The Fat Metabolism of the Mammary Gland of the Normal Cow and of the Cow in Ketosis

Abstract

Evidence was presented in previous publications More recent publications (24, 28) from this laboratory demonstrated for the first time the utilization of reiatively large quantities of the intermediate product of fat metabolism, ~-hydroxybutyric acid, by the mammary gland of the cow. In ketosis it was observed that this utilization was increased by over 100 per cent and would account for the total oxygen consumption of the gland if oxidized for energy purposes. The acetoacetic acid and acetone fraction was not used in measurable quantities by the gland of either the normal cow or the cow with ketosis. As it is generally assumed that most of the tissues of the body utilize both 13-hydroxybutyric acid and acetoacetic acid for energy purposes it was considered possible that ~3-hydroxybutyric acid was used in direct synthesis, and the suggestion was made that some of the short chain fatty acids peculiar to milk fat were derived from this source (27).