Effect of sex-sorted sperm on development and quality of in vitro-produced bovine embryos derived from ovum pick up oocytes.

摘要

A combination of sex-sorted sperm and ovum pick up (OPU)-in vitro fertilization (IVF) techniques could improve the overall efficiency of the process and develop the commercial opportunities for sexsorted sperm. Despite intrinsic differences which have been found between bovine oocytes collected post-mortem from slaughterhouse ovaries and those collected by OPU, only a few studies about IVF with sex-sorted sperm have used oocytes collected by OPU. In addition, to our knowledge, the effect of sex-sorted sperm on embryo development and quality using OPU-oocytes have been studied in buffalo (Bubalus bubalis) and in Bos indicus, but not in Bos taurus, therefore we aim to address this issue in this study. Oocytes were retrieved by OPU from mature dry cows and in vitro matured. In vitro fertilization was performed with sex-sorted or unsorted sperm, and afterwards presumptive zygotes were in vitro cultured for 9 days. Oocytes fertilized with sex-sorted sperm showed a lower cleavage rate (52.43 vs. 69.09%, respectively; P<0.05) but similar blastocyst rate compared to oocytes fertilized by unsorted sperm (29.63 vs. 31.58%, respectively). Moreover, the percentages of excellent or good blastocyst (87.50 vs. 85.71%) as well as the timing of the blastocyst formation at day 7 (10.53 vs. 5.56%) and day 8 (30.26 vs. 24.07%) post IVF was not different between sex-sorted and unsorted groups. In conclusion, sex-sorted sperm and OPU-IVF are efficient and valuable tools to produce bovine embryos of predetermined sex and from individual donors.