The genetics behind cheese

Does Swiss cheese come from Swiss cows? How about blue cheese? Professor of animal science at McGill University's Macdonald campus KF Ng-Kwai-Hang has the answer to these questions. He has spent the last 25 years studying the genetics of cows and how this affects quality and types of cheese. Basically, cheddar cheese can be made from all milk, but the taste and quality will be different from breed to breed and also within a breed.

Ng has identified the role of specific milk protein genes that affect cheese yield, composition and quality. He and has research team have found that small changes or mutations in the DNA of certain genes lead to changes in the protein, which results in dramatic changes in the cheese. Their findings show that a mutation in the particular protein, the kappa-casein, is associated with a higher yield of cheese and one which is better quality.

According to Ng, in addition to the two genetic variants for kaapa casein mentioned above, there are about 50 known milk protein gene variants and they have diverse effects on dairy product production. These findings have generated a great interest in the dairy industry. Attempts are under way in some countries to breed for specific genetic variants.