ウシ伸長期胚の非外科的移植技術

　The objectives of the present study were to establish a non-surgical transfer method for elongating bovine conceptuses and to combine this method with biopsy and sexing. Bovine conceptuses were recovered from donor cows on day 13-14 of the estrus cycle. In experiment 1, day 13 conceptuses were transferred to recipient cows using a standard day 7 embryo transfer (ET) method. The pregnancy rate of day 13 conceptus transfer (CT) is comparable to that of day 7 ET. In experiment 2, day 14 conceptuses were transferred using modified methods (balloon catheters or ET guns with modified sheaths). Using the standard ET method, no pregnancies were obtained;however, when balloon catheters or ET guns with modified sheaths were used, the pregnancy rates after CT were 48.0％ and 44.8％, respectively. In experiment 3, day 14 conceptuses were biopsied without a micromanipulator, sexed using the loop-mediated isothermal amplification (LAMP) method, and transferred to recipient cows. The pregnancy rate of biopsied conceptuses was 46.2％ and did not differ significantly from that of unbiopsied with conceptuses. Moreover, all pregnant cows transferred conceptuses following biopsy and sexing delivered calves with the expected sexes. These results suggested that the non-surgical bovine conceptus transfer (CT) method was comparable to day 7 ET, and that this technique enables biopsy and sexing without expensive equipment such as a micromanipulator or specialized skills.

研究紹介 (Research Report)