Although donkeys have been domesticated for over 6,000 years, limited information is available concerning their reproductive physiology, especially under intensive rearing conditions. The aims of this experiment were to study follicular dynamics and reproductive hormone variation in jennies during the inter‐ovulatory interval in different seasons. A total of 12 continuous cycles of six Dezhou Black (DB) donkey jennies were examined in four different seasons. The diameters of the six largest follicles of each jenny were measured daily by ultrasonography, and blood samples were collected at fixed times for reproductive hormone assays. The results demonstrated that most jennies displayed regular oestrous cycles in all seasons. The follicular dynamics were similar in Spring, Summer and Winter, while the jennies had longer oestrous cycles with delayed follicular deviation and dominant selection in Autumn. At least two follicular waves were observed in each oestrous cycle, throughout the study, but two jennies presented oestrous cycles with three follicular waves in the Autumn. The numbers of follicular waves were consistent with the numbers of FSH surges. Oestrous characteristics of the jennies in a large herd were also analysed. The results showed that the rates of regular oestrous cycles were 83.1% (265/319), 89.6% (215/240), 80.2% (235/293) and 77.1% (178/231), with 26.4% (70/265), 19.5% (42/215), 22.1% (52/235) and 23.0% (41/178) double ovulation rates in Spring, Summer, Autumn and Winter, respectively. The results presented may be useful for donkey farms in the design of breeding strategies.

中文翻译：

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一整年珍妮的发情周期中卵泡动力学和生殖激素谱的特征

尽管驴已经被驯化了 6,000 多年，但有关其生殖生理学的信息有限，尤其是在集约化饲养条件下。本实验的目的是研究不同季节排卵间隔期间珍妮的卵泡动力学和生殖激素变化。在四个不同的季节，总共对 6 头德州黑 (DB) 驴珍妮的 12 个连续循环进行了检查。每天通过超声检查每个珍妮的六个最大卵泡的直径，并在固定时间收集血液样本用于生殖激素测定。结果表明，大多数珍妮猫在所有季节都表现出规律的发情周期。春季、夏季和冬季的卵泡动力学相似，而珍妮的发情周期更长，卵泡偏差延迟，秋季优势选择。在整个研究过程中，在每个发情周期中至少观察到两个卵泡波，但在秋季，两个 jennie 出现了三个卵泡波的发情周期。卵泡波数与 FSH 激增数一致。还分析了一大群珍妮的发情特征。结果表明，有规律的发情周期率为83.1%（265/319）、89.6%（215/240）、80.2%（235/293）和77.1%（178/231），26.4%（70/265） )、春季、夏季、秋季和冬季的双排卵率分别为 19.5% (42/215)、22.1% (52/235) 和 23.0% (41/178)。所呈现的结果可能对驴场设计育种策略有用。