Bitches have their first estrus ( also know as season or heat ) after six months of age , although it can occur as late as 18 months to two years of age 一些在母犬六个月龄后就会有第一次发情，有些则会迟至18个月甚至两岁。
Progesterone levels remain elevated for 8 to 10 weeks following estrus in order to thicken the lining of the uterus in preparation for pregnancy 黄体酮的水平会在发情期之后的八到十周内持续增高，以加厚子宫内膜，从而为怀孕做准备。
It significantly enhances mature follicle ovulation and induces luteum to continue production in female animals . it can stimulate female animals into estrus 本品可促进雌性动物成熟卵泡排卵和黄体生成，延缓黄体的存在；并能刺激卵巢分泌雌激素而引起发情。
The staff from mianning county said , after the good care from their staff , it is not in dangerous now , eat food , drink , and suppose to get estrus 据来自冕宁的管理人员介绍，该猫经悉心照料，已经脱离生命危险，身体状况较好，能正常进食、喝水、排便，可能有发情迹象。
Action and use it significantly enhances mature follicle ovulation and induces luteum to continue production in female animals . it can stimulate female animals into estrus 本品可促进雌性动物成熟卵泡排卵和黄体生成，延缓黄体的存在；并能刺激卵巢分泌雌激素而引起发情。
Recently , giant panda jin zhu got estrus , and very bad fighting with other male pandas , her ear got hurt , with the treatment from the staff , it has already healed 前段时间大熊猫锦竹发情期间因为自身特殊原因，与种公猫相互打架，导致耳朵很受伤。经过科研人员的精心治疗，现在耳朵已经痊愈。
The disease , low quality of embryo , semen contamination , breeding out of time , low quality of recipient , not synchronous estrus between donor and recipient , antiquated preserve to embryo , hereditary unsoundness , accidental injury by medicament , vaccination , feeding and management to depart from science , immunological reaction and multiple embryo in uterus are the more important factors 这些因子主要包括疾病、胚胎质量差、精液污染、不适时配种、受体羊质量差、供受体羊发情不同步、胚胎保存时间长、遗传缺陷、误用药物、接种疫苗、饲管不科学、免疫反应、子宫内多胚等。
In the present study , in order to investigate the effects of endogenous estrogen on the daergic terminals in amy and the daergic neurons in midbrain , fast cyclic voltammetry ( fcv ) was used to examine da release evoked by electrical stimulation from amy of female rats in different phases of estrus cycle , ovx rats and male rats . and tyrosine hydroxylase ( th ) immunohistochemi stry was employed to measure the numbers of daergic neurons of ventral tegmental area ( vta ) and substantia nigra ( snc ) in the rats 因此，为进一步探讨大鼠内源性雌激素水平的变化对amyda能神经系统及中脑da能神经元的影响，本工作应用快速周期伏安法( fcv )在体监测了处于动情周期各期雌鼠、 ovx鼠和雄鼠经电刺激诱发的amyda释放，并应用酪氨酸羟化酶( th )免疫组化方法测定了以上各组大鼠腹侧背盖区( vta ) 、黑质( snc )的th阳性神经元数目。
Amy da release of proestrus female rats was apparently higher than estrus , metestrus and ciestrus female rats , but no significant difference was observed among estrus , metestrus and ciestrus female rats . da release in ovx rats was higher compared with male rats , but lower than proestrus female rats . no difference appeared among ovx rats and estrus , moiestrus , ciestrus female rats 电刺激vta诱发的雄鼠amyda释放量明显低于雌鼠和ovx鼠；处于动情前期雌鼠的amyda释放量高于动情期、动情后期和动中文摘要情间期雌鼠；而动情期、后期及间期雌鼠间da释放量差异无统计学意义； ovx鼠da释放量高于雄鼠，低于动倩前期雌鼠，但与动情期、后期及间期雌鼠比较无显著差异。
