The Blood Proteins of Pregnant Ewes and How They are Affected by Protein in the Ration

A total of 992 blood samples of pregnant ewes fed various kinds and amounts of protein were analyzed for oxyhemoglobin, total serum proteins, serum albumins and serum globulins. Considerable variation was found in these constituents between individual sheep and between bi-weekly samples from the same ewe. Ewes fed rations low in protein had lower serum albumins than those fed a liberal or adequate amount of protein. Low protein rations also caused a reduction in oxyhemoglobin. Serum globulins were not affected by the rations fed. When fed at an equal level of protein there were no differences in blood proteins between ewes fed linseed meal and those fed dried skim milk as the protein supplement. Ewes with high oxyhemoglobin levels tended to have high serum albumins and low serum globulins. In these experiments serum globulins predominated over serum albumins. The oxyhemoglobin, total serum protein and serum globulin levels of individual ewes were highly correlated between years.