What are the key factors when selecting Superior animals for each area in Chicken production?

For broiler production the factors affecting it will be bird weights , liveability,, contract agreements, and operating factors such as fuel , litter , electricity. Next we have got egg production and for that we have the following factors : hen productivity, feeding system , vaccination schedules , and molting. Pullet production is another area in chicken production and the factors affecting it can be : uniform flock with proper weights, it is the responsibility of the grower to provide a uniform flock under ideal environmental settings , feeding and care. And in the end for the broiler breeder production the factors will be cash operating factors ( fuel , electricity, maintenance) and environmental settings , feeding system as well as vaccination schedules too.