[Behavior of calcium, inorganic phosphorus, magnesium and glucose concentrations in the plasma of ewes in the perinatal period].

Blood samples were taken from 40 ewes in a flock of the Merino meat breed at the spring lambing once daily from five days before lambing to 3-4 days afterwards. Blood calcium ranged from 9.4 to 10.8 mg/100 ml, phosphorus between 3.6 and 4.9 mg/100 ml and magnesium from 2.1 to 2.6 mg/100 ml. There were no statistically significant changes in mineral concentrations at the time of parturition. Plasma glucose increased as parturition approached, averaging 46 mg/100 ml five days before lambing, twice this figure at lambing, followed by a rapid fall to pre-lambing values. A comparison with similar observations in cows showed that there was no essential difference in blood glucose between the two species, but there were considerable differences in the concentrations of minerals, attributable to differences in average age of the groups of animals examined, and to the higher milk yield of cows.