The lipid composition of erythrocytes in European cattle and buffalo steers.

This study compared the lipid composition of the red blood cells of European cattle and of buffalo steers at the same level of feed intake in a thermoneutral environment. The mean volumes of the erythrocytes and their lipid content were greater in buffalo than those in cattle. However, the amounts of phospholipid and cholesterol in cells of equal volume were higher in buffalo than in cattle. In contrast, the phospholipid level at a given cholesterol level was higher in cattle than in buffalo. The distribution of the different molecular species of phospholipids in the red cells of the two breeds were similar, but there were significant distinctions in their fatty acid patterns, notably in the levels of 24:0 and 24:1 in the sphingomyelin fractions. The proportion of total monounsaturated acids in the erythrocytes were similar from both breeds. However, there was a higher percentage of polyunsaturated fatty acids with a corresponding lower content of total saturated fatty acids in the red cells from buffalo than in those from cattle. The breed differences in erythrocyte lipid composition are discussed in relation to breed differences in red cell characters and could lead to a better understanding of the mechanisms of environmental adaptation.