Death in broiler breeders due to salpingitis: possible role of zearalenone.

High mortality occurred in a flock of 24,000 broiler breeders. During the 40 weeks of the laying period the mortality was approximately 40% in two houses and 20% in two other houses. Peak egg production in the severely affected houses reached 51% and 56% while the two other houses achieved 66% and 76%. Fertility was not affected and the progeny appeared normal in all respects. In the affected birds ascitic fluid was found in the abdomen while cysts and a large amount of fibrinous material were present in the oviduct. The histopathological examination showed caseous cysts in the epithelium with chronic inflammation of the genital tract (salpingitis and peritonitis). Examination of feed extracts with a radioreceptor assay indicated a high degree of oestrogenic activity. Examination by thin layer and high pressure liquid chromatography indicated that zearalenone - a naturally occurring oestrogenic mycotoxin produced by Fusarium spp -was present in concentrations of up to 5 microg/g of feed.