Well, I'm only part way through my DC experiment, so my input will be incomplete.
Dark Cornish will take much longer to grow out than either of the hybrids you have raised, and the first batch will not be anywhere near the size of those birds. I just butchered half of my 20 week old DCs and their size left something to be desired. However, while smaller than the RIRs and Buff Oprington that I raised at the same time, their breast meat was far more substantial comparatively speaking and the texture and taste much better.
The size was a little deceiving, though, because I kept out the largest for my laying/parent flock because I'm trying to build onto their size. Plan is to keep these 9 hens and 3 roosters (one of them is extra for insurance, in case something happens to one) and hatch out a week's worth of eggs at a time, which should be close to around 50 per batch. Then skip a week, collecting those eggs for consumption, then another week for hatching, etc. I don't think it will require 25 birds to keep a family of four in eggs and meat, but I guess that would depend on your consumption level.
Guess I'm saying 25 would be a bit high in my view, but it would certainly do the job.
I will let the board know whether my scheme works in the spring and summer, though.
