its initial isolation fromGibberella zeae, the perfect stage ofF. graminea-
rum.
In gilts, the vulva and mammary glands become swollen and, in severe
cases, there may be vaginal and rectal prolapse. In older animals there
may be infertility, reduced litter size and piglets may be born weakened
or even deformed. There is concern about the long-term exposure of the
human population to such an oestrogen.
Zearalenone, and the corresponding alcohol zearalenol, are known to
have anabolic, or growth promoting activity, and, although its use as a
growth promoting agent is banned in some countries, it is permitted in
others. This can lead to problems in international trade because zear-
alenone can be detected in the meat of animals fed on diets containing it.
8.4.4.4 Oesophageal Cancer. In parts of Northern China, and the
Transkei in Southern Africa, there are regions of high incidence of
human oesophageal carcinoma and the epidemiology of the disease fits
the hypothesis that the consumption of moulded cereals and mycotoxins
are involved.F. moniliforme(by the strict code of biological nomencla-
ture this should now be called F. verticillioides), which belongs to a
distinct group of the genus which do not produce trichothecenes, seems
to be the most likely fungus to be involved. Strains of this species are
associated with a disease of rice which has been a particular problem in
China and other, probably distinct, strains are commonly isolated from
maize grown in Southern Africa and many other parts of the world.
F. moniliformeis a very toxigenic species and its occurrence in animal
feeds is associated with outbreaks of a disease known as equine le-
ukoencephalomalacia in horses and liver cancer in rats.
One of the first mycotoxins to be isolated during the study of these
diseases was called moniliformin (Figure 8.17) because it was presumed
Figure 8.16 Zearalenone
Figure 8.17 Moniliformin
Chapter 8 295