Bacterial endotoxins and the pathogenesis of fatty liver--haemorrhagic syndrome in the laying hen.

A high energy maize diet produced a higher incidence of fatty liver-haemorrhagic syndrome than a low energy barley diet when the diets were fed during the summer. The triglyceride content of the liver increased with the liver haemorrhage score and in hens with the highest scores there was evidence of hepatic hyperplasia. They also had high activities of aspartate transaminase and cholinesterase in the plasma and a low activity of sorbitol dehydrogenase. There was no increase in plasma endotoxin levels as the syndrome developed or any significant variation in these levels with the haemorrhage score, the triglyceride content of the liver or plasma enzyme activities. It was concluded that the steatosis does not impair the ability of the liver to inactivate endotoxins of enteric bacteria and that these toxins are not involved in the pathogenesis of the syndrome.