The beta-casein protein produced by dairy cows in their milk is controlled by a single gene. As it is a genetic trait, the type of beta-casein that cows produce will not change during their life, and farmers can also use selective breeding to influence the genetics in calves that they breed in their herds.
Analytica’s testing helps dairy herd owners to produce milk that meets a particular beta-casein specification by confirming the genetic makeup of individual animals, as well as monitoring the A1 type beta-casein being produced in the bulk milk of a herd or group of animals. Please note that this testing is only designed for use in bovine (cattle) animals – not with other milking species like goats or sheep.
Individual animal testing
Every animal has 2 copies of the beta-casein gene. If both copies are A1, then the animal has an A1/A1 genotype and will only produce A1 type beta-casein in its milk. If both copies are A2, then the animal has an A2/A2 genotype and will only produce A2 type beta-casein in its milk. Animals with one copy of each gene have an A1/A2 genotype, and produce 50% of each of A1-type and A2-type beta casein.
- Analytica’s DNA testing service can be used with any animal to confirm its genetic makeup – female or male, young or old. Analytica recommends its use in males or young (non-milking) animals, and can work with a range of sample types to carry out a DNA test.
- For milking cows, testing the protein in a milk samples collected from each individual animal is the best option (cost, speed, and accuracy) for confirming the beta-casein type of milking cows. Farmers can send individual samples direct to Analytica, or arrange with their herd testing provider to send sub-samples of milk collected at a herd test to Analytica.
Bulk milk monitoring
A sample of the bulk milk being produced by a herd or group of animals can be tested to identify how much A1 type beta-casein is in there. The test reports the percentage of the beta-casein in a sample that is A1-type with a reporting limit of 1%, and can be compared with any specification or requirement that the herd owner may wish to work to.
Sending and preserving samples
Liquid milk samples can be sent to Analytica from around NZ using normal courier systems. They can also be sent from other countries by following our instructions about how to send samples from overseas.
If shipping samples in NZ, its best if they are frozen prior to shipping, and that an insulated shipping container with frozen cooler pads is used to keep samples chilled for as long as possible during transit. Bronopol preservative can be used to give further protection. If shipping from overseas, please contact us to learn about a simple preservation technique that we have confirmed can be used to protect liquid milk samples during a longer shipping period.