Sorting effects of X/Y sperm on in vitro fertilization of Belgian blue bulls

There is a large market in China for the production of Belgian blue bulls, which would benefit from semen flow sorting for animal sex control. The sperms of the Belgian blue bulls were separated by flow cytometry, and then the quality of sorted sperm was tested by in vitro fertilization (IVF) and artificial insemination (AI). The fresh semen of 8 Belgian blue bulls was individually collected and processed for sorting. Sperm sorting was carried out using MOFLO cell sorter and cryopreservation. There were no significant differences in sperm motility, acrosome integrity, and DNA integrity between sex-sorted and non-sorted sperm (p > 0.05). The purified sperm with higher viability was fertilized with mature oocytes in vitro, co-cultured to cleavage and blastocyst stage, embryo sex was identified by nested PCR amplification of AMEL gene, and there was no significant difference between sorted sperm and non-sorted sperm (p > 0.05). For artificial insemination, the pregnancy rate using non-sorted sperm was higher than for sorted sperm (p < 0.05). After delivery, the sex ratio of offspring using X- and Y-sperm was 100% and 90.9%, respectively, with a significant deviation from conventional semen (p < 0.05). The birth weight of male and female calves in the control group was similar to that in the sex-sorted sperm (p > 0.05). In summary, after artificial insemination using sex-sorted sperm, normal Belgian blue calves with the predicted gender can be produced. It is of great significance to improve the commercial promotion and production efficiency of semen after sorting Belgian blue bulls.