Sj, I'm not sure how long PA has been back dating fetuses. I first heard about it at a seminar held by the GC when they were pushing AR. I would think that we need to get 85-90% of the does bred in Oct-Nov instead of the 65-70% where we are at now. I've read that most of the mature bucks will not take part in the later ruts because they are still recovering from the primary rut. Where as the smaller bucks will have more energy and breed the late does.