Science - April 15, 2004

Genomics research will help create cheese cows, milk cows and health cows

Cows today still just produce ordinary milk, but ten years on things may well have changed. That’s when a recently initiated project will be coming to an end, by which time we may be able to distinguish between cows that make milk for the cheese industry, cows that produce milk for milk and yoghurt, and cows that produce raw materials for expensive health products.

Last Tuesday morning President of the Executive Board of Wageningen UR, Professor Aalt Dijkhuizen, signed an agreement with Tiny Sanders of the Dutch Dairy Organisation and Dr Jan Jansen of the cattle breeding cooperative Delta to mark the official start of a project worth 1.7 million euros. The researchers will examine the genes in cows that determine the type and quantity of proteins and fat in the milk they produce. They hope to find variants that are responsible for cows producing less saturated fats and more unsaturated fats in the milk for example.

It is also possible that they will find genes that are responsible for the production of the proteins that go into cheese making. Armed with this knowledge, breeders will be able to produce cows with fewer whey proteins in their milk and more cheese proteins. But the opposite, a cow that produces more whey proteins, may also be attractive as some whey proteins have interesting medicinal properties, such as the ability to lower blood pressure or stimulate the immune system. Cow milk proteins at present consist of seventy percent cheese proteins, and the rest is whey protein. Whey proteins used to disappear into animal feed, but manufacturers of supplements and food ingredients are becoming increasingly interested in these.

Tiny Sanders, who is responsible for the Wageningen research department at Campina milk company, describes the international research arena. “There are already big genomics projects running in Australia and the US. Eighty scientists are working full time on the cow genome. There is no point trying to compete directly with this work, but our project has found an interesting niche.”

The research alliance will make use of the data that comes out of the big genomics programme, which is due to publish the entire cow genome in 2005. “We are going to concentrate on the genes that are relevant to milk,” continues Sanders. “The international researchers are mapping the genes, but the Dutch plan to focus on variation within genes.”

Wageningen chair of Animal Breeding and Genetics, Professor Johan van Arendonk, explains further: “We plan to confine ourselves to Holstein cows. First we will examine the genes of twenty breeding bulls and the performance of their descendants, then we will look at the DNA and the milk of another two thousand dairy cattle.”

The project is financed by EU subsidies and the province of Gelderland, and the organisers are also hoping for support from the Dutch government. The aim is to produce knowledge which will enable Dutch breeders and dairy companies to improve their market competitiveness. “This is the only way to prevent the Netherlands slipping behind on the international market,” says Sanders.

Willem Koert

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