Dairy NZ chief scientist Dr Eric Hillerton says latest research into the dairy industry's biggest health concern, mastitis, is focusing on why some cows never get the udder infection.
Dr Hillerton, who has recently been appointed the president of the international organisation, the National Mastitis Council, says research shows that about 40% - 50% of cows never get mastitis.
He says it's a significant number and they're now trying to work out why these animals don't contract the infection.
Dr Hillerton says about 10% - 15% of cows get mastitis each year.
He says the focus has moved to those cows which never get mastitis to understand why that is, what controls it, whether it's the immune system or the teat, and to get more of these animals into the herd.
Dr Hillerton says research is also still ongoing into creating a vaccine to protect cows from mastitis infections.