Aarhus University Seal / Aarhus Universitets segl

Coding for curdling: genetics and the good cheese

Not all cows are equal when it comes to producing milk that is suited for cheese-making. Scientists are close on the trail of the specific genes that code for milk with good curdling ability.

2012.12.17 | Janne Hansen

Christian Bendixen

Production of cheese, yogurt and other dairy products is dependent on the ability of milk to coagulate. When milk coagulates, it is transformed from being liquid to becoming a solid and cohesive mass.

Not all cows are equally good ”cheese cows” because their milk has a poor or no ability to coagulate. Scientists from Aarhus University have found that the ability of milk to coagulate is a heritable trait in cows, and the researchers have identified the gene responsible for almost half of the variation in the milk’s coagulation ability. Now the Danish National Advanced Technology Foundation has given a grant of five million kroner to a project in which the scientists can delve deeper into the genetic conditions and develop a practical gene test for coagulation ability.

- We have identified one of the genes affecting coagulation and would now like to find and describe the particular mutation that destroys the milk’s ability to coagulate. With this knowledge we can develop a gene test that relatively quickly can identify the cows and bulls that are carriers of the defect gene, says research professor and leader of the new project Christian Bendixen from Aarhus University.

Competitive edge

Poor milk coagulation is a very timely problem because an increasing number of cows  produce milk with a poor or no ability to coagulate. Swedish studies show that 17 per cent of Swedish cows produce non-coagulating milk.

At the dairy the poorly-coagulating milk is automatically blended with the good ”cheese milk”, thereby reducing the milk’s average coagulation ability. Genetic variation leads to large fluctuations in milk quality with respect  to cheese-making, reduces cheese yields, and makes it necessary to add calcium chloride to the milk in order to improve coagulation.

Danish researchers have found that even though only a small portion of Danish cows produce milk with no ability to coagulate, up to 20 per cent of the cows produce milk with a poor ability to coagulate. There is thus a lot of room for improvement.

- We have an excellent opportunity to gain a competitive edge by acting quickly and developing a gene test and implementing it in the national breeding programmes. The goal is to eliminate the gene for lack of coagulation ability and increase the number of cows having a good coagulation ability, says Christian Bendixen.

The three-year project, which has a total budget of 11 million kroner, will be carried out in collaboration with Arla Foods and Viking Genetics. 

For more information please contact

Research professor Christian Bendixen
Department of Molecular Biology and Genetics, Aarhus University, Denmark
e-mail: christian.bendixen@agrsci.dk, telephone: +45 2476 5330, mobile: +45 2476 5330

Public / media, Department of Molecular Biology and Genetics, Knowledge exchange