My breeder told me never to feed chickies tomatoes. I don't know why though.
You can make relish from them. There is a recipe in the Ball canning book. If I can find that book I will post you the recipe. If not, go to the Ball web site and see if you can find it. Or try googling green tomato relish and see what you come up with.
I cannot imagine why you were told not to feed tomatoes to chickens. Chickens can and do eat most anything.