I've used sexed semen on a small scale (I have a small herd) with pretty good success over the years, though I have not used it much the past couple of years because of the lack of availability through most of the major stud companies. I used to use sexed semen acquired through Genex when a number of their bulls had sexed semen available (Right Answer, Bismarck, Thunder, Density to name a few). One year I had an 80 percent conception rate and most years my conception rate was as good or better than conventional semen conception rates. -- 65 percent or so. I only used sexed semen with natural heat detection, not timed AI or synced protocols. I just discovered ST Genetics late last year and have been studying their 2017 spring semen catalog pretty regularly and it appears they have some nice young bulls in their lineup, though a lot of them are young and unproven. I likely will order a few straws and see what happens.