Beta-casein typically compromises about 30% of total protein in cows’ milk. Owing to genetic variation it may be present in milk as one of many variants in modern cattle; with A1, A2, A3, B, C and I the most prevalent variants in Western dairy herds.
Beta-casein variants differ from one another by virtue of amino acid sequence, this has an impact on the structure that the protein adopts and subsequently the way it is digested. One amino acid difference at position 67 of the protein allows the preferential production of a protein fragment termed BCM-7 from the A1 and related variants, but not A2 nor variants that share a common structure at this part of the protein. On this basis beta-casein can be generally divided into either A1-type or A2-type.
The A1-type of beta-casein has been linked to intolerance type responses and its exclusion from milk may allow people who have previously limited dairy intake to benefit from the nutritional goodness it offers.
Further information relating to research on beta-casein variants and bioactive fragments generated from their digestion can be found at www.betacasein.net. CRV can test your current herd for A2 status via our Nasal Swab Test, DNA Parentage testing or Herd Testing.
If you only require the A2 Beta Casein status of a group of animals, not the full DNA Profile and Parentage, the Nasal Swab test may suit you. Simply order the number of tests you require with your CRV Field Consultant, take the swabs as below, and we will email you the results within 5 days of the lab receiving the samples.
The test analyses the DNA taken from the nasal swab sample for Beta Casein type (A1 or A2 type), and is carried out by Analytica Laboratories Ltd.
The nasal swab sampling method is recommended for testing youngstock or small groups of mature animals, due to ease and safety.
We also offer a Milk Test for A2 Beta Casein status, should you require results for a large group of milking animals.
You will receive a report of the results via email, 5 days from the time the lab received the samples. CRV myHERD clients will have the results for each animal uploaded to myHERD.
Results are only for Beta Casein A2 status, this is not a full DNA test.
CRV has the ability to analyse Herd Test milk samples for beta-casein types. This can be bulk milk, or per animal.
This will result in a cow being classified into one of three categories;
1. A2/A2: This phenotype will result in only A2 type beta-casein in the milk.
2. A1/A2: This phenotype will result in an equal amount of A1 and A2 type beta-casein in the milk.
3. A1/A1: This will result in an onlyA1 type beta-casein in the milk.
myDNA confirms your herd’s parentage* and A2 status of your animals.