Number of Animals Killed Annually

The numbers quoted in this statistic vary between 40 billion and 3 trillion.
The smaller number pertains to land animals (sometimes only mammals) and the latter includes all sea life including shrimp and other small creatures.

Primary Source

While the Food and Agriculture Organization of the United Nations database is an incredible resource for information, it does not provide bite sized information.

Eurostat shows easier to digest numbers for the European Union, though broken down by animal type so you need to do some maths yourself.

Meta Summaries

BiteSizeVegan has an excellent article covering the difficulties in calculating these numbers and the guesswork that goes into it.

TalkVeganToMe Verdict

Precise numbers are not possible for this statistic, and further research is required by the writing team to come to estimates we can get behind. However the deaths for land animals are incontrovertibly in the billions, and you have to ask: does it really matter if it’s 40 billion or 60 billion animals killed needlessly?