Is the line breeding plan that is discribed on here, where you breed parent/ child to 7/8 pick the best and start agian, not the same thing as the sppa calls a rolling mating? where the young males mate with the old hens and the old males with the pullets? I am asking because the sppa article talks of having 10 females in each group and the 3 in and one out program, speaks of pairs. does anyone use a rolling mating with less than 20 female?