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“What a Waste” – Can We Improve Sustainability of Food Animal Production Systems by Recycling Food Waste Streams? Part I

By Dr. Gerald C. Shurson, UMN Swine Nutrition Professor, Department of Animal Science

Originally printed in The LAND – September 18/September 25, 2020

Crises often lead to change. For far too long, food waste has been the greatest contributor to
inefficiency of resource use and our inability to achieve greater global food security and sustainability.
More than 1.3 billion tons of edible food material are wasted annually around the world, which
represents about one third of the total food produced and is enough to feed more than one billion
people. The amount and types of food waste vary between countries where 44% of global food waste
occurs in less-developed countries during the post-harvest and processing stages of the food supply
chain, while the remaining 56% of these losses, of which 40% occur at the pre- and post-consumer
stages, are attributed to developed countries in Europe, North America, Oceania, Japan, South Korea,
and China. As a result, the United Nations (UN) has deemed food waste reduction as a global
priority and included it in the list of sustainability goals. Specifically, food waste reduction has
significant implications for several of the UN Sustainable Development Goals including: Zero hunger;
Responsible consumption and production; Climate action; Life below water; and Life on

Crises often accelerate existing trends and the COVID-19 pandemic is redefining the concept of sustainability. The COVID-19 pandemic has caused major disruptions in food supply chains and caused huge shifts in food access, food security, and food losses due to changes in food flow and distribution patterns [6]. Food supply chains are complex and most operate in a “just-in-time” mode where minor disruptions can have dramatic consequences. When employees were required to stay at home, and all businesses except those deemed essential were closed, consumer demand for food shifted from food services (e.g., restaurants, hotels, schools, and institutions) to retail grocery stores. Although ample supplies of food were available, existing food distribution networks were unable to quickly respond to these changes, which resulted in increased food waste. For example, short-term disruptions in eating habits during the early stages of the COVID-19 outbreak in Spain resulted in a 12% increase in food loss and waste. Furthermore, increased shortages of agricultural and food processing workers caused by illness or fear of becoming ill led to fruit and vegetable crops being destroyed, and closures or reduced processing capacity of animal slaughter plants. This severely restricted access for market-ready livestock and poultry and resulted in the unfortunate need to humanely euthanize and dispose of millions of animals originally destined to enter the food chain. Economic losses due to COVID-19 disruptions have been estimated to be at least USD 13.6 billion for U.S. cattle producers and USD 5 billion for U.S. pork producers, with 30% less meat available to consumers at a projected 20% increase in price. In addition to these economic losses, lack of sufficient rendering capacity for disposal of market-ready animals has required using other less desirable methods of disposal, which are detrimental to the environment and cause inefficiencies in resource use (i.e., land, water, nitrogen, phosphorus, labor) while increasing biosecurity risks.

As a result of the COVID-19 pandemic, researchers have proposed rethinking and
redefining sustainability as the intersection of the economy, environment, society, and human health.
Furthermore, a more holistic approach that includes climate, economics, and nutrition is needed to
improve food supply chain efficiency by reducing food loss and improving waste management of
food supply chains adversely affected by changes in consumption patterns caused by pandemics.
In fact, the European Union has already indicated plans to use knowledge gained from COVID-19
impacts on food supply chains to revise the Farm to Fork subsection of the Green Deal reforms.
Now, more than ever before, it is time for researchers and food sector experts to accelerate efforts for
developing more sustainable and modern food systems by reducing the cost of food waste recovery
and reutilization in the food chain. However, a very important component of food loss that has
not been considered in all of these proposals, which also has dramatic effects on food security and
sustainability, are mortalities caused by animal disease epidemics.

The African Swine Fever epidemic in China caused estimated losses of 220 to 300 million pigs that
were originally destined for the food chain in 2019. This enormous number of pigs represents
25–35% of the total world pig population that died or were depopulated from infected farms.
Because of the lack of infrastructure to manage the disposition of millions of pigs, the capabilities to
recover nutrients from carcasses through rendering was not possible, and carcass burial and disposal
in landfills were used at great environmental costs and biosecurity risks. In addition, highly
pathogenic avian influenza outbreaks in many countries around the world have resulted in losses of
millions of chickens due to mortality and depopulation. Unfortunately, the likelihood of future
disruptions in global food animal production caused by animal disease epidemics is increasing because
of increased global trade and travel, urbanization, exploitation of natural resources, and changes in
land use.

These unprecedented food losses due to disruptions in global food supply chains have created an
urgent need to reevaluate the intertwining of resource recovery, environmental impacts, and biosafety
of various food waste streams and animal carcasses to achieve the greatest value. This is essential
because animal-derived foods provide about one third of total human protein consumption, but
their production requires about 75% of arable land and 35% of grain resources, while contributing
about 14.5% to total greenhouse gas emissions. Reimagining recovery of nutrients from food
waste and animal carcasses, and subsequent recycling of these valuable nutrients into animal feed,
can provide tremendous opportunities to use less arable land and rely less on global grain supplies to
produce meat, milk, and eggs, while reducing animal agriculture’s contribution to greenhouse gas

Unfortunately, food waste has become an even bigger problem in many countries because of supply chain disruptions during the COVID-19 pandemic and African Swine Fever epidemic. Although Japan and South Korea have been leaders in recycling food waste into animal feed, countries that produce much greater amounts of food waste, such as the United States and the European Union, have lagged far behind. Concerns about the risk of transmission of bacteria, prions, parasites, and viruses have been the main obstacles limiting the recycling of food waste streams containing animal-derived tissues into animal feed and have led to government regulations restricting this practice in the U.S. and EU.
However, adequate thermal processing is effective for inactivating all biological agents of concern, perhaps except for prions from infected ruminant tissues. The tremendous opportunity for nitrogen and phosphorus resource recovery along with several other environmental benefits from recycling food waste streams and rendered animal by-products into animal feed have not been fully appreciated for their substantial contribution toward solving our climate crisis.

Therefore, the purpose of this review is to summarize the current knowledge of the benefits and limitations of recycling various pre-harvest to post-harvest food animal-derived waste sources, as well as retail to post-consumer food waste sources, into animal feeds to achieve greater food security and sustainability during an era of escalating food losses throughout the entire food supply chain. In next month’s Swine & U, we will examine further the options for maximizing resource recovery and value of waste streams when dealing with food waste disposal.

Dr. Jerry Shurson is a Professor of swine nutrition in the University of Minnesota Department of Animal Science and can be reached at

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