Sekoni V O
National Animal Production Research Institute, Ahmadu Bello University, Shika-Zaria, Nigeria.
Br Vet J. 1992 Nov-Dec;148(6):501-6. doi: 10.1016/0007-1935(92)90005-L.
Twelve Yankasa rams aged between 2 1/2 and 3 years with good semen characteristics were used in this 15-week study. Six rams were infected with Trypanosoma vivax, while six served as controls. The infected rams developed chronic trypanosomosis accompanied by fluctuating pyrexia, lethargy, anaemia, scrotal oedema and cachexia. There was a drastic and progressive deterioration in semen quality in all infected rams manifested by a decrease in volume or cessation of semen production, oligozoospermia, a sharp decrease in progressively motile sperm, elevated numbers of dead (eosinophilic) sperm and 100% morphological abnormalities of sperm in most animals. The rams were all deemed unfit for breeding by 3 weeks post-infection. Uninfected rams were healthy and had good semen characteristics throughout the investigation. The results show that rams infected with T. vivax may become infertile within a short interval due to rapid deterioration of semen characteristics and this trypanosome species may be an important causative agent of infertility in endemic areas.
在这项为期15周的研究中，选用了12只年龄在2.5至3岁之间、精液特征良好的扬卡萨公羊。6只公羊感染了活泼锥虫，另外6只作为对照。受感染的公羊患上了慢性锥虫病，伴有体温波动、嗜睡、贫血、阴囊水肿和恶病质。所有受感染公羊的精液质量都急剧且持续恶化，表现为精液量减少或停止产生、少精子症、进行性运动精子数量急剧下降、死亡（嗜酸性）精子数量增加，且大多数动物的精子形态异常率达100%。感染后3周，所有公羊都被认为不适于繁殖。在整个调查过程中，未感染的公羊健康且精液特征良好。结果表明，感染活泼锥虫的公羊可能会因精液特征迅速恶化而在短时间内不育，这种锥虫物种可能是流行地区不育症的重要病因。
