Cheetah Semen Is Much Worse Than Domestic Cat Semen

Michael -
I would like to further clarify a few things.
Sperm morphology, motility and other parameters of an ejaculate are characteristic of an individual's spermatic phenotype, e.g. normospermic (< 60% normal sperm) or teratospermic (> 60% normal sperm). This phenotype will dictate the quality of the ejaculate throughout the male's life. Populations of animal species will have proportions of each phenotype, and it is suggested that as populations and genetic variability continue to decline, the proportion of the phenotypes can be skewed toward teratospermia. There are teratospermic domestic cats, humans, and males in most species that have the same quality of semen as teratospermic cheetah, so it is not necessarily that the entire species is normo- or teratospermic. Additionally, of the Siberian tigers that have been analyzed, the ejaculate quality suggests this species has a higher proportion of normospermic than teratospermic individuals (Pukazhenthi et al, 2006; Theriogenology 66:112-121).
It is not correct to describe the cheetah as containing a "fragile genetic make-up". It has low genetic variability and is highly specialized which are correlated to a higher risk of extinction due to the susceptibility to the same illnesses and a lack of ability to adapt to changing environments - something human beings are rapidly doing by introducing new species into ecosystems that spread disease and have no natural predators, displacing native wildlife with domesticated livestock, etc.
"Abnormal" sperm morphology can refer to many things, some of which do not necessarily interfere with fertility, e.g. cytoplasmic sperm droplets, but would not normally be seen on a normal spermatozoon. Sometimes these abnormalities can be induced by the medium, e.g. coiled tails, or method used to collect the sample, e.g. cytoplasmic droplets. Abnormalities which occur during actual spermatogenesis, like abnormal acrosomes or cephalic characteristics, would actually interfere with fertility and are seen to be a problem at a higher, potentially genetic, level.
Finally, the method is termed electroejaculation, and the probe is specifically designed for a species by taking measurements and tailoring the probe to maximize the surface area contact with the rectum while not causing damage. This is incredibly important in other taxa with intestines prone to perforation. Please be careful when describing this to others, as it can be misconstrued. Many people do not understand how difficult it is to breed non-domestic cats in captivity, and because human beings are not willing to stop breeding (as you pointed out), semi-drastic measures are required to aid natural breeding.

Hi Tracey, it is said that the original reason for inbreeding goes back tens of thousands of years but modern trends of population decreases only serves to compound the problem. Habitat loss is one reason for lower populations. Cheetah are also shot as they often live on farmland.

The Siberian tiger also has inbreeding problems as do captive tigers and all captive cats for that matter.

I only see one way, down, for all of the wild cats as long as the human population goes up - its logical.

Hi Michael

I was very interested in your article however I've not yet had chance to read all the links.

Could it also be that the cheetahs natural habitat is slowly dissapearing thus forcing them closer togeather which is increasing interbreeding on the whole?

Our domestic cats are very adaptable generally whereas a Cheetah can only survive in certain circumstances or in captivity.

When their natural habitat is disrupted surely this can affect so much i.e. food sources, increase in predators on their young etc.

A domestic cats way of life can be turned completely upside down and yet he can adapt and survive, mainly because he has more at his disposal.

This is just my opinion however I'm certainly no expert!