Rio Mais Leite Project Launches A2A2 Genotyping in Assisted Dairy Herds

On-farm tests conducted during animal health management visits identify cows with potential for A2 milk production

A2 milk has gained prominence as a market trend associated with the growing demand for differentiated products aimed at specific consumer groups. Produced by cows that carry exclusively the A2 beta-casein protein, this milk is considered easier to digest for some individuals, increasing interest across the dairy sector in tools capable of identifying this genetic trait in dairy herds.

Within this context, the Instituto BioSistêmico has initiated A2A2 genotypic screening as part of the Rio Mais Leite Project. The action was carried out during animal health management visits in November to participating farms and marked the first round of rapid on-farm testing to identify A2A2 animals within the herds.

A2A2 genotyping makes it possible to map cows with the potential to produce exclusively A2 milk and can be performed through laboratory-based DNA tests or rapid tests applied directly on the farm. This approach allows producers to access strategic genetic information in a practical and accessible manner.

The visits were conducted by William Eduardo da Silva, veterinarian and IBS consultant, who explains that producers were instructed to previously collect milk samples and store them properly so that testing could be performed during the technical visit. In addition to genotyping, the visits also reinforced good animal health management practices, including a review of the technical recommendations addressed throughout the year.

“We reviewed everything that had already been worked on with the producers, adjusting certain points and reinforcing improvements that have brought results to the farms. It is a moment to consolidate the work that has been done,” the consultant explains.

Producer Acceptance and New Perspectives for the Herd

According to William, producer acceptance of the technology was very positive, particularly because it dispelled the idea that A2A2 genetics are restricted to highly specialized herds. “Even working with crossbred animals, all the producers assisted had at least one A2A2 animal in the herd, which surprised and motivated many of them,” he reports.

Identifying these animals opens up new opportunities, especially for producers who manufacture artisanal cheeses, sell milk directly to consumers, or allocate part of their production for household consumption. “For many, it was important to realize that this genetic trait is already present in their herds and that it may represent a future opportunity for product differentiation,” he adds.

According to Matheus Henrique Magalhães, Technical Coordinator for Livestock Projects at IBS, all bulls used in the Fixed-Time Artificial Insemination (FTAI) protocols of the Rio Mais Leite Project are A2A2 bulls, selected in partnership with artificial insemination centers.

“This choice ensures that the project’s genetic improvement strategy is aligned with A2 milk production, while testing in cows aims to identify the presence of this genetic trait in the assisted herds,” Magalhães explains.

Next Steps to Strengthen A2A2 Genetics

Currently, none of the assisted producers have fully A2A2 milk production systems or perform milk segregation based on this genetic profile. However, all producers now have identified A2A2 animals within their herds and received guidance on the importance of, in the future, separating this milk for personal consumption, direct sales, or potential bonus programs offered by dairy processors.

Next steps include expanding the number of tested animals and strengthening genetic improvement strategies on the farms, with technical recommendations to mate A2A2 cows with A2A2 bulls, ensuring the permanence of this trait in the herd over time.

This initiative reinforces IBS’s commitment to delivering innovation, technical knowledge, and practical technologies aligned with the realities of dairy producers, contributing to milk valorization and the strengthening of regional dairy farming.

About the Rio Mais Leite Project

Designed and implemented by the Instituto BioSistêmico, the Rio Mais Leite Project is funded by the Zoetis Foundation and focuses on the development of dairy farming in 100 family-based dairy farms located in the southern region of the state of Rio de Janeiro.

The initiative includes technological assistance actions organized into four main areas: good practices, reproductive management, nutritional management, sanitary management, and good practices in artisanal cheese processing.

The project uses the CheckMilk methodology, which includes a digital platform with a management system and a mobile application to support the work of technical teams and producers, providing continuous support for farm routines.