Studies on the pathogenesis of fatty liver in cows

Abstract

Increased fat mobilization in early lactation in cows is described by many authors. Energy deficit in connection with the start of milk secretion is considered to be of importance as cause of the lipolysis. One consequence of increased mobilization of body fat can be development of a fatty liver.

In an in vitro of lipid metabolism in bovine adipose tissue McNamara and Hillers have shown that there is an adaptation in prepartum. There is a strong reduction in lipogenesis and esterification and increase in norepinephrine- and epinephrine-stimulated free fatty acid release. The lipoprotein lipase activity in adipose tissue decreases and increases in the mammary gland. This metabolic shift precedes the energy demand for lactation and is stimulated by prolactin and inhibited by progesterone. At two months postpartum there is a dramatic rebound in lipogenesis and esterification.

Besides the increased transport of fatty acids to the liver near partus, decreased removal of fat from the liver can be of importance in the development of fatty liver. The aim of the present investigation was to elucidate the pathogenesis of fatty liver in cows by analysing serum lipoproteins and plasma lipids in normal cows round partus on different prepartum feeding and in cows with fatty liver.