Relationship between serum testosterone concentrations and fertility in male mink (Mustela vison)

During 7 successive months in 1982 and 1983 blood and semen samples were taken from male mink. The patterns of testosterone development in sterile and fertile males were readily distinguishable from each other. Testosterone concentrations showed a clear correlation (r = 0.73) with sperm quality of mink males. High testosterone levels (16.0-24.5 ng/ml) in early February were associated with defective sperm quality in March and low testosterone levels (2.0-13.3 ng/ml) with good sperm quality.