Comment from Michael Fisher

Age is a poor parameter for defining a standard of identity for any class of poultry because it is not easy to verify at slaughter and the size of the bird, not the age, primarily determines its use. If I want a whole chicken for roasting, size not age matters. If age is the determining factor, not only will establishments need birth date information for every flock slaughtered, but OPPD, LPDD will be unnecessarily burdened with explaining how to verify the accuracy of the information on the label. If weight is the determining factor, label verification is easy. Pick up a carcass and set it on a scale. Low tech and no burdensome documentation.