Americans would have to halve the amount of beef they eat each week to make the American beef industry environmentally sustainable, according to a team of researchers.
The authors have designed a model for sustainable production where cattle are raised only on grass, hay and food industry by-products. This would free up 32 million hectares of cropland currently used to grow food for cows that could be used to grow crops for humans.
They say their model would reduce the amount of fertiliser and water needed, as well as reducing greenhouse emissions. However, their model produces just under half of the beef the US currently does.
A media release from Springer Nature says a model for the more sustainable supply of up to 45% of current US beef consumption is presented in a paper published online in Nature Ecology & Evolution. (see HERE).
The US beef industry is often cited as a major greenhouse gas contributor, not only from the cattle themselves, but also from the fodder grown to feed them.
Gidon Eshel, Ron Milo and colleagues have defined sustainable beef production as cattle that are raised on grassland (pasture and small amounts of locally baled hay) and food industry by-products, such as distillers’ grains or sugar-beet pulp.
The authors’ model finds that, using this definition of sustainable beef production, an estimated 32 million hectares of cropland currently used to grow fodder could be reallocated for plant-based food production.
The authors suggest this reallocation would also dramatically reduce nitrogen fertilizer and irrigation water use while substantially reducing greenhouse gas emissions. They find combining the change in land use with pasturing could lead to 45% of current beef production being sustainable.
In addition, they find that halving the size of existing pastureland used (to about 135 million ha), by abandoning less productive grasslands, can still sustainably deliver 43% of current production.
Finally, they show that a reduction in beef consumption from the current level of about 460 g per person per week to about 200 g per person per week could make the entire US beef industry environmentally sustainable (by the narrow definition of the paper).
The authors emphasise that this is just one possible model and definition of sustainability, and caution that any model must maintain protein needs.
Due to the very low feed-to-food protein conversion efficiency of beef, however, reallocating feed land to all considered plant alternatives at least maintains protein supply, and reallocation to such protein-rich plants as soybean, for example, increases protein production from the land five-fold.