It is perfectly possible to live on a vegan diet with no animal products, so why do we bother to keep animals at all? Is it simply that animals produce a convenient collection of nutrients that are not always easily available to vegans? In part at least, it must be a question of tradition. ‘Farm animals’ considers what farmers need to know in order to make their animals grow quickly, and put on the right combination of muscle and fat that butchers prefer, or produce lots of milk or eggs or wool. They require knowledge of: feeding, breeding, housing, health and disease control, and the type of production system to be used.