Perhaps embryos derived from X-sorted sperm would
have lower competence to establish pregnancy after
transfer to a recipient, because of sperm damage caused
during the sorting process. Indeed, there was evidence in
both Colorado and Florida studies for damage to X-sorted
sperm as indicated by reduced development of fertilized
oocytes to the blastocyst stage. Overall, however, there was
no difference in competency to establish pregnancies for
embryos produced with X-sorted sperm as compared with
those produced using nonsorted semen. Similarly, Xu et al.
[7] reported no decrease in calving rates with embryos
from sexed sperm compared with controls.