Heat-stressed dairy cows – A One Health challenge in a changing climate
Lactating dairy cows are sensitive to heat. When temperatures rise, keeping cool becomes difficult, leading to heat stress that harms animal health, welfare, and milk production. Lena-Mari Tamminen's research group tackles heat stress in dairy cows from two angles - management and breeding.
"Lactating dairy cows are sensitive to heat. When temperatures rise, keeping cool becomes difficult, leading to heat stress that harms animal health, welfare, and milk production. Even temperatures above 20 °C, typical of Swedish summers, can cause stress if no cooling measures are used. As the climate warms, average temperatures and the frequency of heatwaves are expected to rise, making this an increasingly urgent challenge for dairy farmers", says Lena-Mari Tamminen.
Could you provide a brief overview of your projects?
"Our research tackles heat stress from two angles: management and breeding. While cooling technologies for dairy cattle have been studied worldwide, most research comes from hot regions where barns and management systems differ from those in temperate climates. In Sweden, insulated barns designed for cold winters may trap heat during summer and water-based cooling can increase humidity, worsening heat stress and affecting pathogens in the barn environment. Thus, there is a need to evaluate the effect of different cooling methods in a Swedish context."
"A complementary strategy is to strengthen cows’ natural heat resilience through breeding. In our project we explore variation in heat tolerance among cows to understand what defines heat resilience and explore if these traits are feasible to include in a breeding program and which potential trade-offs required."
"In these two projects we combine intervention studies, large scale observational studies with farmer interviews and stakeholder workshops to identify the most viable path forward. This interdisciplinary approach helps evaluate both practical feasibility and broader societal implications of different strategies."
How does the research relate to the One Health concept?
"By linking climate adaptation, animal health, and sustainable food production our work directly contributes to the One Health concept, recognizing that healthy animals, people, and environments are interconnected. Tackling heat stress in dairy cows is not only about keeping animals cool, but about protecting food security and building resilience in the transition towards a more sustainable dairy production in a warming world."
Management-based cooling is explored in the project Are Swedish cows cool enough? (funded by Seydlitz MP Bolagen), while genetic solutions are examined in the project “From Sensitive to Robust Athlete – Exploring the Potential of Genomic Selection to Help Dairy Cows Cope with Increasing Temperatures” (funded by Formas)."