Lifetime semen production in a cheetah (Acinonyx jubatus)

• Published in: Zoo biology Vol. 20; no. 5; pp. 359 - 366
• Main Authors: Durrant, Barbara S., Millard, Susan E., Zimmerman, Dawn M., Lindburg, Donald G.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 2001
• Subjects: artificial vagina; gonadal senescence; sexual maturity
• ISSN: 0733-3188; 1098-2361
• DOI: 10.1002/zoo.1034

Lifetime semen production data provide valuable insight into a species’ natural history and biology as well as information about the potential fertility of males at various life stages. An understanding of the ages of sexual maturity, peak sperm production, and gonadal senescence will contribute to the design of species management plans for captive, free‐ranging, and reintroduced populations of exotic animals. To describe these life stages in the cheetah, semen was collected biweekly for 13 years from a solitary male beginning at 3 years of age. The 338 ejaculates were obtained noninvasively by artificial vagina. Ejaculate volume and sperm motility score, concentration, and normal morphology were recorded. A sperm quality index incorporating all five semen parameters was calculated to facilitate ejaculate comparisons. Polynomial regression analysis revealed a significant effect of age on volume, which increased throughout the animal’s lifetime except for a reduction between ages 10 and 12. Concentration was also significantly affected by age and increased from the age of 3 to the age of 10, then decreased. The sperm quality index revealed a significant effect of age as it increased from age 3 to age 8, then declined as the male grew older. The cheetah did not reach peak semen production until age 8 and continued to produce good quality semen for several more years. These data were somewhat unexpected, given the average cheetah life expectancy of approximately 7 years. Zoo Biol 20:359–366, 2001. © 2001 Wiley‐Liss, Inc.