The competition between animal feed and human food is a complex issue. Some feed competes with human-edible crops, with concerns about resource optimization and environmental sustainability. However, this competition varies based on context and is often exaggerated. For instance, 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. It is important to note that 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. In fact, they contribute to global human-edible protein production. 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 considerable part of global animal feed competes directly with crops that would otherwise be channelled to the human diet. Livestock consumes 6 billion tons of feed dry matter annually, including about 1/3 of the global cereal supply [Mottet et al. 2017]. In the 2000s, 68% of the concentrate feeds were used for poultry and pig production against 32% for ruminants [Chang et al. 2019]. While further optimization is needed, for instance through an enhanced focus on circularity and land use choices [van Hal et al. 2019; van Selm et al. 2022], reality is more intricate than sometimes assumed.
- Most feed is inappropriate for human consumption
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-source foods (ASFs) 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.
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].
Explanatory video 💬 Windisch 2022
- The valorization of inedible feed constitutes a sustainability asset
