Dietary estrogens — a probable cause of infertility and
liver disease in captive cheetahs
Dietary estrogens — a probable cause of infertility and liver
disease in captive cheetahs.
Setchell KD, Gosselin SJ, Welsh MB, Johnston JO, Balistreri WF,
Kramer LW, Dresser BL, Tarr MJ
Gastroenterology 1987 Aug 93:2 225-33
Abstract
The cheetah in the wild is ''racing towards extinction'' mostly due
to habitat destruction. Its survival will probably depend on
accelerated captive breeding.
At this time, however, reproductive failure and liver disease
threaten the future of the captive cheetah population.
Histopathological evaluation of more than 100 cheetah livers
identified venocclusive disease as the main hepatic lesion responsible
for liver disease in this species.
Analysis of the commercial feline diet by high-performance liquid
chromatography and gas-liquid chromatography-mass spectrometry revealed
large amounts of two phytoestrogens identified as daidzein and
genistein. These compounds were found to be derived from a soybean
product that was a component of the cheetah diet, and their
concentrations both ranged from 18 to 35 micrograms/g diet.
The adult cheetah consequently consumes approximately 50 mg/day of
these weak estrogens.
When extracts of the diet were tested for estrogenicity using a
bioassay, a dose-related increase in uterine weight was observed.
In 4 cheetahs studied, withdrawal of this feline diet by
substitution with a chicken diet resulted in an improvement in
conventional liver function tests and a normalization in the appearance
of hepatic mitochondria.
We conclude that the relatively high concentrations of
phytoestrogens from soybean protein present in the commercial diet fed
to captive cheetahs in North American zoos may be one of the major
factors in the decline of fertility and in the etiology of liver
disease in this species.
The survival of the captive cheetah population could depend upon a
simple change of diet by excluding exogenous estrogen.
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