Livestock supply chains are a major source of nitrogen emissions and the sector requires a global initiative to tackle pollution, says new study.  

The article, published in the Nature Food research journal, assesses the livestock sector’s impacts on global nitrogen flows and emissions including international trade.

Application of synthetic nitrogen fertiliser and manure, and the transport of nitrogen-rich products such as feed, each contribute to global nitrogen flows, according to the research.

The study was carried out by Aimable Uwizeye, livestock policy officer at the UN Food and Agriculture Organization, and his colleagues. Uwizeye says that the nitrogen pollution emitted by global livestock farming is now threatening environmental and human health, with significant impacts on climate change and biodiversity losses.

In response, the group urges the livestock sector to implement a global initiative to tackle nitrogen pollution, while supporting food security. The study helps identify opportunities to improve sustainable nitrogen management, while increasing livestock systems efficiency and reducing environmental impacts.

The study covers 275 countries and territories grouped in 10 different regions and analysis was based on the updated Global Livestock Environmental Assessment Model (GLEAM) developed by FAO.

The analysis shows that the livestock sector emits roughly 65 teragrams a year, which is equivalent to one-third of current human-induced nitrogen emissions. Of this amount, 66% is allocated to Asia.

Ruminants systems (cattle, buffalo, goats and sheep) release globally 71% of total nitrogen emissions from livestock, with the production of eggs and meat from chicken and pork contributing to the remaining 29%. 

The study suggests that incentivising farmers to collect, transport and recycle manure to available croplands could help reduce nitrogen emissions, as well as designing a livestock production system that is spatially less concentrated.

Matthew Knight, chief executive of RABDF, believes much of the information currently being reported in the media overstates the impact of dairy cattle on the environment.

He told FoodBev: “Livestock farming, particularly cattle production, has been facing increasing amounts of pressure for the perceived impact that cows have on the environment.

“The reality is dairy production accounts for only 3% of total GHG emissions. While there is always room for improvement when it comes to farming’s environmental footprint, so much of the criticism levelled at dairy farmers and the sector has been incredibly unfair.

“Not only can statistics around carbon footprints and greenhouse gas emissions be incredibly complicated, but much of the information currently being reported in the media overstates the impact of dairy cattle on the environment.”