Hey Norma -- I may have gotten too windy in my long post above, but I absolutely infuse EVERY donor after the flush before she leaves, I leave no chances of a pregnancy and it cleans up anything that may have been caused by the flush.
I don't agree with shooting them, but I absolutely do agree that we must make sure she is not carrying a stray embryo we missed (Yes, even I can miss one - it can happen). Infusing them with Bio-Mycin, buffered for the uterus - will insure no eggs survive, and also she is clean to go forward.
Sorry if you misunderstood. I just don't like to ask them to recycle a few days after the flush, mine will take two weeks - which will usually be a day plus/minus from a normal 21 day day heat from flush heat. Very seldom do I see a cow go more than a few days past her normal 21, this simply works with very little afects later. We haven't had a cow go cystic in so long I can't remember, and that may be the real reason I do not shoot them.
Which ever way works for every one I guess -- but this works for me and I have no regrets. I think the main reason most of the vets are giving PgF is to not get a call from a mad producer, but it can cause problems with some of these fertile cows. Cysts are not fun to deal with, so I don't take that chance.
Good luck to all -- sorry so windy
Terry