tried it some 10 years ago, I had a video of the Samson brothers from the states .takes a lot of your time up . I managed to get them to their 2ND and last flight before the first race ,and all through the body moult, you do have to pull every 2Nd tail feather and when half way up pull what's left,also you have to breed early youngsters. Samson bro had there young birds on widow hood and their results where outstanding. hope this helps. PS if you don't pull the tail they keep it as yearlings wullie g .