Animals
used on farms make up the majority of those raised and
used by humans, with an estimated 33 billion
land animals alive at any given time.18 This estimate is more exact than any other we will consider, since governments conduct counts of livestock
in order to understand and
regulate local economies.19 However, this is a somewhat similar undercounting to what we saw for lab animals: fish and shellfish are not counted, and
in some areas they are raised for consumption
in large numbers.20 The estimates also neglect other animals
used for food, such as wild fish or commonly hunted
land animals, although these animals may be affected by some of the advocacy aimed at helping farmed animals through promoting diet
change.