Endocrine correlates of female reproductive activity in the roan antelope (Hippotragus equinus)

Although ovarian endocrine activity has been described in most members of the tribe Hippotragini, little is known about the reproductive physiology of the roan antelope (<i>Hippotragus equinus</i>), an endangered antelope species in southern Africa. This study aimed to characterise the endocrine pattern of the oestrous cycle, pregnancy and post-partum period in the species by monitoring faecal progestagen (fPM) and oestrogen metabolite (fEM) concentrations and performing behavioural observations. Eighteen captive females were monitored for 12 months during this study, with individual faecal sampling taking place three times per week during the presumed period of cyclicity, twice per week during pregnancy and daily for 21 days post-partum. The females were observed during mating and calving periods, and courtship events, copulations and births were recorded when noted. Eight of the 18 females monitored showed an oestrous cycle with a distinctive follicular and luteal phase. Patterns of fPM and fEM concentrations indicated an oestrous cycle length of 31.1 ± 1.3 days in multiparous females (n=5), 37 ± 1.4 days in nulliparous females (n=2) and 16.0 days in a primiparous aminal (n=1). The determined length of luteal and follicular phases were 14.0 ± 0.7 days and 16.0 ± 2.4 days in length in multiparous females, 17.1 ± 1.1 days and 16.8 ± 2.2 days in nulliparous females, and 9.0 days and 6.0 days for the primiparous female. Pregnancy was marked by a pronounced increase in fPM concentrations until parturition and lasted approximately 280.4 ± 4.8 days; whereas the intercalving period ranged between 306 and 380 days (mean: 333.2 ± 7.4 days). Twenty-one days after parturition, 78% of the focal females did not show a resumption of the ovarian activity. The present study demonstrated that monitoring faecal reproductive hormone metabolite patterns is a valuable approach for estimating ovarian activity in roan antelope and may be used to assist respective conservation breeding programmes by improving management practices.

尽管马羚族（Hippotragini）多数类群的卵巢内分泌活动已有相关报道，但对于南非濒危羚羊物种马羚（Hippotragus equinus）的繁殖生理，目前仍知之甚少。本研究旨在通过监测粪便孕激素代谢物（fPM）与粪便雌激素代谢物（fEM）浓度，并结合行为观察，对该物种的发情周期、妊娠及产后阶段的内分泌模式进行表征。本研究共监测了18只圈养雌性个体，时长为12个月；其中在推测的发情周期阶段，每周采集3次粪便样本，妊娠期间每周采集2次，产后21天则每日采集1次。研究人员在交配与产犊阶段对雌性个体进行观察，并记录所有可见的求偶行为、交配事件及分娩情况。在监测的18只雌性个体中，有8只呈现出具有典型卵泡期（follicular phase）与黄体期（luteal phase）特征的发情周期。粪便激素代谢物浓度模式显示，经产雌性（multiparous females，n=5）的发情周期时长为31.1±1.3天，未产雌性（nulliparous females，n=2）为37±1.4天，单只初产雌性（primiparous female，n=1）为16.0天。经测定，经产雌性的黄体期与卵泡期时长分别为14.0±0.7天与16.0±2.4天，未产雌性分别为17.1±1.1天与16.8±2.2天，初产雌性则分别为9.0天与6.0天。妊娠以粪便孕激素代谢物浓度显著升高为标志，直至分娩，妊娠时长约为280.4±4.8天；而产仔间隔（intercalving period）为306~380天（平均值为333.2±7.4天）。分娩后21天，78%的目标雌性个体未出现卵巢活动恢复的情况。本研究证实，监测粪便生殖激素代谢物模式可有效评估马羚的卵巢活动，通过优化管理手段，可助力相关保护繁育计划的开展。