Swiss researchers test ways to protect cows from heat

Swiss cows are suffering during the country’s fourth heatwave, with researchers testing ventilation, water misting, shaded pastures and breeding strategies to reduce heat stress, SRF reported.

Cows are most comfortable at temperatures between 5 and 15 degrees Celsius. Above that range, they eat less, breathe faster and produce less milk.

Modern farms use cooling systems such as fans and misting installations. At Strickhof, an agricultural competence centre in the canton of Zurich, researchers are studying how to improve these systems under practical conditions.

“We conduct applied research,” said Susanne Meese, head of animal husbandry and dairy farming at Strickhof. Researchers work with animals in the barn and test equipment that farmers could use on their own farms.

Digital sensors allow the team to monitor the cooling systems around the clock. If the cows remain active and chew their cud while lying down despite the heat, that indicates the measures are working.

The design of pastures is also becoming more important. Trees can provide natural shade, while some plant species contain tannins that may offer additional benefits. Walnut trees, for example, can also repel flies, Meese said.

Access to water is particularly important on extremely hot days. When cows remain in cooler barns, demand for drinking points rises. Farms should install additional water sources so that lower-ranking animals can also drink without difficulty, Meese said.

Strickhof is also investigating a genetic approach. In 2024, a Holstein calf named Cool Girl was born carrying a natural mutation from a Caribbean cattle breed known as the Slick gene.

Animals with the gene have shorter, smoother coats, more skin folds and larger sweat glands, which may help them regulate their body temperature more effectively.

Meese cautioned that it is too early to assess whether Cool Girl will cope better with heat in Switzerland. The animal is still on a rearing farm, and researchers must determine whether cows with the gene are also suited to colder months. Although countries such as Australia have incorporated the gene into breeding programmes, wider use in Switzerland remains a future prospect.

For now, Meese said, farms in Switzerland can rely on structural measures such as ventilation and cow showers.