Can Pigs Help Reduce Food Waste?

Originally published on in September 2020.

Pigs are nature’s ultimate recycling heroes. What is considered inedible by most other animals is often a scrumptious meal for pigs. After following some safety precautions, this superpower of theirs can be used to reduce the amount of food that ends up as waste.

Around 30% of all food produced in the world ends up either getting lost in production, or as food waste in supermarkets or homes. When food products are thrown away, it’s not only food that is being wasted but also the land, labour, water, and nutrients that were invested in growing it. A more sustainable way to manage food scraps is to keep them in the food supply chain instead of sending them to a landfill or incinerating them.1 

But what do we do with products that have been declared as unsuitable for human consumption? Turning them into feed for farm animals might just be the most environmentally friendly thing to do. 


Just because food isn’t suitable for human consumption, it doesn’t automatically disqualify it from being safe and nutritious for other animals. Around 86% of all livestock feed is estimated to be unsuitable for human consumption anyway.2 By-products from agriculture such as sugar cane tops and banana leaves, along with by-products from food processing such as oilseed cakes are widely consumed by livestock all around the world.2 These products are usually of single origin and are not mixed with foods that may not be safe for animals to consume. 

Surplus food that comes from households, restaurants, or even supermarkets may contain a mixture of several different foods, making it a challenge to recover usable products. Despite this, some omnivorous livestock such as poultry, farmed fish, and pigs make for strong contenders to turn these scraps into a meal. Among these, pigs are especially suited to eat food leftovers.3


In comparison to other farmed animals, pigs have evolved to digest a more diverse range of food processing by-products and consumer leftovers.4,5 Today’s domesticated pigs are descendant of wild boars which foraged for food near human settlements.3 Throughout history, several cultures have domesticated pigs for recycling household waste. Pigs’ digestive systems have therefore developed to cope with nearly anything; from vegetable scraps to animal viscera.6,7


The robustness of pigs does not mean that they are immune to diseases that can be transmitted via food. Domestic pigs today are a result of breeding practices that have traded the sturdiness of wild boars for faster growth and better feed conversion ratios.3 Besides, food waste today is as complex as our food system itself. It is no longer a benign mix of peels and trimmings that come from traceable origins. 

However, experts agree that it is possible to produce safe and nutritious feed for pigs from swill that has undergone heat treatment and acidification.3 This treatment is an essential step in killing any pathogens that might be present in the food. The serious damage caused by neglecting this step was seen during the 2001 Foot and Mouth Disease outbreak in Europe which is estimated to have cost up to €12 billion in damages.8 It is now known that this viral disease outbreak occurred after certain farmers in the UK illegally fed food waste to pigs without treating it first.3 Other diseases that affect livestock such as the African Swine Fever and the Mad Cow Disease are similarly known to have spread through contaminated feed. Because of this, the feeding of food waste to farm animals is heavily restricted in the EU.


Next to safety, another aspect to consider while feeding food waste to pigs is whether such a diet meets their nutritional requirements. Food-waste-turned-swill is often not a complete source of nutrition for pigs. This is especially true for today’s fast-growing pigs that have been bred for the mainstream pig industry. However, there are some strategies that can be used to overcome this. Farms that feed pigs with food waste must source surplus food from a wide variety of food businesses to find enough consistency in nutrients.3 Swill is also often blended with conventional feed ingredients such as wheat middlings or spent brewers’ grains before feeding it to the pigs.3 This blending is monitored by trained animal nutritionists who first separate surplus food into nutritional categories and adjust the final feed based on the pigs’ dietary needs.3 


Despite the risk, the idea of recycling food waste by converting it to pig feed is still worth considering. In Europe, 88 million tonnes of food leaves supply chains as waste every year.9 Of this, at least 14 million tonnes can be recycled into feed for pigs if the current legislation is changed to ensure appropriate treatment,3 which could in turn lower methane emissions from food waste. 

Next to reducing food waste, it would have several other benefits, including allowing farmers to spend less buying animal feed, use less land for livestock farming, reduce carbon emissions related to producing and transporting animal feed, and even slow the rate of deforestation caused by soy farming for use in animal feed.3 If European countries reduced animal feed imports, it would also make certain agricultural commodities more affordable for the rest of the world, potentially improving global food security.3 

In some parts of the world, such a system is already thriving. Japan today is a pioneer when it comes to converting food waste into pig feed.3 A little over 50% of surplus from the Japanese food industry is now used as livestock feed thanks to adequate policies and a certification system.10 The ‘eco-feed’ industry collects food surplus that would have been thrown away by catering businesses, supermarkets, and food manufacturers. This waste is then transported to well-regulated treatment plants where it is treated to remove any pathogens. This end product is an eco-friendly feed that costs half of what conventional feed does.11 Meat products derived from pigs that are raised on eco-feed are considered to be of premium quality by Japanese consumers because of their environmental credentials.12 


  1. Papargyropoulou et al. (2014). “The food waste hierarchy as a framework for the management of food surplus and food waste.” Accessed 02 July 2020.
  2. Mottet et al. (2017). “Livestock: On our plates or eating at our table? A new analysis of the feed/food debate.” Accessed July 04 2020.
  3. Luyckx et al. (2019). “Technical guidelines animal feed: The safety, environmental and economic aspects of feeding treated surplus food to omnivorous livestock.”
  4. McDonald et al. “Animal Nutrition. 7th ed.” Accessed 01 July 2020.
  5. Van Hal, O et al. 2019. “Upcycling Food Leftovers and Grass Resources through Livestock: Impact of Livestock System and Productivity”. Accessed 05 July 2020.
  6. Nemeth (1995). “On Pigs in Subsistence Agriculture”. Accessed 06 July 2020.
  7. Sauer (1972).” Seeds, Spades, Hearths, and Herds: The Domestication of Animals and Foodstuffs”. Accessed 02 July 2020.
  8. “Preventing Foot and Mouth Disease in the European Union.’ European Food Safety Authority. Accessed 02 July 2020.
  9. “Food Waste”. European Commission. Accessed 04 July 2020.
  10. “Livestock Solutions for Climate Change”. Food and Agriculture Organisation of the United Nations. Accessed 06 July 2020.
  11. Takahashi et al.(2012). “Effects of Feeding Level of Eco-Feed Mainly Composed of Bread from Box Lunch Factory on Pig Performance, Carcass Characteristics and Pork Quality. Accessed 04 July 2020.
  12. Kurishima et al. (2011). “The Effect of CO2 Information Labelling for the Pork Produced with Feed Made from Food Residuals”. Accessed 06 July 2020.

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