OH MY GOSH,
You may all disagree with me and that is fine. Everyone has opinions. I will never tell anyone what to or not to do with their birds/animals but when the time comes that I have to start plucking/trimming feathers from a chickens butt to get fertile eggs then I'm out of the chicken business. Holy catfish, I never heard of such stuff.
Got to tell this story. For quite a few years I bred German Shepherd Dogs, back in the 60's. Probably about 15 years ago I decided I wanted to get some really good stuff and I bought a male from over seas and had him shipped in to me. It cost me all but $6000.00. I had a very nice female and when she came in heat I turned the male loose with her and nothing. I'm not going to go into all the details except that I contacted the breeder and he sent me a video and pictures and said that this was what they did. They actually held the female and got down on the ground and got hold of the male and inserted him into the female. Oh my gosh, I about fell on the floor when I saw what some folks do. Needless to say, I don't breed dogs of any kind anymore. If that dog is that stupid that he doesn't even know how to do something as natural as breeding a female then I sure would not want any pups out of him.
I can say that I have had 5 or 6 different lines of the RIR's over the years and the only time I have had a problem with infertility was a couple of years ago in the really cold weather and it was with my RC Reds but the weather was really cold (like -35 degrees wind chill) and I had a really hard time until it warmed up. Real recent, I had a problem with some of my older males but I know it is because their spurs are toooo long. I've watched them and can only hit maybe 1 out of 3 or 4 times. They usually end up just giving up.
Just my thoughts and everyone can do what ever they please. If a bird or anything else can't breed naturally then I don't want them. I will stick with the ones that can. I know that folks do this but me personally, I never will. I had paid $470.00 for a pair of English orpingtons a few years ago and never had one fertile egg from them. The hen ended up dying and I butchered the cock bird. Expensive meal but that is just how it goes.
This is just my two cents worth and I'm sticking to it. I've got a whole lot more to do then to be a chicken butt plucker. Just saying.
Jimmy