Loy R G, Hughes J P, Richards W P, Swan S M
J Reprod Fertil Suppl. 1975 Oct(23):291-5.
The injection of 100 mg of progesterone/day from Days 5 to 14 after foaling blocked or delayed oestrus and ovulation in 6/9 mares; the remainder ovulated during treatment without showing oestrus. Urinary oestrogen concentrations in these mares were highest between Days 9 and 15 after foaling but the peak levels were only about half those seen in untreated mares during the post-partum oestrus and ovulation. The injection of 200 mg progesterone/day blocked oestrus and ovulation in two mares but did not depress oestrogen excretion maxima any further. Follicles prevented from developing beyond a cricital stage lost their ability to ovulate after progesterone withdrawal. No significant histological differences were found in endometrial biopsies taken from progesterone-treated and control mares on Days 5, 10 and 15 after foaling. Injection of 100 mg progesterone between Days 1 and 10 after foaling delayed oestrus and ovulation in all six mares. Conception occurred in 8/12 progesterone-treated mares as the result of mating at oestrous periods which were delayed until Days 15 to 28 after foaling.
产后第5天至第14天每天注射100毫克孕酮，9匹母马中有6匹发情和排卵被阻断或延迟；其余母马在治疗期间排卵但未表现出发情。这些母马的尿雌激素浓度在产后第9天至第15天之间最高，但峰值水平仅约为未治疗母马在产后发情和排卵期间所见峰值的一半。每天注射200毫克孕酮使两匹母马的发情和排卵受到阻断，但并未进一步降低雌激素排泄最大值。在关键阶段之后发育受阻的卵泡在孕酮撤药后失去排卵能力。产后第5天、第10天和第15天从接受孕酮治疗的母马和对照母马获取的子宫内膜活检标本未发现明显的组织学差异。产后第1天至第10天注射100毫克孕酮使所有6匹母马的发情和排卵延迟。12匹接受孕酮治疗的母马中有8匹在发情期交配受孕，发情期延迟至产后第15天至第28天。
