Elwisby A B, El Mikkawi F, Omar A A
Beitr Trop Landwirtsch Veterinarmed. 1976;14(3):303-11.
The seasonal variations in sexual desire and semen characteristics were studied in five 1.5 to 2.5 years young and five mature (4 to 5 years old) fat-tailed Ausimi rams. The sexual desire was assessed according to the "reaction time" (period between initiation of the ram and the semen delivery into the artificial vagina): the sperm quality was assessed with the usual parameters. Although the breeding ability of the rams was continuous throughout the year, the sperm density was highest in the summer (due to long daylight periods). On the other hand the sexual desire and semen volumen reached their peak during the autumn. This and other results denote that the complex environmental factors controlling sexual activity exhibit different seasonal effects on different parts of the male reproductive system.
对五只1.5至2.5岁的年轻和五只成熟（4至5岁）的肥尾澳西米公羊的性欲和精液特征的季节性变化进行了研究。根据“反应时间”（公羊开始到精液排入人工阴道的时间段）评估性欲：用常规参数评估精子质量。尽管公羊的繁殖能力全年持续，但精子密度在夏季最高（由于日照时间长）。另一方面，性欲和精液量在秋季达到峰值。这一结果和其他结果表明，控制性行为的复杂环境因素对雄性生殖系统的不同部位表现出不同的季节性影响。
