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.