Manik R S, Palta P, Singla S K, Sharma V
Embryo Biotechnology Centre, National Dairy Research Institute, Karnal, India.
Reprod Fertil Dev. 2002;14(5-6):315-25. doi: 10.1071/rd01126.
The urgent need for improving the reproductive performance of buffalo necessitates a better understanding of the mechanisms controlling ovarian follicular growth and development. Attention needs to be focused on improving superovulation responses and conception rates, and reducing the variability in ovulation rate and embryo loss. Application of ultrasonic imaging has revealed that follicular turnover during an unstimulated oestrous cycle occurs in waves, with each wave involving synchronous development of a group of follicles, one dominant and several subordinate follicles. There is a predominance of two waves with the first wave beginning around Day 0 (day of ovulation) and the second wave around Day 9 or 10. Primary reasons for a lower superovulation response in buffalo compared with that in cattle is a lower number of primordial and antral follicles, a slower shift from small to large follicles during superovulation, a higher incidence of deep atresia and inability of several large follicles to ovulate, especially when superovulation is induced by equine chorionic gonadotrophin treatment. There is near complete lack of information in Bubalus bubalis on the factors controlling the selection of the dominant follicle, the period of functional dominance and the effects of environmental factors, such as climate and nutrition, on follicular dynamics.
提高水牛繁殖性能的迫切需求使得有必要更好地了解控制卵泡生长和发育的机制。需要将注意力集中在提高超数排卵反应和受孕率，以及减少排卵率和胚胎损失的变异性上。超声成像的应用表明，在未受刺激的发情周期中，卵泡更替呈波状发生，每一波都涉及一组卵泡的同步发育，其中有一个优势卵泡和几个从属卵泡。主要有两波，第一波大约在第0天（排卵日）开始，第二波大约在第9天或第10天。与牛相比，水牛超数排卵反应较低的主要原因是原始卵泡和有腔卵泡数量较少，超数排卵期间从小卵泡向大卵泡的转变较慢，深度闭锁的发生率较高，以及几个大卵泡无法排卵，特别是在用人绒毛膜促性腺激素治疗诱导超数排卵时。关于控制水牛优势卵泡选择的因素、功能优势期以及气候和营养等环境因素对卵泡动态的影响，几乎完全缺乏相关信息。
