hi jim
a mate of mine in kent breeds his ybs in march and never lets them out till september,he breeds 40 or so ybs and lets them out say on a saturday he will have no birds in his loft for about 2days when they start drifting back by the following saturday he would have most of them home he would then start to train them he would give them 4 or 5 tosses working them up to 60mls then leave till next year,i think that most of the losses are down to the fact that we may be breeding off sub-standard stock thats not been tested and i mean sent to the distance of say 500mls any that come home you breed from them.if we only sent them say 300mls and no further we all would a loft full of untried birds ,we must allways set a test for every bird over the yearling stage and if they pass the test ok,just my opinion jim