A Global Assessment of the Water Footprint of Farm Animal Products

TLDR

Increasing animal product consumption and intensification of production systems are projected to further strain global freshwater resources. This study offers a comprehensive assessment of animal products’ water footprints across production systems and feed compositions by country. The assessment attributes the high water footprint to poor feed conversion efficiency and analyzes production systems and feed composition across countries. The analysis shows that animal products account for about one‑third of global agricultural water use, have 1.5–20 times higher water footprints per calorie or protein than comparable crops, and that industrial systems consume more water and pollute more than grazing or mixed systems, making crop‑derived calories, protein, and fat more water‑efficient.

Abstract

The increase in the consumption of animal products is likely to put further pressure on the world’s freshwater resources. This paper provides a comprehensive account of the water footprint of animal products, considering different production systems and feed composition per animal type and country. Nearly one-third of the total water footprint of agriculture in the world is related to the production of animal products. The water footprint of any animal product is larger than the water footprint of crop products with equivalent nutritional value. The average water footprint per calorie for beef is 20 times larger than for cereals and starchy roots. The water footprint per gram of protein for milk, eggs and chicken meat is 1.5 times larger than for pulses. The unfavorable feed conversion efficiency for animal products is largely responsible for the relatively large water footprint of animal products compared to the crop products. Animal products from industrial systems generally consume and pollute more ground- and surface-water resources than animal products from grazing or mixed systems. The rising global meat consumption and the intensification of animal production systems will put further pressure on the global freshwater resources in the coming decades. The study shows that from a freshwater perspective, animal products from grazing systems have a smaller blue and grey water footprint than products from industrial systems, and that it is more water-efficient to obtain calories, protein and fat through crop products than animal products.