Nothing that technical.
All chicks are wing tagged and I keep records of simple things like weight at 9 weeks, age at first lay, temperament (calm hens are more productive), and moult (date and length of time unproductive). Broodiness I don't want in my Light Sussex flock, therefore any sign of broodiness and they are moved on. I hope to use my pure Indian Game pullets as broodies.
I just want to keep a small flock of traditional pure breeds, where the Light Sussex can produce eggs in acceptable numbers and cockerels make a worthwhile meal. The Indian Game will hopefully add extra meat yield to the first cross.