Is selling breeding rights to your animals as "pets" legal?

So I have a fairly rare breed of egg-laying chicken that most people are interested in because of the rarity and selling them as pets, and the rarity is what they're looking for. Now, I do sell them as pets; however, I reserve the right to buy them back or return them to my farm at any point in time if I want to breed them. There is a contract that I make the person sign, and all of that, that essentially says that they're buying them under the understanding that they'll return them to me if I want to breed them, but they can continue to use them as pets until that point. My only concern is that selling them as pets, and then saying "Oh, I'll want to buy back this chicken in three years to breed it" is illegal in some way. I want to do it the right way; I don't want to get taken to court. I also don't want to burn bridges by selling them as breeding chickens and then getting annoyed calls about how long it took, and why I didn't I just give them the chickens, when it comes to breeding chickens. <br><br>I just want to do this the right way.