Use of by-products increases land and water resource savings

While animal-source foods contribute to 16% of the global food supply and are an important protein source in human diets, their production uses a disproportionately large fraction of agricultural land and water resources.

Replacing energy-intensive crops with agri by-products

The study showed that an 11-16% substitution of energy-intensive crops currently used as animal feed, such as cassava and cereals, with agricultural by-products would save between approximately 15.4 and 27.8m hectares of land, and 3-19.6 cubic km and 74.2- 137.9 cubic km of blue and green water, for the growth of other food crops.

Animal food production can compete with plant food production

This saving of natural resources, the researchers say, is an appropriate strategy for reducing the unsustainable use of natural resources both locally and globally, through virtual trade in land and water. It also shows that animal production can, therefore, compete directly or indirectly with plant food production.

Agricultural products are defined as secondary products derived from processing primary crops such as cereals and sugar. The study involved looking at cereal bran, sugar beet pulp, molasses, distillery residues and citrus pulp.

Camilla Govoni, researcher at Politecnico de Milano, Italy, said not only did the use of agricultural by-products in animal diets decrease competition between sectors and pressures on resources, but it would also increase the availability of calories that can be directly earmarked for the human diet: “If the saved resources are used for other purposes, including production of plant foods lacking in current diets, it would improve food security in several countries, with healthier as well as more sustainable food choices.

The use of alternative ingredients in animal diets would lead to increased sustainability and reduced environmental impact not only locally, where the company raises and produces meat and animal products, but also over large distances.

Maria Christina Rulli, professor of Hydrology and coordinator of the Glob3ScienCE Lab, added that a decrease in demand for feed could lead to less importation of feed, producing economic and socio-environmental benefits: “The production of certain feed products actually corresponds to over-pressure on water resources and deforestation, with consequent effects on the concentration of greenhouse gases in the atmosphere and loss of biodiversity.”

Inter-sectoral decrease in demand of cereals

She said the inter-sectoral decrease in the demand for cereals was especially important given the supply of such crops was in jeopardy due to the Ukraine/Russia conflict, the residual effects of the Covid 19 pandemic and extreme weather conditions induced by climate change.

The main challenge is thus to explore innovative feeds that may work as an alternative to conventional ones

Innovative nutrition

Luciano Pinotti, professor of nutrition and food at the University of Milan, added that by converting fodder and agricultural by-products into high value-added products and services, animal production was making a fundamental contribution to the bioeconomy. “Livestock farming is often held responsible for a significant global environmental impact, which is why it is essential to rethink animal nutrition in particular, as it is one of the main reasons for competition for resources.

The approach must be to develop “smart animal nutrition”, where research must come up with solutions to increase animal protein production without increasing the environmental footprint of animal protein. Hence the importance of studying animal nutrition not only in terms of competition but also in terms of synergies and complementarity with human nutrition so as to optimise the utilisation of nutrients in the food chain. The main challenge is thus to explore innovative feeds that may work as an alternative to conventional ones, possibly do not compete with human nutrition, are part of the circular economy, and are intended with a view to “one nutrition”.

The study “Preserving global land and water resources through the replacement of livestock feed crops with agricultural by-products,” is published in the journal Nature Food – Preserving global land and water resources through the replacement of livestock feed crops with agricultural by-products | Nature Food