Abstract
Mammary uptakes of glucose and long-chain fatty acids are proposed to be the major metabolic determinants of milk volume production and mammary efficiency, respectively. The ratio of glucogenic to lipogenic nutrients in the diet is proposed to be the major determinant of spontaneous ketosis. Experimental evidence and clinical observations are adduced in support of these three interrelated propositions. Their heuristic value would be demonstrable in tests of formulations of high-fat rations and administrations of articles, such as growth hormone preparations, intended to promote maximal production and efficiency with least risk of ketosis.