But with only roosters, he would have to buy and resell. Would there be enough profit to compensate for the feed and effort through the growth stage? Honest question.
And the fighting could be there and as such a possible legal avenue.
Could he be into bird fighting - directly or indirectly? Animal welfare laws could come into play, though very hard to prove.
Otherwise, he is buying and reselling (likely very low margin of profit) and will lose interest in the project (maybe).