You can just grow some birds out and breed a few of them to have more. Or you can breed them for a purpose.
They don't actually need all that protein at that stage in their growth, but the high protein puts a layer of fat on them. Some people want that for meat birds, some don't. I do. If I still lived in the North, I would want a bit higher protein in the winter, helps keep them warm. But for the breeders they don't need it and it could interfere with their fertility. Just like any other bird we breed. That is why breeders are pulled from the growers as soon as they can be identified and put on a diet for breeding/laying. But not everyone does that, and for different reasons.
Growers don't need the calcium either, but the layers do. Layers being another facet of raising these birds. Some people raise them to get the layers to sell the eggs and that is all they are really interested in. So they have growers, layers and breeders or have their breeders in with the layers. But if you are raising them to increase their size you want the breeders separate from the layers. You want the largest breeders for meat breeders and the smaller but good size for the layers and layer breeders. Which are kept smaller for laying efficiency purposes, they don't need to be bigger. Actually bigger birds lay less eggs supposedly, just like in chickens. If you are raising both, you need breeders for both purposes.
I don't know what to tell you on protein. I have used Purina startena at 30% when I couldn't get my brand when I switched them to that at 28% protein, they grew faster it seemed. I think it depends on what the % is made up of. What the recipe is when the %'s are that close. What the weather is like where you are. A lot of different factors. Like stress, enclosure, etc. If my order doesn't come in tomorrow, I to will be using 24% and they will grow out however they do.
But for big birds, you need to start your own line if you don't have access to one. That is, selectively breed for size and that takes a high protein. Generation after generation... It will take 10-12 generations to get a 12-16 oz. bird, if you start with a standard. (from what I've read). We'll see. I have Jumbo Browns, but my birds will be improved by end of next year, they are close. If a hurricane don't get us or our world fall apart. Who knows what tomorrow brings, but that's the plan anyway.
Hope I didn't confuse you. But they are raised for different purposes (and there are other purposes too besides meat, eggs and varieties). That is why it seems there is conflicting information out there. So you decide, are you raising them for the eggs, and some meat? Or are you raising them for meat birds and some eggs? That is what I'm doing or will be if all goes well. 24% protein will slow me down, but not stop my little project, cause I have eggs to suppliment my babies with.
