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Livestock and feed-food competition

We often hear that farming animals is wildly inefficient because they turn human-edible crops into meat at terrible ratios. But is that critique fair, or does it overlook agricultural realities?

Reducing the competition between animal feed and human food is one of the main priorities for future food systems development. However, this competition varies based on context and is often exaggerated. Claims that meat production requires 6-20 kg of grains per kg of meat are overstated; the true input is around 3 kg of human-edible feed. This constitutes a minor part of total feed, which is mostly inappropriate for human consumption. The largest portion of animal feed (86%) is non-edible, consisting of items like grass, leaves, crop residues, and by-products. For ruminants, an even small proportion of their diet consists of direct competition with human food. They mostly consume low-opportunity-cost feed and can deliver more high-quality protein than they require from human-edible sources. As such, they contribute to global human-edible protein as net producers.

Nonetheless, feed-food competition will remain one of the major challenges for the livestock sector, especially for monogastric animals like pigs and poultry. Also, sustainable sourcing of feed will be paramount, to reduce pressure on natural resources and halt deforestation.

This subsection contextualizes the feed-food competition as follows:

Situating the problem
Most feed is inappropriate for human consumption
Low-grade material can be upcylced into valuable nutrition
The valorization of inedible feed constitutes a sustainability asset

Situating the problem

A significant portion of global animal feed directly competes with crops that could otherwise be used for human consumption. Annually, livestock consumes 6 billion tons of feed dry matter, which includes around one-third of the global cereal supply. In the 2000s, 68% of concentrate feeds were allocated to poultry and pig production, with 32% used for ruminants. Although there is a need for further optimization, such as enhancing circularity and making better land use choices, it is important to recognize that the situation is more complex than often assumed.

Most feed is inappropriate for human consumption

Claims that one kilogram of meat requires 6-20 kilograms of grains are exaggerated. The actual input is closer to 3 kilograms of human-edible feed, while the bulk of what is fed to animals is not in competition with human food. Globally, about 86% of livestock feed comprises grass and leaves (46% of total feed), crop residues (19%), and various inedible by-products. Examples of the latter include malted barley from the beer industry, pulp from the sugar industry, and the remainders of the soybean and seed extraction industries. On average, 4 kg of inedible material is generated per kg of vegetal matter originating from crop agriculture, which can then be upcycled by livestock into nourishing foods. Even in an optimized circularity scenario, European citizens could still attain 60% (31 grams) of their current daily animal protein consumption by converting low-opportunity-cost feed, according to model predictions.

This nuance is particularly relevant for ruminants, as they rely on minimal concentrate feeds (<10%), with only around 5% of their intake consisting of grains and soybean meal on average, which may compete with human consumption. Fully grass-fed animals have even less direct competition, whereas feedlot beef represents a minority of global beef output, contrary to common misconceptions. Moreover, even grain-finished feedlot beef typically is obtained from cattle that spent around 18-24 months grazing and were only finished on grain during the last 90-180 days of their lifetime. However, due to a declining proportion of grass-fed animals, the use of crop-based animal feed globally is increasing.

Further reading (summary of the scientific literature):

Although the debate on feed-food competition is indeed worth having, claims that one kg of boneless meat requires 6-20 kg of grains are exaggerated. True input is around 3 kg of human edible feed (2.8 kg for ruminants and 3.2 kg for monogastrics) [Mottet et al. 2017], but much depends on the specificities of the system [e.g., Thomas et al. 2021; van Barneveld et al. 2023]. Moreover, human-edible input in livestock systems constitutes only a minor part of the total feed.

Worldwide, 86% of livestock feed encompasses grass and leaves (46% of total feed), crop residues (19%), and a variety of inedible by-products [Mottet et al., 2018]. Similarly, 89% of feed in the US is non-edible (mostly forage, as well as some by-products) [Rotz et al. 2019]. In an optimized 'circularity' scenario, EU citizens would already achieve 60% (31 g) of their current daily consumption of animal protein through the conversion of low-opportunity-cost feed [van Hal et al. 2019]. For comparison, current per capita protein intake in the EU has been estimated at 85 g per day, of which 50 g is coming from ASFs [Westhoek et al. 2016; see also elsewhere].

