The ground-breaking research is being conducted by Agriculture Victoria with researchers studying heat tolerance in dairy cows.
Researchers now believe they are one step closer to unlocking the genetic code to breeding more heat-resistant cows.
Agriculture Victoria research director Ben Cocks said researchers have identified five new genes strongly associated with heat tolerance in dairy cows.
He said the findings came after studying almost 500,000 milk records from approximately 30,000 Holstein cows – a six-fold increase in sample size from prior comparable studies.
“This large increase in sample size has helped the team pinpoint the specific regions in the cow’s DNA that controls heat regulation, helping us better identify which cows are more heat tolerant than others,” Dr Cocks said.
Dairy cows reduce their feed intake when temperatures and humidity rise, resulting in a decrease in milk production.
In areas such as Northern Victoria, it means more than 100 days each year are considered too hot for dairy cows to produce optimal amounts of milk.
Dr Cocks said by breeding cattle that can adapt to rising temperatures, it could create a more resilient dairy industry in a changing climate.
“This gives farmers the support they need to minimise the impact of heat on their herds and maintain milk production,” he said.
The research team at Agriculture Victoria are using the results from this study to begin a five-year research project that will test and compare the newly found heat-tolerant genes with DNA from dairy cows across Australia to find new ways to identify the most heat-tolerant cows for farmers to breed.
The study is part of the DairyBio program – a $55 million research partnership between Agriculture Victoria, Dairy Australia and the Gardiner Foundation.
