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What do 'planetary health' and veterinary medicine have to do with each other? Everything, argued Professor of Farm Animal Health Arjan Stegeman recently during the annual congress of the  (website in Dutch). "The future of livestock farming lies in the hands of people who take both animals and the planet seriously."

Stegeman gave his presentation in the old Anatomy Building in Utrecht, the place where veterinary medicine was taught until the Faculty moved to the Utrecht Science Park in 1984. Since then, much has changed. It has become even clearer than before that the health of humans, animals, and the environment are interconnected. Nonetheless, our focus is still often too much on humans, according to Stegeman, "An animal is mainly seen as a risk on four legs or with two wings... for humans."

30 billion chickens

One of the driving forces, according to Stegeman, is the enormous increase in the number of animals kept on the planet. This is a trend that, according to Rabobank figures, continues unabated. Since 1961, the number of chickens worldwide has grown from about 5 to about 30 billion. The number of pigs increased from 400 million to over 900 million, and cattle from 900 million to about 1.6 billion. This has led to the fact that of the total biomass of all birds on earth, 70 percent is now poultry. For mammals, the distribution is: 60 percent livestock and 36 percent humans. All wild mammals account for only 4 percent of the biomass.

We have forgotten the planet and the animals, even as veterinarians

If we want to tackle major problems such as the rise of zoonotic infectious diseases, we need to understand and address the driving forces behind them, Stegeman argued. "We need to move from one health to planetary health."

The fact that many animals live close together in livestock farming is one of the drivers of the rise of (zoonotic) infectious diseases. Other factors include changing land use, climate change, and the large number of movements of livestock and people. Stegeman gave a dozen examples of infectious diseases that as a result cause major problems. It is not only about well-known infectious diseases such as corona, but also lesser-known ones, such as African swine fever.

Disastrous

African swine fever is an infection of the warthog that is spread by ticks. This has been going on for centuries without major problems until domesticated pigs were introduced. They also turned out to be susceptible to the ticks. In fact, they became deadly ill from them and could infect each other. In 2007, the virus was introduced to Georgia, presumably via food waste by boat from Southern Africa. It then ended up in European wild boars, where the virus adapted to a new species.

In 2018, there was a first outbreak in China. Stegeman: "You then see a sharp dip in the graph with the increase in pigs on earth. I mention this to indicate how disastrous something like this is. It involved many millions of animals."

Another emerging infectious disease is currently often in the news: highly pathogenic avians influenza. This was rarely found in wild birds in the past. Until 2002, only one outbreak was reported, according to Stegeman. That was in 1961 in large sterns in South Africa. In 1996, however, a new variant emerged in poultry in China: the H5N1 variant. It could spread in the rapidly growing poultry sector and was not well controlled, so the virus did not die out. The virus became endemic and adapted, for example to ducks. From 2003, it spread to other countries in Asia and to Africa. Now the virus has spread worldwide through migratory birds and has also adapted to mammals.

No one saw it coming, but at the end of 2023, a variant even emerged in dairy cattle in the US. The virus appears to multiply well in the udder epithelium. Milking therefore causes spread within dairy farms. The large scale of dairy cattle transport causes transmission between farms. Stegeman: "I looked at the most recent figures today and the US has passed the threshold of a thousand infected farms. Avian influenza started as a poultry virus, now it has become a global threat."

Taking responsibility

Stegeman: "We must also take responsibility as scientific community. First, we worked very hard to facilitate scale and productivity increases. We proudly exported efficient agriculture as the Netherlands. But we lost sight of the planet and the animals, even as veterinarians." In preventing infectious diseases, we sometimes encounter that this is at odds with what is desired for animal welfare. Think of a confinement obligation for chickens. "For scientists, it is also difficult that research funding is mainly focused on infectious diseases that are relevant to humans. It is much more difficult to research common farm-related conditions in animals, such as lameness or respiratory diseases, which are much more important from an animal welfare perspective."

How can you change this as a veterinarian? Stegeman realizes that these problems on a global scale can easily leave you despondent. Although the Netherlands has relatively many livestock, it is not significant on a global scale in absolute terms. He advocates realism. "The increase in livestock farming in the world is taking place in emerging economies, especially China. When prosperity increases in a country, you often see that meat consumption also increases. It is not easy to break that mechanism. For this, widely appreciated alternatives to animal products and international implementation of the principle of true pricing may be indispensable."

But in the meantime, the situation presents immediate challenges for veterinarians. According to Stegeman, it is important that veterinarians realize the global forces they operate in, that they learn to set boundaries well in their daily work, and that they participate in ethical and societal discussions.

We can increasingly measure animal welfare

Many veterinarians, such as the Caring Vets, are taking up this challenge. The universities of Wageningen and Utrecht are also increasingly doing so. Stegeman points to the policy contribution that scientists including himself, , and Bas Rodenburg are making to the process of achieving animal-friendly livestock farming. Six guiding principles of the Council for Animal Affairs for animal-friendly livestock farming have been translated into concrete requirements for keeping species and barn systems. The starting point is that an animal must be able to adapt to its environment to achieve a state that the animal itself experiences as positive. Stegeman: “We can increasingly measure animal welfare, looking not only at behavior but sometimes also at sounds or facial expressions. It is very important that we integrate animal welfare into the transition to sustainable agriculture. And that we ensure it also has a place in policy."

For pigs, this means, for example, providing bedding to lie in, (covered) outdoor access, truly stopping the routine tail docking, a higher weaning age of at least 6 weeks, and sows in a free-range farrowing pen. Stegeman: "Research shows this is good for welfare and for the health of the animals."

It is always about balancing the interests of animals, humans, public health, and the environment. The Faculty of Veterinary Medicine wants to better equip students for this. Therefore, the master's program has been adjusted, with more space for reflection. A new bachelor's program in Care, Health, and Society (Zorg, Gezondheid en Samenleving; ZGS) has also started, which trains students to look at health issues from very different perspectives. In research, there is also more collaboration across disciplines, for example within the strategic theme Utrecht Life Sciences, or in the field of protein transition within the Future Food program.

Stegeman concludes: "Healthy animals on a healthy planet are not possible in the current global livestock industry. We need to move towards sustainable food systems. The future of livestock farming lies in the hands of people who take both the animal and the planet seriously. And veterinarians have unique knowledge and skills to contribute. As a country, we have previously succeeded in greatly increasing productivity in livestock farming and exporting this knowledge. Let's now lead the way with innovation based on a systems approach to animal health and welfare in conjunction with the environment and humans."