Since the agricultural revolution which began around 12,500 years ago, humans have domesticated animals to serve their needs, and hunted others from the wild. For the food system animals have been essential as a source of food, labour, and organic fertilizer while ownership of animals may also have cultural, economic or symbolic import. Industrial farming techniques have allowed for large scale production of animal products, which has raised new ethical concerns about their welfare and more fundamentally about the morality of using animals for human purposes. The resource-intense nature of livestock production has attracted attention from researchers, civil society and policymakers alike. Finally, zoonotic diseases, those which can be spread between animals and humans, are a common source of human infection.