Machatkova M, Jokesova E, Horky F, Krepelova A
Research and Developmental Center of the Czech and Moravian Breeders' Association Prague.
Theriogenology. 2000 Sep 1;54(4):543-50. doi: 10.1016/S0093-691X(00)00369-1.
Characteristics of the follicle population and oocyte developmental competence at selected stages of follicular development were studied in cows with the aim to increase embryo production derived from oocytes collected by transvaginal aspiration. In Experiment 1, the growth phase before dominant follicle selection and the low dominant phase during dominant follicle regression were compared. Twenty-four cyclic Holstein cows, 4 to 6 yr of age, were divided into 2 groups. Animals were synchronized using two injections of prostaglandin F2alpha at 11 d intervals, and onset of estrus was determined (Day 0). Using ultrasonography, all follicles were counted and classified. Oocytes were aspirated once on Days I through 3 (Group 1, n=5) or Days 15 and 16 (Group 2, n=3) of the estrus cycle. The experiment was carried out in 3 replicates. In Experiment 2, the growth phase of the first follicular wave before dominant follicle selection was characterized in detail. Twelve cows of the same breed and age were divided into 3 groups. Their first estrus was synchronized as in Experiment 1, and each following estrus was induced using one injection of prostaglandin F2alpha administered 4 to 6 d after each aspiration performed. The ovaries were examined, and oocytes were collected repeatedly (total of 5 times per cow) on Days 1 (Group 3, n=4), 2 (Group 4, n=4) or 3 (Group 5, n=4) after estrus at 10 d intervals during a 40 d period. Viable oocytes were matured, fertilized and cultured using the standard methods. In Experiment 1, the mean numbers (+/-SD) of all follicles and of recovered and viable oocytes per donor were higher in Group 1 than in Group 2, but only the mean numbers (+/-SD) of larger follicles and recovered oocytes were statistically significant (8.0 +/- 0.6 and 6.2 +/- 0.6.vs. 3.3 +/- 0.5 and 2.8 +/- 0.2; P< 0.05). In Experiment 2, the percentage of larger follicles out of all visible follicles and the mean numbers (+/-SD) of larger follicles per donor were significantly higher (P<0.05) in Groups 4 (75.7 and 9.1 +/- 2.7) and 5 (66.3 and 8.5 +/- 2.9) when compared to Group 3 (27.9 and 3.8 +/- 0.8). The development rate of fertilized oocytes was significantly higher (P<0.05) in Groups 4 (27.8) and 5 (27.5) than in Group 3 (12.8). It can be concluded that it is possible to improve the efficiency of transvaginal aspiration and in vitro embryo production by utilization of the growth phase of the first follicular wave before dominant follicle selection.
为提高经阴道抽吸采集的卵母细胞的胚胎生产效率，对母牛卵泡发育选定阶段的卵泡群体特征和卵母细胞发育能力进行了研究。在实验1中，比较了优势卵泡选择前的生长阶段和优势卵泡退化期间的低优势阶段。将24头4至6岁的周期性荷斯坦奶牛分为2组。每隔11天使用两次前列腺素F2α注射使动物同期发情，并确定发情开始时间（第0天）。使用超声检查对所有卵泡进行计数和分类。在发情周期的第1至3天（第1组，n = 5）或第15和16天（第2组，n = 3）对卵母细胞进行一次抽吸。该实验进行了3次重复。在实验2中，详细描述了优势卵泡选择前第一个卵泡波的生长阶段。将12头相同品种和年龄的奶牛分为3组。它们的第一次发情与实验1中一样进行同期发情处理，每次抽吸后4至6天使用一次前列腺素F2α注射诱导每次随后的发情。检查卵巢，并在40天期间每隔10天在发情后第1天（第3组，n = 4）、第2天（第4组，n = 4）或第3天（第5组，n = 4）对每头奶牛重复收集卵母细胞（每头奶牛总共5次）。使用标准方法使有活力卵母细胞成熟、受精并培养。在实验1中，第1组每个供体的所有卵泡、回收的和有活力卵母细胞的平均数（±标准差）高于第2组，但只有较大卵泡和回收卵母细胞的平均数（±标准差）具有统计学意义（8.0±0.6和6.2±0.6对3.3±0.5和2.8±0.2；P<0.05）。在实验2中，与第3组（27.9和3.8±0.8）相比，第4组（75.7和9.1±2.7）和第5组（66.3和8.5±2.9）中所有可见卵泡中较大卵泡的百分比和每个供体较大卵泡的平均数（±标准差）显著更高（P<0.05）。第4组（27.8）和第5组（27.5）中受精卵母细胞的发育率显著高于第3组（12.8）（P<0.05）。可以得出结论，通过利用优势卵泡选择前第一个卵泡波的生长阶段，可以提高经阴道抽吸和体外胚胎生产的效率。
