The sugar and total ketone content of the blood of ewes and of their new-born lambs

Abstract

IN many animals it has been found that the matemal blood at term contains a higher percentage of sugar than the foetal blood. Needham [1931] cites data illustrating this point and gives figures obtained in human subjects by 18 investigators, from which the following averages have been calculated: maternal blood 118 mg., foetal blood 94 mg. sugar per 100 ml. Aron [1924] records even wider differences for the dog (maternal 110 mg., foetal 65 mg. per 100 ml.) and for the guinea pig (maternal 107 mg., foetal 60 mg. per 100 ml.). On the other hand he gives data for the cow (maternal 100 mg., foetal 110 mg.) and for the pig (maternal 100 mg., foetal 139 mg.) which suggest that the reverse is true for these species. Passmore & Schlossman [1938] record a similar relation for sheep and goats.In the course of a study on the occurrence of ketonaemia in pregnant ewes the opportunity was taken to determine the sugar and total ketones present in the blood of ewes (both normal and ketonaemic) at the time of parturition and in that of their new born lambs. A number of ewes were available which, for some weeks during the latter half of pregnancy, had shown progressively increasing ketonaemia accompanied by marked hypoglycaemia. The lambs from these ewes were small and weak and it was of interest to see whether this weakness could be correlated with a low blood sugar level and/or the passage of ketones from the maternal to the foetal blood stream. As controls a number of healthy ewes with their vigorous new-born lambs were also examined. METHODSBlood sugar: Somogyi's modification of the Shaffer-Hartmann method [Peters & Van Slyke, 1931].