Why Meat Eats Resources

In articles about water use and quality, footprints


This is the second of three posts about the possible limits to global meat production as resources are strained by growing populations, prosperity and meat consumption. (Part 1 and Part 3.)

How much meat do you get with the same amount of feed?

Surprise and disbelief. That’s what often follows when people learn about the large water footprint of many meat products.

Common responses include: “Really?” “That can’t be right.” “That’s ridiculous.”

Shock is reasonable after discovering that the global average water footprint – or the total amount of water needed – to produce one pound of beef is 1,799 gallons of water; one pound of pork takes 576 gallons of water. As a comparison, the water footprint of soybeans is 216 gallons; corn is 108 gallons. (Compare more products here [US standard] and here [metric].)

The large water footprints for beef, pork and other meats indicate the large volumes of water used for their production. They also suggest a great use of resources beyond water. The question then becomes, why is raising livestock and poultry for meat so resource-intensive?

The answer is mainly based on the food that livestock eat. Here, the water footprint concept can provide some insight. What the water footprint reveals is the magnitude of water “hidden” in meat as a tally of all the water consumed at the various steps during production. Better understanding meat’s resource intensity necessitates a closer look at two crucial factors.

Feed Conversion Ratio

The efficiency with which an animal turns its food into body mass is known as a feed conversion ratio (FCR).  This applies identical units to both feed and meat; the feed:meat ratio). The range of FCRs is based on the type of animal, and according to Dr. Robert Lawrence of Johns Hopkins University, the ratios are approximately:

  • Beef: 7:1
  • Pork: 5:1
  • Poultry: 2.5:1

The larger the animal, the larger the percentage of the animal’s body mass is inedible material like bone, skin and tissue. This is why beef conversion ratios are the highest. It is also why it takes exponentially less water and energy inputs to produce grains, beans and vegetables than meat.

To be clear, raising a beef cow takes more resources because a typical beef cow in the US eats thousands of pounds of the corn and soybeans during its lifetime. Of course, the cultivation of field crops that are eventually fed to beef cattle require huge amounts of water, fertilizers, fuel to power farm machinery, land for farm fields and so forth. It all adds up.

Food Production Scale

The second reason for meat production’s great resource intensity is due to its immense scale. Globally, there is a projected “food animal” population of over 20 billion, more than twice that of the current seven billion humans the planet carries, with the animal count expected to rise along with human population growth. The animal production system expanding rapidly around the world is the industrialized concentrated animal feeding operation (CAFOs) model, the so-called “conventional” (and extremely problematic)  American system developed in over the last 50 years or so. CAFOs are more efficient strictly in terms of more animals produced, faster animal growth and shorter meat-to-market times because huge numbers of animals are combined into one facility where they are fed grains (and growth promoters) before being butchered. The enormous quantity of feed given to large populations of livestock, poultry and even fish – consisting primarily of corn, soy and other grains – can also exact a heavy toll in terms of resources and external pollution because of the industrial production of these crops.

Even though there are perceived economic efficiency gains due to scales of production, the sheer size of these operations – including industrially produced crops and their overreliance on fossil fuels and fertilizers – swamps those gains entirely in terms of real, absolute resource-use and pollution

Rather than represent meat production in the abstract, this post brings forward the reality that meat eaten by many people every day has a concrete effect on resource use. Not only is meat resource-intensive, but the system of production, as in the CAFO model, also carries substantial environmental and human health problems rarely accounted for in the race to meet the demand for meat.

Why do the resources needed to produce meat matter?

In the end, people need to eat, regardless of resource availability, but, as the world gets smaller, owing to population growth, higher incomes and wider adoption of technology, there is a greater strain on resources–a process in which meat is implicated. That’s why revealing the virtual water hidden in meat and explaining its resource-intensity matters; acknowledging the potential problems and limits can lay the groundwork for sensible, sustainable ways forward. It also suggests that, as feeding the world is a primary objective, humanity might be wise to alter our current trajectory of evermore meat produced industrially at any cost.

Originally published at GRACE’s former blog Ecocentric by Kai Olson-Sawyer on 10.29.2013
Image: Kirsten Carr on Unsplash.