A total of 28 weekly replicates were completed. For
21 replicates, cows were randomly assigned to one of three
treatment groups: (1) TAI with nonsorted semen; (2) TET
with a fresh embryo produced using nonsorted sperm; and
(3) TET with a fresh embryo produced using X-sorted sperm.
For seven replicates, a fourth treatment group, TET with
a vitrified embryo produced using X-sorted sperm, was also
included. At Farm 1, cows that were assigned to the TAI
group were inseminated on Day 0 in conjunction with the
second GnRH treatment of the Ovsynch protocol. At Farms 2
and 3, cows assigned to the TAI group were inseminated on
Day 0, 16 hours after the second GnRH treatment of the
Ovsynch protocol. Of 100 inseminated cows, 87 were
inseminated using semen from one of the bulls used to
produce embryos and 13 were inseminated with semen
from one of five bulls not used for embryo production.