New Study Reveals the U.S. has Reduced Livestock Water Needs Since 1960
A recent study in Environmental International found the United States has improved water productivity and decreased the water footprint of livestock production by 36% since 1960. The study relied on data from the United States Department of Agriculture (USDA) and analyzed the annual U.S. yields of beef, pork, poultry, and milk from 1960 to 2016. The yearly amount of water invested in each class of livestock, the rainfall and irrigation needed to grow grains and other livestock feed, the drinking water that livestock consumed, and the water used to clean the animals and their living quarters were also examined.
Water productivity improved considerably for all investigated livestock products. To calculate a per-animal measure of how efficiently U.S. producers converted water into food, researchers divided the annual weight of each livestock product by the volume of water needed to produce it, then calculated water productivity.
In 2016, milk production was five times more water-efficient than 1960, pork four times, chicken, turkey, and eggs three times, and beef twice as efficient. Mesfin Mekonnen, study lead and research assistant professor with the Daugherty Water for Food Institute, said the increase in productivity is due to a combination of selective breeding, genetic engineering, and supplements that have increased the sheer size of the average livestock, generally resulting in more food from each animal.
With the continued rise in the global population, the demand for water productivity improvements is vital. “Globally, we see that the population is growing, income is improving, and with that, the demand for livestock products is increasing,” said Mekonnen, “When comparing a livestock product to a nutrient-equivalent crop product, livestock demands more water. So, with the increase in demand for animal products, there will be more water demand, creating more pressure on the limited available water.”
The study also found while the total weight of livestock increased 48% over the 56 years, the weight of feed only increased 8%, partly due to breeding innovations and modifications that require less water, contributing to the decreased water usage. “It creates the awareness that we need to look at the full supply chain when we talk about livestock or other products — from feed production to the final output,” Mekonnen said in a press release. “We cannot say this is enough, there is a need to keep on improving.”