Here is how it works in my state, YMMV. Every state allows for a certain number of on-property sales, regulated by the federal government. The Federal standard is 1000, some states differ but everyone allows atleast 1000.
In Ohio, I can take my birds to a state ag inspected facility and sell off property. I have a processor that is state ag certified so I can legally sell my birds in the state.
There are a few ways around/within the laws.
First, sell the bird before it is dead. If you have a contract with a purchaser while the bird is alive, you have in effect sold them a pet. Now if the pet were to die prior to delivery, and the pet were bagged up ready for use, then it would be a pet sale.
Second, sell on property and live within the federal exemption.
Both of these require your customer to come to your property, almost every state requires off-farm (Farmers Markets included) sales to occur within some kind of inspection guidelines. Unless your 4H extensions have permission for the club members to sell at a farmers market, uninspected.