Failure of oestradiol administration to induce fatty liver haemorrhagic syndrome in the laying hen

Studies were carried out to investigate whether the administration of oestradiol to laying hens induced fatty liver-haemorrhagic syndrome (FLHS). Short term oestradiol administration (up to 6 d) significantly increased liver size and plasma lipid concentration but had no effect on liver lipid concentration or hepatic lipogenic enzyme activities. Longer-term hormone treatment (up to 28 d) again significantly increased liver size and plasma lipid concentration. Liver lipid concentration was substantially reduced and lipogenic enzyme activity significantly reduced in oestradiol-treated birds. These effects had some similarities to those seen in oestrogenised immature birds and were additive to the effects of endogenous oestrogen in the laying bird. There were no deaths from FLHS and oestradiol treatment did not cause liver haemorrhages or affect egg production.