Over the years had a few problems with Y.B.S. But can honestly say most years have reared a few late breds (june /july hatched) out of stock birds, (Generally hatched by mistake)put them in a section on there own given them an open hole when ever possible and let them get on with it.Never a problem burn the skies out, picture of health and are trained as normal following season with the oldens. A couple over the years have been my most consistent 2/3 year olds.