What animal byproducts does Yarrah use?

Stomachs, hearts, liver and kidneys are used in our products. No feather meal or blood whatsoever are used. Why do we use these animal byproducts? It would be a sin to throw away these useful byproducts. After all, heart, kidneys and liver contain plenty of essential minerals and vitamins. Stomachs contain plenty of proteins and very little fat. By adding these products to our food we are preventing food waste and it enables us to add an extra source of vitamins, minerals and proteins.