There is an epidemic in New Zealand of infectious bovine anaemia associated with Theileria orientalis Ikeda type, an obligate intracellular protozoan parasite. To establish whether T. orientalis Ikeda type infection adversely affects fertility of bulls used for natural mating, a randomised controlled experimental study was conducted. Ten of 17 2-year-old Friesian bulls that had not been previously infected with T. orientalis were infected with T. orientalis Ikeda type and then evaluations occurred during a 20-week period. There were semen and libido evaluations every 2 weeks, starting 4 weeks before the date of infection. In addition, there were blood collections, for haematocrit and infection intensity evaluations, rectal temperatures recorded, and bulls weighed three times weekly for 13 weeks after infection and then once weekly until completion of the study. Physical activity meters were also attached from Days 9-60 and 65-124 post-infection. The ten bulls were successfully infected with T. orientalis Ikeda type and this resulted in a decrease in HCT to about 0.25 by 70 days post-infection. There were no effects of infection on semen quality; however, during the acute phase of infection, when the infection intensity was rapidly increasing, the infected bulls took a longer time period for repeated mounting of females, and were less dominant in the herd social heiracrchy. In conclusion, although the transitory effects on libido could reduce conception rates, the overall effects of T. orientalis Ikeda type infection on bull fertility will probably be little.

中文翻译：

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东方泰勒虫池田型感染对公牛性欲和精液质量的影响。

在新西兰，流行性牛贫血的流行与东方泰勒菌池田型有关，后者是专性的细胞内原生动物寄生虫。为了确定T. Orientalis Ikeda型感染是否会对用于自然交配的公牛的生育能力产生不利影响，进行了一项随机对照实验研究。以前未感染过东方锥虫的17岁2岁弗里斯兰公牛中有10只感染了东方锥虫Ikeda型，然后在20周内进行评估。从感染日期前4周开始，每2周进行一次精液和性欲评估。此外，还有血液采集，用于血细胞比容和感染强度评估，记录直肠温度，在感染后的13周内，公牛每周称重3次，然后每周一次称重，直到研究完成。感染后第9-60天和65-124天也要进行体育锻炼。十只公牛成功感染了东方锥虫池田型，这导致感染后70天HCT降低至约0.25。感染对精液质量没有影响。然而，在感染的急性期，当感染强度迅速增加时，被感染的公牛花更长的时间重复繁殖雌性，而在成群的社交杂种中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但是东方锥虫池田型感染对公牛生育力的总体影响可能很小。感染后第9-60天和65-124天也要进行体育锻炼。十只公牛成功感染了东方锥虫池田型，这导致感染后70天HCT降低至约0.25。感染对精液质量没有影响。然而，在感染的急性期，当感染强度迅速增加时，被感染的公牛花更长的时间重复繁殖雌性，而在成群社交杂种中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但东方锥虫池田型感染对公牛生育力的总体影响可能很小。感染后第9-60天和65-124天也要进行体育锻炼。十只公牛成功感染了东方锥虫池田型，这导致感染后70天HCT降低至约0.25。感染对精液质量没有影响；然而，在感染的急性期，当感染强度迅速增加时，被感染的公牛花更长的时间重复繁殖雌性，而在成群的社交杂种中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但是东方锥虫池田型感染对公牛生育力的总体影响可能很小。感染后70天，东方型池田型的HCT降低至约0.25。感染对精液质量没有影响。然而，在感染的急性期，当感染强度迅速增加时，被感染的公牛花更长的时间重复繁殖雌性，而在成群的社交杂种中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但是东方锥虫池田型感染对公牛生育力的总体影响可能很小。Orientalis Ikeda型，这导致感染后70天HCT降低至约0.25。感染对精液质量没有影响。然而，在感染的急性期，当感染强度迅速增加时，被感染的公牛花更长的时间重复繁殖雌性，而在成群的社交杂种中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但是东方锥虫池田型感染对公牛生育力的总体影响可能很小。被感染的公牛花了较长的时间重复繁殖雌性，而在牛群社交活动中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但是东方锥虫池田型感染对公牛生育力的总体影响可能很小。被感染的公牛花了较长的时间重复繁殖雌性，而在牛群社交活动中占主导地位。总之，尽管对性欲的短暂影响可能会降低受孕率，但是东方锥虫池田型感染对公牛生育力的总体影响可能很小。