Livestock is responsible for 12% of greenhouse gas emissions related to man. This percentage comes mainly from the change in land use and deforestation caused by the expansion of agriculture, as well as the methane released by the animals themselves, plus a small part that comes from manure management and feed production.
A new study, published in the journal Proceedings of the National Academy of Sciences, shows that within current systems, farmers would find it more profitable in the coming years to increase livestock production in mixed systems (where livestock are fed both fresh grass and high-quality feed) rather than systems based In just grass.
This development would lead to a 23% reduction in emissions of land use in the next two decades without the need for climate mitigation policies.
Cows, sheep, and goats grow rapidly and produce more milk when they eat energy diets that include grain supplements or improved forages. This means that the number of animals can be increased on less land, with fewer emissions per kilogram of meat or liter of milk produced.
The new study foresees that the rising cost of land and the continuous increase in yields in the agricultural sector will lead to changes in animal diets in the future. These types of diets are efficient, not only from the point of view of reducing greenhouse gases but also of maximizing agricultural profit and food production.
In previous works, carried out by the same group, a detailed database was made highlighting the differences in the efficiency and greenhouse gas emissions of the different livestock production systems.
The new study adds to this by examining the economic potential of a transition to more efficient systems as a mitigation measure, highlighting the policies that would be most effective in reducing greenhouse gas emissions, while maintaining food availability.
Changing livestock production systems remains a challenge. The researchers say that policies to improve education and provide access to markets are key to triggering change. In addition, they point out that safeguards to ensure that intensification of agriculture does not lead to harmful environmental or reduce animal welfare.