Baby Cheetah - greatly inbreed - photo by San Diego Shooter (Flickr)
Yes, the sperm of a cheetah, the fastest land animal on the planet, is much worse than the sperm of the common domestic cat, the companion animal that you and I live with and from which we derive so much pleasure.
Eighteen cheetahs were subject to ectroejaculation. This sounds unpleasant. Ectroejaculation is a procedure that is usually carried out under general anesthetic and which is used to obtain semen samples from sexually mature male mammals. An electrode is inserted into the rectum and a small electric shock applied stimulating an ejaculation1.
The semen was obtained from Namibian and Transvaal cheetahs. Namibia is the home of the cheetah but populations are declining all the time (cheetah habitat).
Spermatozoal concentration and motility levels in the cheetah were one tenth of those of the domestic cat, on my reading of the data. Also the number of 'aberrant spermatozoal forms' where considerably higher in the cheetah compared to the domestic cat - 71% to 29.1%. 'Motility' means: the ability to move spontaneously and actively, consuming energy in the process2
Cheetah semen is 'markedly' inferior to that of the domestic cat. There is a much higher incidence of spermatozoa that takes on a different shape or that is a variation from the normal (= abnormal sperm, as I understand it).
The much higher level of genetic abnormalities in the cheetah are put down to inbreeding in the cheetah that has resulted in genetic homoygosity (the possession of two identical forms of a particular gene, one inherited from each parent). It said that one cheetah is almost a clone of another. The cheetah is higly inbreed. This increases the chances of mutant recessive genes becoming effective in producing unwanted phenotypes.
Why is the cheetah inbreed? Does this result in less virile animals? Does it further endanger this already endangered wild cat?
The inbreeding it is thought is a result of a population crash thousands of years ago. The Siberian tiger suffers from inbreeding reducing its fertility. There are 400 Siberian tigers but the population from a breeding standpoint equates to just 35 tigers (see Siberian tiger habitat). Is is argued that poor sperm causes infertility (see also male wildcat roaming).
There are arguments about the cheetah and how its fragile genetic makeup affects is prospects of survival. Some say it makes no difference. But one thing is for sure, on a classic measure of genetic health, the humble domestic cat is far healthier and is far better placed to survive.
There are about 500 million domestic cats in the world and there are 7,500 adult cheetahs3. You decide.
Major source: Unique seminal quality in the South African cheetah and a comparative evaluation in the domestic cat by: D E Wildt, M Bush, J G Howard, S J O'Brien, Meltzer, A Van Dyk, H Ebedes and D J Brand