Gene-edited livestock could be a boon to farmers in developing countries

WASHINGTON, D.C.—Raising livestock is a vital source of income in developing countries. But these nations lack sophisticated breeding programs, so their cows and chickens don’t make as much milk, eggs, or meat as their counterparts in advanced economies. And because most farmers in developing countries have just a few animals, they risk losing all or most of their livelihood if a disease wipes out their livestock.

The Centre for Tropical Livestock Genetics and Health—based in Edinburgh and Nairobi—aims to help farmers in developing countries grow hardier and more productive animals with a little help from modern gene-editing techniques. Researchers can make tiny changes to DNA that mimic traditional breeding, but faster, and they can help identify which animals might be best for breeding.

Biologist Appolinaire Djikeng heads the center, which works with scientists and policymakers in developing countries. He spoke about the center at the annual meeting here of AAAS (which publishes Science ) earlier this month and sat down with Science to chat about his work. This interview has been edited for clarity and length.

Q: How did you become interested in this work?

A: I was born in the western part of Cameroon. If it wasn’t for livestock, I wouldn’t have received any education. My school fees were paid always by sales from livestock. I studied genomics during my Ph.D. and increasingly realized the power of what it could do. I was always thinking about what I could do back in the environment I came from, either improving [the] health of people, animals, and things like that.

Q: What challenges do livestock farmers in developing countries face?

A: Productivity is really, really low for a range of reasons. If you look at milk production, for instance, on average, dairy cattle in sub-Saharan Africa in the best-case scenarios are producing five times less than what you would get in temperate climates [i.e. places with advanced economies]. In advanced economies, what has really helped is very structured and long-term breeding programs. Animals are continuously monitored for inbreeding and stuff like that. In most of sub-Saharan Africa, you don’t have those breeding programs in place. So it makes it very difficult for you to track genetic material over several generations.

More than 50 years ago, the easiest thing was just to import some animals from temperate climates. But because of the climate, it didn’t work. The animal is really not adapted to the hotter environment.

Another option was breeding tropical livestock with these temperate animals. But you’re dependent on luck because you didn’t even know what genes to look for.

Q: How do you use genetic tools to improve livestock?

A: Our work is focusing on looking at improving livestock productivity and focusing on a number of traits. That trait could be fast growth, it could be resistance to disease, it could be productivity, like milk production, egg production, and quality of the meat.

For less complex traits, you can identify a single gene or a single variation in DNA that confers that trait. But for other traits, it’s going to be less obvious. It could be an association, a combination of many, many genes, or a very large genomic region. If we get a single gene or a single variant which is linked to an important trait, then you can do genome editing.

But in cases where it is a group of genes that are conferring that trait, you’re limited. You cannot do genome editing. What you’re left to do is to select animals that have that genomic region and enter conventional breeding.

Q: How does your work help farmers with their breeding?

A: If we have an animal that is very suitable for [breeding], we can do a genetic profile for that animal to be easily identifiable. You document it not only visually, but also based on the genome and the genetic profile.

And what we rely on is really reproductive technologies. Let’s say you have a sire that farmers agree is the best sire. You can quickly multiply using artificial insemination for most farmers to have the same animal in the community.

Q: How have you engaged with policymakers?

A: We realized that the best way to engage them was to invite them to see what’s happening. For example, the official opening of the facilities in Nairobi, Kenya, was with the former president of Kenya, Mwai Kibaki. When he came to visit, one lady from our program talked to him about the work that they’re doing to address a disease of sweet potato. And the president was really impressed. It wasn’t somebody from a different country telling him what was happening. That was really building the trust.

I think that that was the beginning. It got in the press, and everybody talked about it. Then we started hosting groups of politicians from the Parliament who came to learn, and they asked questions. I think that’s a very good way of engaging. When you engage people at that level, there is trust, and they actually come to you with problems.

I go to my village and tell people about it, they’ll trust me because their problems are my problems. I’m not going to tell them to do something that I wouldn’t do myself.