SLU: Sustainable Agricultural Production and Food Security

High milk yields in a harsh climate: Is it all about the genes?

Photo by ILRI/Stevie Mannvia Flickr CC BY-NC-SA 2.0

Droughts, heat, erratic rainfall and floods can leave cows, sheep and goats with little to graze on. Changing climate will affect production of feed for livestock too. Harsh and extreme weather conditions can also reduce reproductive ability and undermine health of animals.

Another big concern is water. Livestock, and especially the dairy sector, need a lot of water; Right now, it is estimated to use nearly 30% of all freshwater in agriculture.

There are studies that predict that climate change will make diseases spread faster, leading to higher mortality among animals. This issue also has a human dimension because several of the animal diseases are zoonosis, meaning they can spread from animals to humans.  

Clearly, climate change is a big concern for the global meat and dairy industry, but we should not forget that in many low-income countries, like for instance in sub-Saharan Africa, for many people livestock rearing is a way of life. The animals provide food; manure for fuel, fertilizer and building materials; wool and hides; and draught power.

Livestock are both economically and culturally important, and in areas not suited for cultivation, they convert low-value materials such as grass and weeds into nutritious food for people. Pastoralist communities are perhaps the brightest example of livestock based livelihoods, and for them the effects of climate change can be detrimental.

But so how can we solve this? Or at least make the risks lower? Can we perhaps breed a climate proof sheep or cow that would also have good productivity?

Appears that many indigenous breeds already have climate proof genes. However, crossing them with exotic breeds diminishes their drought and disease resistance.

Recently published policy brief “Use of Livestock Resources for Food Security in the Light of Climate Change”, made through SIANI collaboration with SLU, considers ways to enhance livestock productivity and management by improving livestock breeding. The authors place sustainable use of genetic resources at the centre of their approach, but also pay attention to the social surroundings of livestock rearing, like the role of gender, for example.

Many indigenous breeds are adapted to survive in harsh environments, but they are often seen as less productive and less competitive. To boost productivity, local breeds are often crossed with higher-yielding exotic breeds. This works in the short run, but over time, tends to fail because in the end exotic breeds don’t suit to local conditions and require feed and management infrastructure that is not necessarily accessible in every village.

That is why, according to Jan Philipsson from the Department of Animal Breeding and Genetics at SLU, conserving local breeds by genetic selection can step up their competitive advantage and increase their productivity. And for doing so, breeding programs need to be long-sighted.

He explains this on the example of Red Massai sheep, indigenous to East Africa, and Dorper sheep, indigenous to South Africa. Red Massai is well-known for its resistance to diseases and tolerance to drought. The breeds have been crossed to increase meat production.

“The genetic potential of Red Massai sheep is largely unexploited. And it is superior in harsh environments. Our studies show crossing Dorper and Red Massai leads to high productivity if the climate is good, but makes no difference in harsh conditions. Moreover, when the droughts come, the crosses and pure Dorpers show to be less resilient comparing to Red Massai. And if all population of Red Massai is crossed, the breed will be extinct. Thus, it is important to keep Red Massai breed pure because it is well suited for long term sustainable use.”

Instead of continued cross-breeding the researchers offer synthetic breeding as an alternative. This type of selection provides better opportunities to incorporate desired genes while conserving genes important for adaptation to a specific environment.

“Synthetic means that it has been “constructed” from crossing two or more breeds. The best crossbred animals are then selected and adapted to the environment where they produce. This way the best genes of the crossbred population, independent of the breed origin, are transmitted to the following generations. So, the synthetic breed will be superior to the initial pure breeds used for crossbreeding”, - explains Jan Philipsson.  

Yet, none of this would work unless there is an effective recording and monitoring system in place. Such system should be based on factual information about performance and ancestry of the individual animals. Recording systems like this have proven to be effective in many animal improvement programmes worldwide, independent of species.

So, livestock productivity can be enhanced with better breeding. In fact, we already have those climate proof breeds at our disposal, and we must cherish their genes, protecting them from extinction.

However, like with most of the climate change related issues, it is not only about the hardware. Implementing breeding programmes aimed at high livestock productivity under the climate change will require better infrastructure and capacity development at all levels. It will also require policies that would allow sharing of genetic resources across borders. Special attention should be paid to training of women, who usually take care of livestock in many rural households across sub-Saharan Africa; It is they who can lead future livestock based enterprises.

So, it is not all about the genes, but breeding plays an important role for sustainability of our livestock systems in the face of climate change.