Animal research is moving rapidly in two, divergent directions. Research on animal cognition, behavior, and welfare is teaching us that many animal species have complex cognitive and emotional lives and needs. Such insights reasonably increase our empathy for and insight into species other than our own. At the same time, new gene editing technologies are allowing scientists to design animals in ways that maximize their economic value as food sources. These technologies include programmable nuclease-based genome editing technologies, such as zinc-finger nucleases, transcription activator-like effector nucleases (TALENs), and the CRISPR/cas9 system. They permit the direct manipulation of virtually any gene of a living organism more easily, cheaply, and accurately than has ever been possible before. In the last five years, these technologies have been used to edit the germline of more than 300 pigs, cattle, sheep, and goats. In June 2015, a team of scientists from South Korea announced the creation of super-muscly pigs using the single-gene editing technology TALENs. Whereas the debates on the ethical and social aspects of genome editing of human embryos and crops have triggered public, political, and media firestorms, genome editing in animals has received virtually no ethical scrutiny. Yet gene modification of farm animals like super-muscly pigs raises complex ethical questions about animal welfare, about who is benefiting from these technologies, and about the evolving, contradictory relationship between humans and animals. These questions have been ignored so far, but our growing awareness of the rich inner lives of many animal species makes such neglect increasingly troublesome.
The animals’ perspective
Concerns about the welfare of genetically engineered animals starts with the very process of creating them. Sperm and egg donors and surrogate mothers are normally killed if they are not “re-usable” for other purposes (such as in other animal experiments). Furthermore, animals whose modifications end up being undesirable either die because their health is severely compromised, or are killed because they are neither commercially valuable nor usable for scientific purposes. Due partly to the novelty of the methods, little data are available on the costs of new engineering techniques in terms of the total numbers of animals used, the unintended suffering created, and the effects that they are having on the phenotypes of various species. For the super-muscly pigs, the large size of the newborn piglet leads to birthing difficulties; only 13 of the 32 piglets created by the South Korean scientists survived as long as eight months, and only one survived considerably longer in a healthy state.
For sheep, goats, cattle, and pigs, genome editing techniques are used to modify primary cells, which are then transferred to the recipient mother via somatic cell nuclear transfer (cloning). This causes a range of animal welfare problems, such as very low live birth rates in some species; abnormal sizes, which render them incapable of natural movement; and respiratory and cardiac problems. Although genome editing techniques are expected to offer a more precise modification of the genome, they, too, generate many more animals than are actually used for experimentation. For example, a 2016 paper by Wenfang Tan and others in Transgenic Research surveyed the published literature and determined that out of 23,216 pig embryos, which were implanted in 112 pigs and generated 62 pregnancies, 237 pigs were born alive. Of these, 179 (76%) were properly modified or “edited,” whereas the remaining 58 were not usable for the experiments. The scientists working in the field concentrate on the 76% of the pigs born alive and properly edited, which represents a success with respect to previous technologies. However, if we go back to the number of the embryos needed, to the pigs involved in pregnancies as well as to the individuals born which do not carry the modification needed, we can easily see how evaluation of the “efficiency” of these procedures depends on whether and how one counts the lives of the animals involved at all stages of the process. Among other considerations, as noted in a 2015 paper by Goetz Laible, Jingwei Wei, and Stefan Wagner, the “high efficiency” of CRISPR/Cas9 gene editing comes at the price of unintended mutations elsewhere in the genome.
For the scientists working on animal biotechnology in agriculture, the “efficiency” of gene editing provides a path to “solutions to securing food security for a rapidly growing human population under constrains of decreasing resources and a changing world climate,” as Laible and colleagues explain. However, if we move the focus away from the perception of animals as sources of food products which need to be optimized, and instead consider the new types of costs that animals must pay for being created through these technologies, the picture becomes very different.
Threats to the animals’ welfare do not end with their creation in the lab. Pigs, like many other animals used in agriculture, are being increasingly recognized by scientists as having complex abilities and needs in both the cognitive and social domains. As sentient beings, they have what biologists and veterinarians call “ethological needs,” comprising, for example, the need to explore their surroundings and to engage in meaningful social interaction with others of their species. These needs are an innate and important part of the animals’ behavioral repertoire. For example, animal welfare researchers have shown that if sows are not permitted to build nests prior to piglet birth, welfare problems such as abnormal repetitive behavior including bar-biting (chewing the metal bars of their crates), tail-biting, head-weaving or vacuum chewing (chewing when nothing is present) appear. Farm animal suffering manifests in diseases, lesions, or injuries (sometimes linked to high stock densities or quality of flooring), due to lack of space and behavioral stimuli, malnutrition, stress during handling, isolation, transportation, and, ultimately, killing methods.
We mention these well-known signs of animal discomfort because gene-editing of pigs and other farm animals is not being developed with consideration of how it might contribute to or even exacerbate such suffering. Especially in countries with very minimal or no animal welfare regulations, increased productivity due to genetic engineering could simply lead to more inhumane breeding, raising, and slaughter of ever-greater numbers of animals. Scientists who view genetically modified (GM) animals only in terms of food production fail to take into account the ethical costs of their one-dimensional perspective. The rationale for such a narrow view is obvious—increased yields in mass production of meat directly translate to increased profitability. But who is accounting for the increased animal suffering that gene editing technologies enable? Our concern is that the value gained from the higher precision of modifications compared to selective breeding, not to mention the economic interests involved in the meat market, create a powerful disincentive to consider the welfare concerns connected to GM animals.
