There are not only strong opinions but also scientific studies suggesting that consumers should switch their dietary habits to include fewer animal products to reduce the environmental impact of one of our very basic needs, food. Emissions from the livestock sector are a major concern with around 12% of all human-induced greenhouse gas emissions, and much of this falls on the ruminant sector. Ruminants are, in short, animals able to get nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, mainly through microbial conversion. Ruminants include, for example cattle, all domesticated and wild goats and sheep, and more.
As ruminants are able to convert roughage feed (or dietary fibre) like grass, hay or food by-products unsuitable for human consumption into edible food products (meat, milk), they have been a valuable resource since the early human societies. Also, ruminants can thrive well on poor productive land areas which are unsuitable for crop cultivation.
In order to mitigate the greenhouse gas emissions from the ruminant sector, we must look for other sustainable strategies than just reducing the number of animals. In recent years, silvopastoral systems have received increasing attention. Silvopastures are an important element of traditional rural landscapes, combining forests and cattle in the same area. However, over the past decades silvopastoral systems were largely abandoned or lands were converted to arable land or commercial forests. New studies suggest going back to silvopastures is a potential form of sustainable intensification that allows the mitigation of greenhouse gas emissions from livestock through the carbon sequestration of trees, while not adding emissions by producing additional feed which is needed when cattle, for example, are kept indoors. Silvopastures don’t pose a conflict between food and feed production.
During a three-month traineeship at EFI, I worked with the AFINET-project and evaluated the greenhouse gas emissions and carbon sequestration in different beef cattle production systems in Finland. These were: forest pasture, wood pasture, pasture and indoor system.
The emission related with the enteric fermentation, which is the digestive process for cattle, affects significantly the result of the total greenhouse gas emissions, especially in the forest pasture system due to the large amount of rough feed, such as forest understory, eaten by the animal. Emissions from feed production, in this case grass-silage and barley, are also significant because they include the emission related with agronomic practices such as fertilization and ploughing.
In the forest pasture, wood pasture and pasture systems there is a component of carbon sequestration. This uptake is able to balance most of the emissions generated from the beef cattle production system, especially in the silvopastoral systems where trees are present.
My conclusion is that the restoration of the silvopastoral system might help mitigate the greenhouse gas emission related to livestock but further studies are required in order to investigate which are the best management practices in silvopastoral systems to make them carbon neutral.