Figure 1: Upper figure: linear agricultural model; lower figure: circular agricultural model.
Global consumption of animal-source foods is highly dependent on geography, income and education, and can have different impacts on human health and the environment depending on consumption patterns and production conditions. Animal-source foods affect the following environmental areas:
- Land use: Livestock farming takes up about half of the world's available agricultural land. About 50 per cent of this land comprises grasslands that cannot be used for crop farming. The development of new land is often accompanied by deforestation and land degradation. In many cases, there is competition between feed and food production.
- Soil: Both grazing behaviour and livestock manure contribute to ecological and biogeochemical soil processes and soil fertility. As the most widely used fertiliser in the world, livestock manure is also indispensable for crop cultivation. However, excess use leads to nutrient losses and adversely affects aquatic ecosystems.
- Water: Livestock use about 40 per cent of the world's agricultural water. More than 90 per cent of this amount is "green water", which comes from rainwater. Thus, there is no competition for water when grazing is practised on land unsuitable for cropping.
- Biodiversity: The destruction of intact habitats for grazing and animal feed and the use of medicines in animal husbandry and pesticides in crop farming, lead to significant biodiversity losses. However, livestock farming can also help to preserve natural grasslands and, thus, biodiversity. In Europe, grassland habitats are among the ecosystems with the highest biodiversity.
- Climate: Livestock farming leads to high greenhouse gas emissions. About 30 per cent of global methane emissions come from animal husbandry. However, pastureland soils also contain about 20 per cent of global soil carbon. The underlying agricultural practices significantly influence the amount of greenhouse gases emitted.
- Circular economy: Using livestock manure as fertiliser for pastures and crops is an essential aspect of the circular economy. The use of harvest and processing residues as animal feed also helps to close production cycles. This particularly concerns ruminants such as cows, as they can convert fibrous plant material into high-quality proteins.
Figure 2: Overview of impacts of livestock farming on land use, soil, climate change, biodiversity and water. GHG: greenhouse gases, C: carbon, LUC: land use change
Relation to biodynamics
Whether livestock farming harms humans and the environment, contributes to climate change or represents an integral part of a sustainable circular economy depends on various factors. If we look at livestock farming – particularly cow husbandry – from a biodynamic perspective, a clearer picture emerges of the ecological impact of cow husbandry and the sustainability concept of biodynamic agriculture.
A central idea of biodynamics is the farm organism, meaning the synergistic interlocking of all farm parts in a circulatory system that is in harmony with the natural environment. Cows are essential in this system as they provide several valuable services. As ruminants, they can convert tough plant parts and crop residues into high-quality proteins and nutrients. When cows graze, they loosen the soil and improve the air and water balance of the soil. In addition, their manure is rich in nutrients, promotes plant growth and improves soil fertility. The circular economy produces much of the animal feed itself, and this practice reduces carbon emissions associated with imports. In addition, biodynamic farmers typically grow various crops that they use as feed for their cows.
Biodynamic agriculture does not require concentrated feed such as soy, thus reducing deforestation in tropical countries. The cows' water needs are almost entirely covered by rainwater and lush grass. Their grazing behaviour promotes soil fertility and carbon storage in the soil. They also prevent the overgrowth of pastures. Their feed comes from the farm and does not compete with human food. Their stocking density is low and adapted to ecological capacities. Under these circumstances, cows are not only an essential part of the farm organism but also part of long-term sustainable and environmentally sound agriculture.
Details of the original research paper
- Authors: Beal, T., Gardner, C. D., Herrero, M., Iannotti, L. L., Merbold, L., Nordhagen, S., Mottet, A.
- Title: Friend or Foe? The Role of Animal-Source Foods in Healthy and Environmentally Sustainable Diets
- Journal: The Journal of Nutrition 153, 409–425 (2023)
- Link: https://doi.org/10.1016/j.tjnut.2022.10.016