Three insert treatments were used for this experiment: (1) new, (2) re-used disinfected (DIS),
and (3) re-used autoclaved (AC). All CIDR inserts to be re-used had been obtained from cows
involved in a previous synchronization of ovulation experiment, and had been inserted initially
for 7 days. Immediately after removal, they were placed in an empty bucket, washed
thoroughly with soap and water, with emphasis on trying to remove mucus and debris that
had accumulated in empty spaces between the silicon layer and the T-shaped body. Inserts for
the DIS treatment were soaked in a chlorhexidine gluconate solution (0.03%) for 2 h, rinsed
thoroughly with water, allowed to air-dry and placed in zip-lock bags for storage. For the
AC treatment, CIDR inserts were not soaked in disinfectant but were autoclaved at 121 ◦C
and 724mmHg for 20 min, allowed to cool and placed in zip-lock bags for storage before
use.