The global context
The ambition behind the genetic modification of pigs and other animals bred for human consumption is to increase economic productivity. Scientists developing GM animals insist that their engineered status poses no threat to the environment, but such arguments cannot address larger questions of a globally sustainable food policy.
The livestock sector accounts for 14.5% of total global greenhouse gas emissions, which is more than the entire transport sector. It is the largest global source of the greenhouse gases methane (from ruminant digestive processes) and nitrous oxide (from manure and fertilizers used in the production of animal feedstuffs). The 2011 European Nitrogen Assessment estimated that in Europe, 85% of harvested nitrogen is used to feed livestock, with only 15% feeding people directly—even as the average European Union (EU) citizen consumes 70% more protein than needed for a healthy diet. Animal production creates substantial water and land pollution and requires vast amounts of territory—an estimated 45% of the global land surface area. Meat consumption is also linked to increased health risks such as cancer, ischemic heart disease, stroke, and diabetes mellitus. A report of the United Nations Environment Program (UNEP) concludes that both human and global environmental health would benefit from a substantial diet change away from animal products on a global scale. Yet demand for meat and dairy products continues to rise worldwide, driven especially by expected rising standards of living in China, India, and Russia. According to the Organisation for Economic Co-operation and Development (OECD)/Food and Agriculture Organization (FAO) Agricultural Outlook 2015, global meat production rose by almost 20% over the last decade and is expected to further expand until 2024. Pig meat production is expected to expand by 12% and poultry by 24% relative to 2012–14. The expansion is driven, in part, by increased profitability, particularly in these two sectors. Developing countries will account for approximately 75% of the additional output. To the extent that genetic modification of livestock increases meat production, it is also likely to lead to a “rebound effect,” driving prices down and further increasing the demand for animal products—just as making roads wider or paving more parking lots tends to make traffic problems worse. Thus, economic incentives, changing demographics and dietary habits, and advances in gene editing technology are all pushing in the same direction toward increased stress on global environmental and food production systems.
Given these concerns, there is profound unresolved tension between, on the one hand, the plea by an increasing number of scientists and institutions like the OECD/FAO and the UNEP for a substantial reduction in agriculture’s adverse impact through a decrease in the use of animals for food, and, on the other hand, biotechnologists’ support for ever-enhanced forms of animals for meat and dairy production. This tension is fundamentally political in nature, yet it is also a problem of ethics and values, not only because these technologies have negative impacts on animal welfare, but also because they profoundly shape the way in which we think about animals.
The changing human-animal relationship
Increased knowledge about animal sentience, cognition, and behavior is changing the human-animal relationship. Decades of ethical debates and a tightening of animal welfare regulations in many countries around the world contributed to higher awareness of the needs of some animals—predominantly the ones we take into our homes. We increasingly attribute emotions, intelligence, needs, and even some rights to our companion animals. We usually do not kill and eat them. Our perception of farm animals, like pigs, is substantially different, of course. We only pet the ones we love and tend to forget about the ones we eat—a cognitive dissonance which to us is one of the most striking and ethically problematic features of today’s human-animal relationship. Psychological studies show, unsurprisingly, that we tend to resolve our cognitive dissonance by denying the suffering and complex cognition of the species we want to eat. Meanwhile, scientific evidence increasingly shows that farm animals share capacities like sentience and cognition with humans, thus making it increasingly difficult to grant them an exemption from moral relevance.
Although science aimed at understanding the cognitive capacities of animals gives us reason to appreciate and empathize with dogs and pigs alike, technological advances like gene editing enhance the drift of the moral status of farm animals away from living beings that have inherent value (a moral standing in themselves) to products which only have instrumental value and a market price. Gene-edited animals like super-muscly pigs are brought to life and designed to meet human desires. Scientists speak of eliminating undesired traits to enhance productivity. In the process, it may even be the case that these designed animals suffer more than their non-GM relatives because of their extreme physiological traits. They are a technological success exactly because they are optimized—for example via an increase in body mass to match their instrumental purpose—but what about their suffering?
The scientific creation of super-muscly pigs thus drives a problematic understanding of animals. It does so in times where we are increasingly aware that animals, at least sentient animals, have needs and interests themselves and objective attributes of individual welfare, and thus moral standing that is independent from their instrumental value as objects for our consumption.
As such, the application of gene editing to animals, which to some is a step forward for technology, may be a step backwards for human moral development, as it conceals and heightens conflicts and dilemmas about which a truly reflective society should be openly deliberating. The continued pursuit of our scientific capacity to engineer animals for consumption, without commensurate attention to the ethical issues at the center of global meat production is at best naive, and at worst irresponsible. Recent decades have seen significant strides in confronting the ethical challenges of our relationships with animals, progress that is supported by our increasing scientific knowledge about animal cognition and sentience. Concern for animal welfare is rising. Meanwhile, from the overuse of antibiotics to the pollution of waterways from feedlots, the environmental consequences of the global food system add another dimension of concern to the globalizing market for meat. In all, our growing understanding of the human-animal relationship suggests that we need to revise our view of sentient animals, such as pigs, to recognize that far from being merely editable genetic material and edible flesh, they are also living individuals that merit our serious moral consideration.