One cow in the 5CO treatment was removed during the
project because of inflammation in the rectum. The proportion
of cows that were cyclic at initiation of treatment,
and the proportion that responded to GnRH-1 did not differ
between treatments (Table 1). In the five cows that failed to
respond to GnRH-1 in the 5CO treatment, emergence was
classified as pre-GnRH-1 in three cows, at GnRH-1 in one
cow, and post-GnRH-1 in one cow. In the four cows that
failed to respond to GnRH-1 in the 7CO treatment, none
had follicular emergence before GnRH-1, one cow had
emergence at GnRH-1, and three cows had emergence after
GnRH-1. One cow in the 7CO treatment developed a cystic
follicle that did not ovulate after GnRH-2 administration;
whereas two cows in the 7CO treatment ovulated but failed
to develop a functional CL. In the 5CO treatment, a single
cow spontaneously ovulated between hours 60 and 72,
whereas all remaining cows ovulated after GnRH-2;
including one cow that ovulated two follicles.