Age-Dependent Changes in Sperm Production, Semen Quality, and Testicular Volume in the Black-Footed Ferret (Mustela nigripes)1

The black-footed ferret (Mustela nigripes), which was extirpated from its native North American prairie habitat during the 1980s, is being reintroduced to the wild because of a successful captive-breeding program. To enhance propagation, the reproductive biology of this endangered species is being s...

Full description

Saved in:
Bibliographic Details
Published in:Biology of reproduction 2000-07, Vol.63 (1), p.179-187
Main Authors: Wolf, K. N, Wildt, D. E, Vargas, A, Marinari, P. E, Kreeger, J. S, Ottinger, M. A, Howard, J. G
Format: Article
Language:English
Subjects:
aging
Contents
Leydig cells
male sexual function
sperm
testosterone
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The black-footed ferret (Mustela nigripes), which was extirpated from its native North American prairie habitat during the 1980s, is being reintroduced to the wild because of a successful captive-breeding program. To enhance propagation, the reproductive biology of this endangered species is being studied intensively. The typical life span of the black-footed ferret is approximately 7 yr. Female fecundity declines after 3 yr of age, but the influence of age on male reproduction is unknown. In this study, testis volume, seminal traits, sperm morphology, and serum testosterone were compared in 116 males from 1 to 7 yr of age living in captivity. Results demonstrated that testes volume during the peak breeding season was similar (P > 0.05) among males 1 to 5 yr of age, reduced (P < 0.05) among males 6 yr of age, and further reduced (P < 0.05) among males 7 yr of age. Motile sperm/ejaculate was similar in males 1 to 6 yr of age but diminished (P < 0.05) in those 7 yr of age. Males at 6 and 7 yr of age produced fewer (P < 0.05) structurally normal sperm than younger counterparts; however, serum testosterone concentrations were not reduced (P > 0.05) in older males. Histological comparison of testicular/epididymal tissue from 5- and 7-yr-old black-footed ferrets confirmed that the interval between these two ages may represent a transitional period to reproductive senescence. In summary, functional reproductive capacity of male black-footed ferrets exceeds that of females by at least 2 yr. Testes and seminal quality are indistinguishable among males 1 to 5 yr of age, with progressive reproductive aging occurring thereafter.
ISSN:0006-3363
1529-7268
DOI:10.1095/biolreprod63.1.179