Can Pigs Help Reduce Food Waste?

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 snack-eating superpower 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 unsuitable for human consumption? Turning them into feed for farm animals might just be the most environmentally friendly thing to do. 

Is it okay for animals to eat food that we waste?

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 worldwide.² These products are usually of single origin and are not mixed with foods that may be unsafe 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 strong contenders to turn these scraps into a meal. Among these, pigs are especially suited to eating food leftovers.³

What do pigs eat?

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 descendants 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

Pig food from food waste: are there any risks involved?

The robustness of pigs does not mean they are immune to diseases 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 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 severe 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.

Pig nutrition & food waste 

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 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 

So, what’s the best way forward?

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 significantly 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, using less land for livestock farming, reducing carbon emissions related to producing and transporting animal feed, and even slowing 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. Today, Japan is a pioneer in converting food waste into pig feed.³ A little over 50% of the 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