Relationships between seasonal changes in serum testosterone concentrations, scrotal circumference and sperm morphology of male wapiti (Cervus elaphus)

Abstract

One 2-year-old and 4 adult (> 3 years old) wapiti were studied throughout 1 year. Serum testosterone concentrations, scrotal circumference and % normal spermatozoa in the ejaculate peaked around September. Testosterone levels fell sharply by November, but scrotal circumference declined less sharply and normal sperm production occurred until March. There were indications of a secondary peak in these values around February-March.