Mekonnen, M.M. & Hoekstra, A.Y. Ecosystems (2012) 15: 401. https://doi.org/10.1007/s10021-011-9517-8
preface:
When considering the impact that animal agriculture has on water consumption it is important to put the different animals into groups. The eight groups are beef and dairy cattle, sheep, pigs, goats, broiler and layer chickens, and horses. Buffaloes fall into the beef cattle category, and asses and mules are considered horses.
The water footprint an animal has, includes the indirect footprint of the feed, and the direct footprint of the drinking and service water consumed by the animal. The service water includes water used in cleaning the farms, animals, and maintaining the environment.
For the animals which are purposed after their slaughter-beef cattle, sheep, goats, pigs, and broiler chickens,-it is helpful to look at they’re water footprint when they’re dead, due to the fact that they become products such as meat and leather. For dairy cattle and layer chickens, it is best to look at their foot print per year and relate it to it’s yearly production of milk and eggs.
When considering the water footprint related to animal’s feed it has two parts: the water footprint of the different feed ingredients, and the water that is used when mixing the feed.
Cici's Capstone 