Westlin-van Aarde L M, van Aarde R J, Skinner J D
Mammal Research Institute, University of Pretoria, South Africa.
J Reprod Fertil. 1988 Nov;84(2):505-11. doi: 10.1530/jrf.0.0840505.
Ovaries, fetuses and plasma were collected from zebra mares shot in the Etosha National Park in Namibia between 15 and 25 August 1983. Ovarian weight was affected by reproductive status and most of the non-pregnant mares were anoestrous. The number of follicles varied between individuals and only pro-oestrous/oestrous mares had follicles larger than 20 mm in diameter. The largest follicle in pregnant mares was only 9 mm in diameter. Corpora lutea and corpora albicantia were found in non-pregnant as well as pregnant mares: 4 pregnant mares had only corpora albicantia. The presence of secondary corpora lutea could not be confirmed in any of the pregnant mares. Implantation was estimated to occur at around 73 days of gestation, and most mares (84%) had conceived between November and April. Peripheral concentrations of plasma progesterone during pregnancy varied from 0.5 to 2.4 ng/ml.
1983年8月15日至25日期间，从纳米比亚埃托沙国家公园射杀的斑马母马身上采集了卵巢、胎儿和血浆。卵巢重量受生殖状态影响，大多数未怀孕的母马处于发情间期。卵泡数量因个体而异，只有发情前期/发情期的母马有直径大于20毫米的卵泡。怀孕母马中最大的卵泡直径仅9毫米。在未怀孕和怀孕的母马中均发现了黄体和白体：4匹怀孕母马只有白体。在任何一匹怀孕母马中均未证实有继发性黄体存在。据估计，着床发生在妊娠约73天时，大多数母马（84%）在11月至4月期间受孕。怀孕期间血浆孕酮的外周浓度在0.5至2.4纳克/毫升之间变化。
