I have some Cornish X that are small for their age, but I have attributed this to the shorter day lengths. I also have been experimenting with limiting their feed. They free range, have a lot of green stuff available, they were being raised by a broodie up until this week, at which they were 6 weeks, they are between 1.5 & 2.5 lbs approximately. They run with the flock, so I don't know how much they are eating, but their crops are always full and they feel quite plump. Between them 9 CX & 14 hens, they eat 2 lbs of 20% starter, 1/4 lb flax seed, 1 lb of oats, 1 lb scratch, plus clover & grain forage that I'm growing. They are very active and will actually go out further than the hens to forage. I am doing this to see if they will taste different, and hopefully increase the omega-3 fats in the meat. I've raised them before, letting them free range, but providing more feed, and found that after a time they wouldn't want to forage much and when they were processed I thought they tasted very similar to the store bought, just fresher and a bit more texture. I am fortunate that I live in a mild climate so I don't think they are that affected by the weather, right now it's like spring in other parts of the country.