 But because it's so effective, it's become a completely dominant force in the poultry industry, in all animal feed, in fact, all over the world. The huge demand for cheap soy means that much of it is not sustainably farmed. Soy plantations have caused huge deforestation in the Brazilian Amazon. It's a real dilemma for Peter with his ambitious environmental targets. But at present, there aren't really many other options on the table.