Unique Seminal Quality in the South African Cheetah and a Comparative Evolution in the Domestic Cat
Biology of Reproduction
Analysis of 40 semen samples collected by electroejaculation from 18 cheetahs revealed no major differences in seminal traits among Transvaal, South West (Namibia) or hybrid (Transvaal X South West) males. However, mean spermatozoal concentration (14.5 X 106 spermatozoa/ml of ejaculate) and percent motility (54.0%) were less in cheetahs than in domestic cats (147.0 X 106 spermatozoa/ml of ejaculate, 77.0% motility) subjected to the same electroejaculation regimen. On the average, cheetah ejaculates contained 71.0% morphologically abnormal spermatozoa compared to 29.1% aberrant spermatozoal forms in the domestic cat. These results indicate that seminal characteristics in the cheetah are markedly inferior compared to the domestic cat, particularly with respect to the incidence of pleiomorphic spermatozoa. Because a recent parallel study demonstrates that the cheetah lacks genetic variation, it appears likely that spermatozoal abnormalities are a genetic consequence of genomic homozygosity characteristic of this endangered species.
Wildt, David E.; Mitch E. Bush; J. G. Howard; Stephen J. O'Brien; D. G. Meltzer; Ann van Dyk; H. Ebedes; and D. J. Brand. 1983. "Unique Seminal Quality in the South African Cheetah and a Comparative Evolution in the Domestic Cat." Biology of Reproduction 29, (4): 1019-1025. doi:10.1095/biolreprod29.4.1019.