Parathyroid Hormone Level in Blood of Cows with Different Forms of Clinical Hypocalcaemia

The research was intended to determine the parathyroid hormone (PTH) level in various forms of clinical hypocalcaemia in dairy cows with the use of the immunochemiluminometric assay (ICMA), routinely applied in humans for the measure of the hormone. The study was conducted on 59 cows of the lowland black-and-white and HF breeds, as well as crossbreds. Symptoms of clinical hypocalcaemia were confirmed in 47 animals. The symptoms occurred in the animals during the post-calving period, i.e. from several hours to about a week after calving. In the cows with clinical symptoms of hypocalcaemia the PTH level demonstrated a negative correlation with the low values of total calcium in the serum with the exception of the group of downer cows. The lowest PTH levels were confirmed in the downer cows, in which no beneficial effects of medical treatment were noted. The ICMA with human antibodies proved to be also valid for measuring the level of PTH in cows. It is relatively inexpensive and fairly quick method.