Blood serum levels of calcium, inorganic phosphorus, magnesium and the correlation between calcemia and alkaline prosphatase during pregnancy of the thoroughbred mares

Abstract

In this work the blood serum levels of calcium, inorganic phosphorus, magnesium and correlation between calcemia and alkaline phosphatase during pregnancy of the thoroughbred mares have been carried out. Samples of blood have been collected from 12 mares in different periods of the pregnancy as well as between 10-30 days post partum. Total calcium and magnesium were determined by the TODD method; the inorganic phosphorus by the FISKE-SUBBAROW technic and the alkaline phosphatase by the KING ARMSTRONG technic. The mean values in mg % of the total calcium from the gestation periods of 230 to 280 days (X = 11,213), of 280 to 330 days (X = 11,155) and of 10 to 30 days after foaling (X = 11,051), have shown statiscal significance difference from the periods of 30 to 80 days (X = 11,857), of 80 to 130 days (X = 11,632), of 130 to 180 days (X = 11,845) and of 180 to 230 days (X = 11,935). As has been shown, pregnant mares, especially during the advanced stages of pregnancy, as well as some days after foaling, showed a tendency toward reduction in total blood serum calcium. The mean values in mg % of the inorganic phosphorus, indifferent periods of gestation were as follow: 30 to 80 days (X =5,475); 80 to 130 days (X = 6,366); 130 to 180 days (X = 5,866); 180 to 230 days (X = 5,558); 230 to 280 days (X = 5,341); 280 to 330 days (X = 5,933) and 10 to 30 days after foaling (X = 5,858). These results have not shown statistical significance difference among them. The mean values in mg % of the magnesium, in different periods of gestation, were as follow: 30 to 80 days (X = 2,086); 80 to 130 (X = 2,273); 130 to 180 (X = 2,218); 180 — 230 (X = 4,328); 230 to 280 (X = 2,448); 280 to 330 (X = 2,424) and 10 to 30 days after foaling (X = 2,195). Only the mean value from the period of 30 to 80 days has shown statistical significance from all the other ones. The mean values of the total calcium taken between 280 to 330 days of pregnancy and between 10 to 30 days after foaling, when correlated with the mean values of the blood serum alkaline phosphatase from the same periods of the pregnancy (see Rev. Fac. Med. Vet. S. Paulo, 8: 445, 1970), have shown statistical significance at the level of 5% (r = 0,83) by the Pearson correlation coefficient.