A2 milk is gaining attention in the dairy sector, but what does it mean for your herd and bottom line?
What Is A2 Milk?
Milk contains beta-casein, a protein with two genetic forms: A1 and A2. Cows with the A2A2 gene produce milk with only the A2 protein. Breeds like Jersey, Guernsey, Normande, and Brown Swiss are more likely to carry the A2 gene than Holsteins.
Testing and Breeding
Genomic testing can identify the A1/A2 status of cows and heifers, helping guide breeding and culling decisions. A2A2 animals bred together will always produce A2A2 offspring, allowing a gradual shift toward A2 milk production.
Research Insights
The University of Minnesota tested its herd and found over 50% of Holsteins were A2A2, despite no active selection for the trait. Their crossbred herds also showed a mix of A2 status across breeds, with Normande- and Jersey-sired crosses showing higher A2A2 percentages.
| Breed | % A2A2 |
|---|---|
| Holstein | 56% |
| 1964 Holstein | 26% |
| Holstein-sired crossbred | 49% |
| Jersey-sired crossbred | 47% |
| Montbéliarde-sired crossbred | 36% |
| Normande-sired crossbred | 50% |
| Viking Red-sired crossbred | 45% |
Potential Benefits
While A2 milk is marketed as easier to digest, scientific evidence remains limited. A joint study by UMN and Penn State found differences in performance between A2A2 and A1A1 cows, but not between A2A2 and A1A2. Results may have been influenced by farm-level decisions.
Bottom Line
If market demand or premiums for A2 milk emerge, selecting for A2A2 genetics may be worthwhile. However, it’s important to prioritize overall genetic merit to maintain herd performance and profitability. More research is needed to confirm the broader benefits of A2 genetics.
