Sasamoto Yoshihiko, Sakaguchi Minoru, Nagano Masashi, Katagiri Seiji, Takahashi Yoshiyuki
Laboratory of Theriogenology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Jpn J Vet Res. 2004 Feb;51(3-4):151-9.
This study aimed to evaluate gonadotropin secretion and the developmental competence of follicular oocytes in dairy cattle during the early postpartum (PP) period. The number of follicles developed after transvaginal ultrasound-guided ovum pick-up (OPU) and fertilizability of retrieved oocytes were compared between cows in which the first dominant follicle (DF) ovulated (ovulated group, n=4) and did not ovulate (non-ovulated group, n=3), and between early PP (early PP group, n=2) and after the resumption of the estrous cycle (cyclic group, n=2). Follicular ablation was performed 2-4 days after the detection of DF in the second follicular wave PP. OPU was repeated 3-5 times at 3 or 4-day intervals from 3-4 days after the follicular ablation. At OPU, the follicles were enumerated and all those > or = 5 mm in diameter were aspirated. Recovered oocytes were subjected to in vitro maturation and fertilization. Both criteria were similar between ovulated and non-ovulated groups, and between early PP and cyclic groups. These results suggest that FSH/LH secretions required for follicle recruitment and subsequent follicular growth during the early PP period are similar to those after resumption of the estrous cycle. They also indicate that follicular oocytes during the early PP period have developmental competence.
本研究旨在评估奶牛产后早期（PP）促性腺激素的分泌情况以及卵泡卵母细胞的发育能力。比较经阴道超声引导下采卵（OPU）后发育的卵泡数量以及回收卵母细胞的受精能力，比较对象为首次优势卵泡（DF）排卵的奶牛（排卵组，n = 4）和未排卵的奶牛（未排卵组，n = 3），以及产后早期（产后早期组，n = 2）和发情周期恢复后（周期组，n = 2）的奶牛。在产后第二个卵泡波中检测到DF后2 - 4天进行卵泡消融。卵泡消融后3 - 4天开始，每隔3或4天重复OPU 3 - 5次。在OPU时，对卵泡进行计数，抽吸所有直径≥5 mm的卵泡。回收的卵母细胞进行体外成熟和受精。排卵组和未排卵组之间以及产后早期组和周期组之间的这两个标准相似。这些结果表明，产后早期卵泡募集和随后卵泡生长所需的促卵泡生成素/促黄体生成素分泌与发情周期恢复后的分泌情况相似。它们还表明，产后早期的卵泡卵母细胞具有发育能力。
