Semen collection using electroejaculation and sperm parameters in pacas (Cuniculus paca, Linnaeus, 1766)

ABSTRACT Pacas (Cuniculus paca) are highly hunted animals because of the flavor of their meat, and commercial breeding is recommended. However, this species has a relatively low reproductive rate. This study aimed to collect semen from pacas through electroejaculation and obtain the sperm parameters of this species for the first time. Seven male pacas were used, submitted to an anesthetic protocol before stimulation by an electroejaculator appropriate for the species. The stimulus protocol was performed in three series: series I, 10 stimuli with 1 and 2 V; series II, 10 stimuli with 3 and 4 V; and series III, 10 stimuli with 5 V and interval between series of 2 s. The collected material was evaluated for color, volume, motility, vigor, and concentration. The sperm parameters collected showed a mean volume of 0.43±0.33 mL, concentration of 45.5±42.44×106 sperm/mL, motility of 33.33±32.14%, and mean vigor of 2.6±1.15. In this study, the anesthetic protocol did not seem to favor semen collection by electroejaculation in the pacas. The electrical stimulation protocol was able to stimulate all animals in the study; however, there were few samples with sperm cells and a low rate of motility and vigor in most ejaculates.

摘要
斑豚鼠（Cuniculus paca）因肉质鲜美而遭到大量捕猎，因此推荐开展商业化养殖。然而该物种的繁殖率相对较低。本研究首次尝试通过电刺激采精法（electroejaculation）采集斑豚鼠的精液，并获取该物种的精子参数。本次研究选用7只雄性斑豚鼠，在使用适配该物种的电刺激采精仪（electroejaculator）进行刺激前，先对受试个体实施麻醉方案。刺激方案分为三个阶段：第一阶段以1V与2V电压进行10次刺激；第二阶段以3V与4V电压进行10次刺激；第三阶段以5V电压进行10次刺激，且各阶段间隔2秒。对采集得到的样本开展色泽、体积、精子活力、运动等级及浓度的检测。本次采集的精子参数结果显示：平均精液体积为0.43±0.33 mL，精子浓度为45.5±42.44×10^6 个/mL，精子活力为33.33±32.14%，平均运动等级为2.6±1.15。本研究结果表明，所采用的麻醉方案似乎不利于斑豚鼠的电刺激采精操作。尽管本次电刺激方案可成功激活所有受试动物，但多数射精样本中可获取的精子数量极少，且大部分精液样本的精子活力与运动等级均处于较低水平。