Cows that exhibited estrus had a greater pregnancy rate
compared with cows that did not. It is interesting to note
that more cows in the 7-day CO-Synch þ CIDR group
exhibited estrus compared with cows in the 5-day COSynch
þ CIDR group; nevertheless, a greater proportion
of cows in the 5-day CO-Synch þ CIDR group became
pregnant. There was no treatment by estrus expression
interaction for AI pregnancy rate (P > 0.1). Location greatly
influenced AI pregnancy rate (P < 0.0001), which may have
been a result of differing management, nutrition, genetics,
production goals, and environment.