In regards to rasing large fowl hatch as early as possable to keep size up. Jan feb march. In bantams hatch the first chick on March lst and stop about april 20th. That will keep the size down. Bantam breeders up north hatch chicks out like large fowl and most of the bantams are to large. Down here in the south I have found this to be true. This is a method I have done and now all the bantams are done this way. If the eggs do come out early I will sell the eggs to people or hatch the chicks and send them as started birds. But with my heat down here its a waist of time to raise them for show birds. As breeders they are fine.
I hatched some large fowl white rocks a few years ago in June they where one pound smaller than the same baby chicks hatched in Jan and Feb. Why I think the heat slows down the groth or they dont eat as much. The chicks from these smaller birds however, if hatched in Jan and Feb the next year will be normal size.
In bantams Chicks hatched in Jan and Feb will grow larger. Some times I was trying to get a female so bad for my calll ducks or red bantams I would hatch the eggs to try to get one. Every time I raised the little ones up they where so much bigger. I also found if I hatch my birds in may and june they dont feather as well again I live near the Gulf of Mexico near Mobile Alabama its hot and so humid. This may not be a factor in other parts of the county. I Washington State I always hatched my large fowl in Jan and Feb so they would be ready for the fall fairs.
What I am doing this year is I have three small wooden incuabotors. I hatch each breeding pen in say number one, number two and number three I place these chicks in a brooder box and raise them up to say two weeks of age and put a wing band number on each chick so I know what family they are out of. I do however, toe punch each chick to thier pen mating as soon as they go into the brooder box.
I have white leghorn, white plymouth rock, rhode island reds, and buff brahmas and gray call ducks and over the years I have been able to weigh my birds as adults and keep them under the standard weight. This works with two other bantam breeders who are friends of mine who live in North Lousiania and Arkansas. They do it the same way.
There bantams are not large and they have super birds for color and type.
Thats how I do it and it works for me.
You need to buy you a cheap digital scale and weigh your birds so you know if you are in the ball park. In American Breed Large fowl it is better to have your birds at age ten months to be about one pound over standard weight. You get a nice 24 ounce per dozen set of eggs and your chicks will be right on the money.
Hope this helps you. bob