$500,000 is too little to start a commercial chicken farm in US. You can contract with Tyson or other companies who help you get loans, but that will potentially turn out to be a debt trap.

$500,000 is a decent amount to start chicken business in Nepal though. PM me if you are interested to invest in Nepal. I have very close friends in poultry business, two of them returned from US. I will be happy to link you. I personally do not have much idea.

If you prefer to stay in the US, best wishes for your GC!