[Ionized calcium and total calcium in the blood of cattle, sheep, swine and horses of different ages, reproductive stages and uses].

Concentrations of ionized calcium (Cai) in blood and of total calcium (Ca(t)) in serum were determined in 99 cattle, 58 sheep, 74 pigs and 59 horses of different age groups and reproductive periods as well as kinds of use of the animals. The values of Cai in blood in the groups taken into account for comparison of species decreased significantly in the order dairy cows < ewes < sows < horses. In cattle and pigs, there were significant differences in the Cai-level, according to age with the youngest animals having the highest values. In cows from the fourth lactation onward, one day post partum (p.p.) the smallest concentrations were measured, differing significantly from animals in other reproductive periods. In ewes, the lowest values were estimated one week before parturition. The level of Cai in blood of sows decreased between day one and 6 weeks p.p. significantly. No significant differences could be demonstrated between the different groups of horses. With regard to the concentrations of total Ca, differences between the groups were not so clear as with Cai.