Abstract：
In cheetahs, age at first parturition correlates negatively with reproductive lifespan (asymmetric reproductive aging); therefore, breeding cheetahs at a young age is essential to maximize reproductive performance in this species. However, younger females display a significantly reduced frequency of copulatory behaviour, which negatively affects breeding. Volatile organic compounds (VOCs) are known to regulate appropriate behavioural responses in various species, including reproductive behaviour; moreover, they have proven to play a role in captive breeding methods in cheetahs, as well as mate choice. Therefore, the objective of this study was to evaluate the effect of a synthetic scent (SS) on the frequency of the five oestrous behaviour(s) (sniff, rub, roll, spray, and meow-chirp) known to be indicative of oestrus in female cheetahs. Based on the results of a previous study from our research group, five VOCs, identified in the marking fluid of male cheetahs, and known to be pheromones involved in reproductive behaviour, were used to create the SS. This was accomplished by mixing benzaldehyde, acetophenone, indole, dimethyl disulphide and phenol with (99.9%) ethanol. Seven female cheetahs were then observed for one oestrus cycle without stimulation (control) and then once again while exposed to the SS (treatment), which was sprayed on foil trays placed around the outside of each enclosure. The occurrence of the five oestrous behaviours was recorded and tallied per day of observations. Although the SS did not have a significant effect on the frequency of oestrous behaviours displayed by the females used in this study, five of the seven (71%) did show an increase in their behaviour with the SS when oestrogen concentrations were at their highest (peak oestrus), including three of the four younger females. The SS also significantly increased the sniffing behaviour in general. Although the results of this study do indicate that VOCs influence cheetahs and their behaviour, firm conclusions cannot be drawn due to the low number of animals used, as well as the significant effect the observation methods had on the results. Nonetheless, this study represents the first of this kind in cheetahs, therefore representing an important step in determining the role of VOCs in aiding breeding in captivity.
摘要：
在猎豹里,初产年龄与生殖寿命(不对称生殖衰老)呈负相关；因此，在幼年繁殖猎豹对于最大程度地提高该物种的繁殖性能至关重要。然而,年轻女性表现出明显减少的交配行为频率，这对育种产生了负面影响。已知挥发性有机化合物（VOC）可以调节各种物种的适当行为反应，包括生殖行为；此外，它们已经证明在猎豹的圈养繁殖方法中发挥作用，以及伴侣的选择。因此,本研究的目的是评估合成气味（SS）对五种发情行为频率的影响（嗅闻，rub,roll,喷雾,和喵喵叫）已知是雌性猎豹发情的指示。根据我们研究小组先前的研究结果，五种挥发性有机化合物，在雄性猎豹的标记液中识别，已知是与生殖行为有关的信息素，用于创建SS。这是通过混合苯甲醛来实现的，苯乙酮,吲哚,二甲基二硫化物和苯酚与（99.9％）乙醇。然后观察七只雌性猎豹一个发情周期，没有刺激（对照），然后再次暴露于SS（治疗），将其喷涂在围绕每个外壳外部放置的箔托盘上。每天观察记录并统计五种发情行为的发生。尽管SS对本研究中使用的女性表现出的发情行为的频率没有显着影响，当雌激素浓度达到最高（发情高峰）时，七个中的五个（71％）确实显示出与SS的行为增加，包括四名年轻女性中的三名。SS总体上也显著增加了嗅探行为。尽管这项研究的结果确实表明挥发性有机化合物会影响猎豹及其行为，由于使用的动物数量少，无法得出确切的结论，以及观察方法对结果的显著影响。尽管如此，这项研究代表了猎豹中的第一个，因此，这是确定VOCs在圈养繁殖中的作用的重要一步。
