Despite the growing number of vegans and vegetarians in the world, the global demand for meat is still rising as the world population grows. If present trends continue, humans will consume almost double the amount of meat in 2050 compared to 2007. But, there is also an increased demand for the “ethical treatment” of animals that we use for food.

We generally see ethical treatment as good for the animals, and many producers also recognize that it benefits their bottom line. When humans treat animals poorly, it often results in bruised or darkened meat, which producers can’t sell and so must discard it. This costs the industry billions of dollars per year. What’s more, producers are legally supposed to adhere to animal welfare legislation to avoid hefty fines and other penalties. Finally, studies have shown that consumers are willing to pay more for ethically-produced food, which has led some businesses to create their own welfare codes—some of which are more stringent than government codes and others less so.

With all this in mind, the questions become, how do we judge facilities’ adherence to welfare standards, and do they actually result in the better treatment of animals? In this review, the authors sought to evaluate some common standards and to find out how well they do their job.

One classic welfare standard is the Five Freedoms, which appeared in 1965. They are as follows: freedom from hunger and thirst; freedom from discomfort; freedom from pain, injury, and disease; freedom to express normal behavior; and freedom from fear and distress. While the Five Freedoms framework is a good start, it is incomplete. The criteria are relatively generic, and several of them overlap. Also, finding out the level of each freedom is difficult in a commercial slaughterhouse setting.

The Welfare Quality Project refined the Five Freedoms in 2008, and uses four main criteria: good feeding, good housing, good health, and appropriate behavior. Each main category splits into subcategories, resulting in 12 overall measurements. The Five Freedoms and Welfare Quality Project have four main areas of overlap: nutrition, environment, health, and behavior. But, neither of these frameworks consider the subjective mental experiences of animals; they mostly focus on any outward expressions of suffering or contentment.

The U.S. Department of Agriculture’s current evaluation of animal welfare at slaughter uses five measures, all of which relate to the physical health of animals and any outward expressions of suffering. But, these may not paint a full picture. For example, in a plant where staff struck 90% of cattle with an electric prod, only 32% made any kind of vocalization (one of the measures) in response to this. This does not mean that they found the prodding pleasant—even just intuitively, we all know it’s possible to suffer without expressing it vocally. What’s more, the guideline makes no differentiation between positive and negative vocalizations, nor considers the severity of the vocalization.

Part of the difficulty of creating these frameworks—and implementing them—stems from the fact that commercial slaughterhouses process thousands of cows each day. There simply isn’t enough money to enable more thorough, holistic welfare inspections. So far, researchers have only tested new frameworks in smaller slaughterhouses that process under one thousand cows per week.

Nevertheless, there are some intriguing developments, such as QBA—qualitative behavioral assessment. In an Australian program, 15 observers described some slaughter-bound cows in their own words. The researchers found that the observers’ descriptions were generally in-line with biological assessments. And most observers agreed, suggesting such descriptions may be a useful noninvasive method of welfare evaluation. Some programs have developed weighted scores, giving more value to criteria that are a stronger prediction of poor welfare. But, these weighted scores still rely on behavior alone, which may not fully capture the suffering of animals.

In their conclusion, the authors recognize the need for a simple, comprehensive welfare assessment that draws from the strengths of existing methods. Such an assessment needs to consider behavioral, biological, and subjective criteria. Slaughterhouse personnel should also be able to carry out the assessments, not just visiting experts. This may sound like a tall order, and it is—that’s part of the problem.

If we can’t carry out proper animal welfare inspections because of a lack of money or time, that’s a sign that it’s impossible to ethically fulfill demand. The challenges in the future will be to curb the demand for animal products and ensure that welfare certifications are more than just rubber stamps. Consumers have to be willing to either eat less meat, to pay more for it, or to stop caring about animal welfare. The easiest option for most people is the last one, and that’s where animal advocates need to step in. Widespread apathy toward animal welfare allows brutality, but an engaged and active consumer base can help to fight it. Changing the method of supply requires a change in demand, which ultimately requires consumers to change their behavior.