March 2, 2020

 

Study finds US substantially improved livestock water productivity

 

A Nebraska's Daugherty Water for Food Global Institute study found that water productivity for cattle, swine and poultry industries in the United States has improved from 1960 to 2016, reported The Grand Island Independent.

 

Using data derived from the US Department of Agriculture, the study considered beef, pork, poultry and milk output in the United States from 1960 to 2016 and the annual water amounts invested into each livestock class. This included the rainfall and irrigation required for livestock feed such as grains, drinking water and water used for cleaning the livestock and facilities.

 

The study's results showed that water productivity for beef, pork, chicken, turkey, milk and eggs have gradually improved throughout the 56 years. Compared to 1960, by 2016 the United States produced beef twice more efficiently, poultry and eggs three times better, pork four time better, and milk five times better. In total, annual water investments dropped 36% within the 56 years.

 

MesfinMekonnen, lead author of the study and Water for Food Institute research assistant professor said the estimated world population growth means there will need to be further improvements in water efficiency, as a bigger population boosts demand for livestock products.

 

Mekonnen said water productivity improvements are the result of selective breeding, genetic engineering and livestock feed supplements that have increased the average livestock size.

 

The research also found that efficiency of livestock converting feed to meat, milk and eggs has also improved. Not only has livestock feed been modified or bred to use less water, the weight of livestock has only gone up by 8%.

 

While beef represents the lowest water efficiency improvement among livestock in the US, cattle represents close to half of all the country's livestock water footprint. Mekonnen said environmental sustainability must take context into account, citing cattle in the Nebraska Sandhills that consume grass inedible by humans and raised on rangelands that cannot be used for other crops.

 

To futher improve water productivity, Mekonnen said the diets of livestock such as grain-fed cattle can be altered, such as replacing corn and soybean with distiller grains. These are the byproducts of grains distilled for biofuel use. Distiller grains may contain more protein and provide more energy compared to corn and soybean meal, possibily resulting in a 5% water productivity increase for beef and poultry, 10% for pork and 20% for milk production.

 

Mekonnen said the entire supply chain, from feed production to the final output, must be considered when assessing livestock.

 

The study was published in the Environmental International journal.

 

-      The Grand Island Independent