Tinder for cows

Planning which animals to pair during breeding is important, both to develop future breeding stock and to effectively avoid unnecessary inbreeding as well as defects and deformities. Breeding planning is not a new concept in itself; it has been carried out using various approaches throughout history, from analyzing pedigrees to today’s advanced technology.

But how do you plan for successful breeding? And how do you really know which bull is right for which cow?

For more than fifteen years, it has been possible to perform DNA testing on cows. A tissue sample is collected during the mandatory ear tagging process. Analysis of this sample can provide information about the animal’s genetic profile. However, DNA testing has not provided a complete answer to the question of which animals should then be matched—until now, when the process has been taken a step further.

Tinder for cows

What Christian and his team have managed to do is simply to develop a mating program with a clear goal: the right bull for the right cow. Using a database of DNA information collected from many thousands of cows, they have been able to develop a program that simulates matings. A program that has come to be known colloquially as “Tinder for cows.”

Mating according to the new breeding program still offers no guarantee that the calf will turn out exactly as expected, but the results are proving to be much closer to expectations than previous predictions. This is because DNA information reveals which traits each animal carries and is therefore capable of passing on—traits that can indicate both how well a cow will be able to produce milk and her potential to stay healthy.

The vast majority of animals likely carry defects—both known and unknown—but when we can ensure that neither parent carries the same known defect during mating, the risk of birth defects disappears. It is also possible to more reliably identify which calves will become the best milkers by examining their DNA.

Using this method, he hopes that farmers can save time, money, and reduce the animals' suffering—by avoiding unsuccessful matings as much as possible.

Take your pick from a variety of features

However, another gene has also been studied in this project: whether or not a calf will have horns. Horns are natural in many animals, including cows, but they also pose a significant risk of injury both among the animals themselves and to the people who handle them. Currently, most calves are therefore dehorned. Christian’s team investigated whether it was possible to effectively increase the proportion of calves born hornless through the breeding program without sacrificing too much in other traits, and it turned out to be possible.

To develop a super cow

But selection is not just about a cow's milk production; it is also about its potential for health and well-being.

The future: Energy-efficient cows with reduced methane emissions

Now that the study is complete, Christian Bengtsson hopes that the “Tinder” program can be implemented by farmers throughout Sweden. But his dreams for the future extend even further. There are, in fact, other aspects to simulating matings and “selecting” which genes are desirable for breeding—namely, the environment.

Both the production of cattle feed and the methane gases that cattle belch out are harmful to the environment, and it would be good to minimize them—for the sake of the climate.

Is that possible? Yes.

That said, it’s not quite as simple as farmers being able to breed exclusively from the optimal animals going forward. Breeding efforts must also take a long-term perspective, and to secure the future, genetic variation is needed—that is, a large number of animals that are distantly related—so that there is a pool to choose from, both now and in the future.

You can now read the full account of “Tinder for Cows” in Christian Bengtsson’s doctoral dissertation via the link further down the page. Next up are new projects, one of which is linked to SLU and can therefore also be followed in the future.