I have never flushed a heifer, and probably won't as I just prefer to have some knowledge of their productivity prior to doing the flush. I may consider it if it was a very exceptional heifer that became injured, but I prefer not too. That is not to say, that virgin flushes cannot be successful. I know of many that have proven very successful with no visible adverse effects to the heifer. I just don't prefer to do it.( and that is not based on any science etc).I have heard so some heifers that have had trouble breeding aftr being flushed and I have heard the same on some cows. I doubt if this is much of an issue today, as the science being developed today in the field of ET is amazing. There are new drugs, new technics, new protocols coming down the pipe every few days. One of the vets who does my ET is from Argentina. He has brought some things with him that I have never heard about. Another vet I use, just arrived from Romania 5 years ago, and he has done nothing but ET for more than 20 years. He also brought some new ideas.
There are new drugs presently being tested that will revolutionize ET again, if they prove to be as successful as the early research indicates. I think we will see many new techniques brought into the industry in the next 5 years.
I am not saying that all new things are good, but I think we need to be more open minded now to new techniques and new ideas and be willing to accept the good ones, reject the bad.
I know many people who use heifers for recips. Again, I prefer cows that have calved at least once. If I can choose, I like to use cows that are not still trying to grow themselves so that they can put all their efforts into raising the ET baby.I usually use cows that have calved at least twice and have even used an occasional cow that is 10+ providing their udder is good and they still can stay in condition.