Medycyna Wet. 63 (6), 662-666, 2007
Špakauskas V., Klimienė I.
Levels of parathyroid hormone, calcium, phosphorus and magnesium in blood sera of healthy and sick cows
The blood levels of parathyroid hormone (PTH), calcium, phosphorus and magnesium were examined in 122 cows, which included healthy cows as well as cows with osteomalacia and paresis. Levels of PTH were determined in vitro using IMMULITE analyzer, levels of macroelements - using the automated ,,Eos-Bravo” analyser with Hospitex reagents. The blood level of PTH ranged from 1.7 to 7.5 pmol/l in healthy cows and from 3.95 to 20.19 pmol/l in sick cows. The highest and most significant increase in blood PTH level (up to 18.31 ± 1.88 pmol/l) was found in cows with parturient paresis. The blood serum levels of PTH in healthy cows changed depending on age and on the physiological status, being significantly lower in cows 2-4-years-old compared with cows 8-years-old and over. The levels of PTH were significantly higher in cows-in-calf and heifers-in-calf compared with cows of the lactation period. Higher levels of PTH were found during the winter than in the summer. The blood level of PTH correlated inversely with the level of calcium in cows with osteomalacia (r = -0.89) and with parturient paresis (r = - 0.49-0.61). The blood serum PTH levels were significantly increased in all groups of cows (p<0.05) on the day of parturition and one day after parturition compared with the measured PTH level 5 days before parturition. Vitamin D (injected 3-5 times) administered during the last days before calving effectively increased the levels of calcium, phosphorus and PTH.
Keywords: cows, parathormon, osteomalacia