The relationship between serum albumin concentration and body protein loss in pregnant sheep

Abstract

SummaryData are presented from 104 sheep from three separate sources (batches) in which variation in the degree of maternal body protein loss was induced by nutritional means. The change in body protein content during pregnancy was calculated as the difference between body protein content in early pregnancy, predicted from the relationship with body weight in control sheep killed in early pregnancy, and actual content on slaughter at parturition. Serum albumin and globulin concentrations and body weight were measured at intervals during pregnancy and examined for relationships with body protein change.Highly significant linear relationships were found between the change (%) in albumin concentration during pregnancy or albumin concentration in late pregnancy and the calculated change (%) in maternal body protein content (P < 0·001 in both cases) though fitting separate intercepts for each batoh of sheep led to improvements in fit.Equations for prediction of loss (%) of body protein from change in body weight or maternal body weight during pregnancy though significant, were also improved by fitting separate intercepts for batches. The relative value of the relationships for predicting body protein loss is discussed.Serum globulin concentration was not affected by protein status of the animal.