2.2.3. AI and ET
Cows were located at two commercial dairy farms in
Colorado. Cows were assigned randomly within week to
one of four treatments as follows: (1) timed AI (TAI) with
nonsorted semen (control); (2) TAI with X-sorted sperm;
(3) timed ET (TET) with an embryo produced with nonsorted
sperm; (4) and TET of an embryo produced with
X-sorted sperm. Semen for cows bred by AI were from the
same bulls as used to produce embryos. All three bulls
(Dairy 1) or two bulls (Dairy 2) were used for AI each week.
All embryos were transferred fresh.