青年母牛在发情周期中卵泡发育波变化规律的研究

Studies on the Ovarian Follicular Waves in Estrous Cycle of Heifers

为揭示青年母牛卵泡生长发育的动态模式，作者利用B-型超声波诊断仪，对青年母牛在发情周期中卵泡生长发育的过程进行了连续观察。结果表明，卵巢上小卵泡（1～4mm）、中卵泡（5～7mm）和大卵泡（≥8mm）的数量和直径均呈动态变化。大、中、小卵泡的数量、卵泡的发育要经历征集期、选择期、优势化、成熟期和闭锁退化的过程。青年母牛在整个发情周期中，优势卵泡的平均直径为13．6mm，成熟卵泡的平均直径为13．80mm，一个发情周期有3～4个卵泡发育波，其中有3个卵泡发育波的为多数（71．43％），有4个的为28．57％。

The present study was conducted to monitor the process of follicular waves in the estrous cycle heifers using B- Mode ultrasonic scanner, so as to reveal its dynamic developmental pattern. It was shown the quantity and the diameter of small follicles of ovary （diameter： 1 ～ 4 mm） and middle follicles （diameter. 5 ～ 7 mm） and large follicles （over 7 mm diameter） varied greatly. The growth of follicles was undergone with recruitment, and selection, dominance, maturity and the course of recession. The results indicates that the average diameter of dominant follicle and the preovulatory follicles is 13.60 mm, 13.80 mm （13.80±5.30） respectively in whole estrous cycle of heifers, and generally has 1 to 4 follicular waves, in which 3 follicular waves occupy majority （71.43%）, and 4 follicular waves are up to 28. 57%.