For ruminants, this point is of particular relevance, as <10% consists of concentrate feeds [Chang et al. 2019]; only 5% of the feed intake consists of grains and soybean meal on average, which can be said to be in direct competition with the human diet [Mottet et al., 2018]. While this amount is even smaller for fully grass-fed animals, it is more elevated for feedlot beef. The latter is often erroneously referred to as typical for the entire sector. In reality, it only represents of a minority of production systems and not the bulk (87-93%) of global beef output [Gerber et al. 2015; Mottet et al. 2017]. Moreover, even in the US, only 2% of cropland acres (equal to 0.3% of the US land area) is dedicated to corn grain for beef cattle feed [USDA ERS 2018]. However, as a result of a decreasing proportion of grass-fed animals, the global use of crop-based animal feed is increasing. That being said, feedlots also increasingly make use of locally available by-products (spent grain from bio-alcohol, feed-grade grain and cottonseed) [CSIRO 2022].

Low-grade material can be upcylced into valuable nutrition

Conventional assessments of the overall benefits of animal farming often overlook the fact that livestock can convert less valuable protein sources into nutrient-rich foods. Criticisms labelling animal-sourced foods as 'inefficient' due to providing only a small portion (around 15%) of calories and a fraction of total protein in human diets underestimate true human nutritional requirements. These critiques tend to overly emphasize calorie and quantity metrics, rather than considering the broader need for essential nutrition on a global scale. For example, ruminants should be recognized as positive contributors to the production of protein for human consumption. In reality, they require less protein from human-edible feed (0.6 kg) than what they ultimately provide as one kg of high-quality, human-edible protein. This highlights their potential to enhance nutritional sustainability worldwide with considerable efficiency, despite claims to the contrary.

Further reading (summary of the scientific literature):

In conventional assessments of the net cost benefit of animal husbandry, it is usually not factored in that livestock is able to upcycle low-biological-value protein foods that are less palatable into nutrient-dense foods [Smith et al. 2013; van Hal et al. 2019]. The statement that ASFs are 'inefficient foods', because they supply only 13-18% of calories and a quarter of total protein in the human diet [Smith et al. 2013; Mottet et al. 2017], severely underestimate the true nutritional needs of human populations. Such approaches excessively focus on calories or quantities of food, rather than on the global need for adequate essential nutrition [see elsewhere], which is facilitated by ASFs.

Ruminants, for instance, should be considered as net contributors to the production of human-edible protein worldwide. As a matter of fact, they need less protein from human-edible feed (0.6 kg) than what they eventually deliver as one kg of human-edible, high-quality protein [Mottet et al. 2017, 2018; FAO 2018]. A detailed analysis is available for French dairy ruminants, where better efficiencies were obtained using concentrates or by-products that are poorly digested by humans [Rouillé et al. 2023]. For beef, it has been estimated that Australian grain-fed production systems contribute almost twice the human-edible protein they consume. Typically, such cattle spend most of their life on grass followed by 90-150 days on grain. For, fully grass-fed systems, this ratio was even estimated at 1600 times [Thomas et al. 2021; CSIRO 2022].

Even monogastrics can be net protein contributors, provided that use if made of waste streams, co-products, and human-inedible feedstuffs. This has been demonstrated for intensive Australian pig systems, generating more than three times the human-edible protein it consumes in the process (net protein contribution of 3.26) [van Barneveld et al. 2023].

Replacing food-competing feedstuff that account for 15% of total feed use (cereals, whole fish, vegetable oils, and pulses) with food system by-products and residues, while taking into account the nutritional requirements of food-producing animals (incl. farmed aquatic species), could increase the caloric and protein supply by 13% and 15%, respectively [Sandström et al. 2022].

Explanatory video 💬 Windisch 2022

The role of grasslands and nutrient circularity in animal agriculture

The valorization of inedible feed constitutes a sustainability asset

Livestock do not only convert by-products (crop residues, food processing wastes, and other organic materials) into valuable nutrition, but also prevent them from becoming waste, which could contribute to environmental pollution or require costly disposal processes. Ruminants, in particular, offer unique sustainability benefits due to their specialized digestive systems, which allows them to consume feeds that monogastric animals (like pigs and chickens) cannot digest as effectively. Furthermore, by grazing on pastures and grasslands, ruminants help maintain the health and productivity of these ecosystems. Grazing contributes to biodiversity, prevents the overgrowth of invasive plant species, and promotes soil health through nutrient cycling and reduced soil compaction. Additionally, well-managed grazing systems can improve carbon sequestration in soils, making them a valuable tool in the fight against climate change [see also elsewhere]. By integrating livestock systems with crop production and other industries, agricultural practices can become more circular and resource-efficient, reducing waste, minimizing environmental impact, and improving the resilience of food systems.

The role of grasslands and nutrient circularity in animal agriculture

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