 This is the third string to Peter's environmental bow. He's running what he calls a circular farm system. He uses the poo from the chickens to fertilise his crops, in this case wheat, and then he uses some of his wheat to supplement the chicken feed, and the straw from the wheat also feeds his biomass boilers, which go to heat the chicken sheds. It's a smart system, a tight little loop of generation and consumption, which makes the farm pretty efficient, and it does bring his carbon footprint down. That's kind of what all this boils down to.