in dairy around the time of calving.