By-products are vital in future livestock production systems

Future livestock production systems face several challenges. The global human population is growing and the demand for animal source food is predicted to increase as incomes rise, although variations in demand will be notable due to differences in peoples’ dietary choices and trends between regions. Besides, more than one billion people depend on livestock systems for their livelihoods and food‑security. The demand for livestock products must be met without increased greenhouse gas emissions and on current agricultural land area, where the production of feed crops and to some extent grasslands also compete with food‑ and biofuel production. Thus, we need to refine the livestock production systems so they become more resilient, sustainable and low in emissions of greenhouse gases and other pollutants per unit of nutrient value. Accordingly, there is a need to find alternative or novel feed resources and improve management strategies that maintain or enhance the productivity and health of the animals. In the concept of sustainability we also need to consider the animals’ welfare, ethics and the one‑health perspective, the farmers’ economy and their working environment. Furthermore, food must be safe and healthy for the consumers and the society must accept the production. The quest for these solutions require interdisciplinary approaches and close collaboration with stakeholders.

Today, around 30% of dry matter in animal diets (global average) consist of by‑products from the food‑ and biofuel industry. Some by‑products are rich in fiber, and others contain more of protein or fat and they have different values as feed for different animal species. By‑products are cheap, but selling by‑products as animal feed is still important for the economy of the food industry. Using the by‑products means that resource management is maximised and that the environmental burdens can be distributed on more fractions of the crop. By converting the by‑products, which are of low value elsewhere, into nutrient‑rich foods of value in the human diet, the animals recycle and upgrade important nutrients in the food chain.

In my research I have worked interdisciplinary and with stakeholders, modelling a range of scenarios to investigate effects of livestock production systems (using by‑products), as well as human dietary choices on environmental impact. I have also performed a number of controlled animal experiments using e.g. high content of by‑products in ruminant diets and assessed the environmental impact, including measurements of enteric methane. To reduce the enteric methane from ruminants, several feed additives have been investigated worldwide. One of the more promising is to add red algae to dairy cow diets, and work in our research group has contributed to this field. In addition to dietary measures, refined management strategies and increased efficiency can reduce environmental impact from livestock. One strategy that I have been involved in testing is to model alternative replacement strategies in dairy production and thereby increase the cows’ longevity.

In my future research vision, I plan to continue to evaluate alternative feed resources to livestock and the effect on production and environment as well as feed additives for mitigation of enteric methane. There is also a need for increased knowledge of how we use the land and the crops for animals in the most resource efficient and low‑emitting way. We need to know more about trade‑offs; e.g. grazing, which in some landscapes can contribute to increased biodiversity, while the emissions of enteric methane increase, and efficiencies of low input‑output systems. In addition to research regarding environmental sustainability, I want to expand the interdisciplinary research to include evaluations of drivers for change and socio‑economic sustainability factors relevant for livestock production systems.