Field Observations on the Lipids of Cows with Depressed Milk Fat Test

Abstract
Blood and milk lipids from cows with butterfat depression were sampled and analyzed. The triglycerides of milk fat were normal in fatty-acid composition, while the the free fatty acids in milk showed a high proportion of short chain fatty-acids indicating that the problem does not result from an acetate shortage. Blood lipids were significantly altered in composition. Many unknown peaks (10) comprising up to 40% by weight of the fatty-acids in certain lipid fractions were evident by gas chromatography. Overall the blood lipids were deficient in the level of stearic acid, a normal blood component in the ruminant.