|MadSci Network: Agricultural Sciences|
This is an interesting question, but is almost more philosophical than scientific. In theory we can genetically engineer whatever traits we can figure out how to do. But I think the better question is what would happen if you took a modern broiler chicken and raised it less intensively -- I'm not quite sure, but it should simply grow slower as long as it is provided with reasonable conditions. It probably is not as tolerant of extremes of heat and cold as the typical barnyard strains, so it will need more attention. I should also point out that there is not one "native" chicken. We use many different strains around the world. So, hopefully, these comments provide a reasonable answer for you.
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