There are quite a few things in that protocol that do not fit with bovine endocrinology. 1) Without keeping the CIDR in for 7 days, you are not giving all of the cows a chance to form a CL. 2) The 2 shots of PGF2a within 8 hrs is redundant and the second shot should have no affect. 3) If a particular cow was receptive to this protocol, I would still expect her to be in heat within 48 hrs of pulling the CIDR, which means that if you breed at 72 hrs, you missed her.