It one of the laws that nobody follows. Just like laws about shipping eggs or birds are not followed.
Don't know anyone that pays taxes on those earning either.
I know of lots of people who sell turkeys that they butcher. Thats how I first tasted a home grown turkey, was buying from them. They sell to co workers and neighbors. As long as you don't put a add in the newspaper or doing it large scale, nobody is out looking to see if your selling turkeys...