Feeding straw to suckler cows spared land but did not decrease the climate impact of beef

Beef has a considerably higher climate impact than meat from monogastric animals and plant-based foods, due to methane emissions from enteric fermentation in ruminants. Animal feed production also contributes considerably to the climate impact, through carbon dioxide emissions from fossil fuel use and nitrous oxide emissions from soil. Despite this, ruminant animals can still be part of sustainable food systems, as they can produce human-edible food from coarse biomass unsuitable for human consumption (e.g., grass or straw), i.e., acting as ‘upgraders’. Feeding ruminants on coarse biomass also reduces the need for cropland for feed production. Using cereal straw as indoor feed for suckler cows reduces their feed intake in winter, while increasing their intake of biomass on pasture during the grazing season. This study assessed the climate impact of producing 1 kg of beef (carcass weight), and of the farm as a whole, in a Swedish suckler-based system using a mixture of cereal straw and grass-clover silage as winter feed for suckler cows, compared with using only grass-clover silage (reference scenario). The rest of the feed remained unchanged. Replacing part of the grass-clover silage with straw meant that less cropland area was needed to grow feed. Two alternative scenarios for using this spared land were investigated: producing wheat for human consumption (straw-food) and conversion to pasture (straw-pasture). Effects on total food production were also calculated. Using a combination of cereal straw and grass-clover silage as winter feed for suckler cows was found to reduce the climate impact associated with feed production compared with using only grass-clover silage. However, this change in winter feed increased biomass intake on pasture during the grazing season and thus the grazed area, so total climate impact of beef per kg carcass weight, and of the farm as a whole, increased when the demand for more grazing area resulted in deforestation. With no deforestation, the climate impact was comparable to that of beef from suckler cows fed exclusively on grass-clover silage during winter. Therefore, upcycling of straw to meat had no notable effect on the climate impact, indicating that using residues as feed does not always entail a climate benefit. However, increased demand for pasture can have a direct benefit for biodiversity if more biologically rich semi-natural pastures are maintained or restored. Using the land spared through feeding straw instead o