We are in South Florida, raising ducks, chickens & goats with all organic feed and rotating yards for wach age group. All grow up fine, except that the 2 different times we bought St run cornish chicks (from 2 different hatcherries) they grew up to the age of 4-5 weeks, slowed down on the growing, ate far less for a few weeks and, of course they ended up dressed at about 3.5-4 lb at 8 weeks. Tractors are not suitable for the Florida sun. We allowed them to go out to a yard (far smaller than my other birds use). I can say we lost less than 10% but on the other hand, we want to get at least 4.5-5 lb dressed birds. Any advice? Thanks!