Technology is in place to improve the quality of milk for cheese production. Kappa-casein is a key protein in the cheese making process because it is the protein which is destabilised by an industrial enzyme known as rennin to make milk coagulate and curdle.
There are three possible gene combinations in a cow for Kappa-casein they are AA, AB and BB. The BB genotype appears to be the most favourable for cheese production. Milk from cows with Kappa-casein genotype BB has been reported to yield 3% to 7% more cheese than milk from cows with AA. We can even go back as far as 1986 to see research reported in the Journal of Dairy Science at that time reflecting an approximate 4% increase in cheese yield from cows with BB than AA.
Gene marking technology can determine which sires and which cows have the BB genotype. Reducing the somatic cell count in the herd will also help to improve cheese yield.
In the US, trends have seen cheese plants paying for milk volume rather than on certain characteristics such as protein and somatic cell count. The cheese plants are in competition with fluid milk processors and see the volume premiums as one way to ensure a steady milk supply.
If plants suddenly decided to change this and offer premiums for cheese yield, producers would be left trying to catch up by revising their breeding programs which can take years to see dividends. Genetic change is a long term process.