Consumption of A2 milk from indigenous breeds is becoming a preference among consumers for the benefits they are increasingly experiencing. Various studies have been done and many more are in progress to scientifically validate on the selective consumption of A1 versus A2 milk.
Cow milk is about 87 percent water and 13 percent solids; a combination of fat, carbohydrates in the form of lactose, minerals, and protein. The 30 to 35 percent of protein in milk, equivalent of two teaspoons per liter, is the beta-casein; of which there are several varieties, determined by the genes of the cow. The most common of these variants are A1 and A2 proteins. The two proteins are almost identical — they each contain 209 amino acids, the building blocks of any protein. The only difference between A1 and A2 is a difference in the 67th amino acid in the chain. At this position, A1 has a histidine amino acid, while A2 has a proline amino acid.
The problem with A1 milk is this very pesky histidine amino acid at position 67. That one amino acid change means when the A1 protein is broken down in your gut, it can create the peptide BCM-7. It is known that peptides can have all kinds of effects on the human body because of BCM-7. They can affect the blood pressure, your immune system, and how your blood clots. However, the A2 protein breakdown in the gut does not create BCM-7 and research and individuals' experience proves that people who are lactose intolerant can consume raw A2 milk without any discomfort.
Genetics of A1-A2 inheritance
Animals contains 2 different doses of Beta Casein gene responsible and based on the number of copies, the animal can be pure homozygous A2 (notated as A2A2); pure homozygous A1 (notated as A1A1); or heterozygous notated as A1A2, wherein one copy of A1 and one copy of A2 gene are present in the animal. One can estimate the probability of A1, A2, mixed animal ratios for the subsequent generation depending on the available animal pool with them. Typically, A2A2 parents always produce 100% homozygous A2 calves.
One cannot morphologically identify which protein a cow or bull can produce, it can be determined only through the genetic test. So it is imperative that all native breeds are not necessarily pure A2, because of the rampant cross-breeding with A1 cows. Hence new technologies and laboratory tests to identify milk protein produced by cows is posing a great advantage for the benefit of consumers and farmers alike to determine the purity of A2 milk.
A1A2 lab testing is performed using 2ml of blood sample in EDTA tube or hair roots (20-40 freshly plucked) from the cattle. The sample is used to extract DNA and then selectively amplifying the DNA region responsible for A1, A2 genotype several folds and visualizing the same on a gel. The test uses PCR (Polymerase Chain Reaction) technology which is the gold standard for genotyping studies. It is highly economical and reliable to test the animal sample rather than milk directly.
Pic: A PCR Test Validation of A1A2 genotype
The percentage of the A1 and A2 beta-casein protein varies between herds of cattle, and also between countries and provinces. While native breed African and Asian cattle historically produce only A2 beta-casein, the A1 version of the protein is common among cattle in the western world. Indian Desi breeds today however many not be pure A2 until tested.
A dairy farm that produces pure A2 milk must test every cow genetically for A1-A2, especially using the blood or hair sample. While the tests are also being done on milk samples its accuracy cannot be same as DNA derived PCR test.
These new ( or rather going back to the old ways of dairy farming) methods and dynamics are helping the progressive dairy farmers to take decisions in regard to the cow breed purchase, production management and also their in-house breeding program management. Small and medium dairy farmers are fighting against all odds to balance costs and revenue on per liter of milk, turning their farms into native breed farms, creating an alternate direct market of farm-to-home model, turning themselves into entrepreneurs.
However, establishing a new or switching to a pure A2 milk dairy farm is not an easy task in an industrialized market driven economy. It takes lot of support from the consumers, those who value quality over price. In he last few years the pandemic have shaken up the consumer behavior to at least start taking food and health seriously. We have started realizing that cost and quality are inversely proportional, and in any economy consumer demand drives production methods and product choices, and in the case of milk the switch to native breed cow milk has begun.
Look around your town, visit a farm, build a relationship with the farm to get natural farm-to-home produce; this goes a long way in your and families' health.
Know the source of your food.
Moolrasa a2 milk is supple, odourless and sweet; it’s the way milk’s meant to be.
Over the past four years, moolrasa has been delivering natural, raw A2 protein milk (desi cow milk) directly to our communities in Hyderabad. Call us today to know more: +91 9100515253.
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