Avian Influenza: The Beef Meat Sector Is Not (Yet) Affected

Since 2024, avian influenza has no longer been limited to birds. In the United States, the highly pathogenic H5N1 virus underwent cross-species transmission by infecting dairy cows, causing a sharp drop in milk production and a lasting disruption to health surveillance. This situation has led several countries to reassess their vulnerabilities. In Australia, an official report examined a feared scenario: the potential impact of the influenza virus on beef cattle operations. While the risk was deemed negligible, uncertainties remain.  

An American exception, not a universal model

The U.S. episode marked a turning point. For the first time, an avian influenza virus—clade 2.3.4.4b—circulated sustainably among dairy cows, with transmission occurring between animals. This situation remains, at this stage, unique. Outside the United States, targeted surveillance programs conducted in Canada, the United Kingdom, and Germany have detected no bovine infections, despite intense circulation of the virus among wild birds. The Australian report emphasizes that beef cattle have a very different profile from that of dairy cows. In fact, the virus replicates primarily in the mammary gland, where it is shed in extremely high concentrations in raw milk. However, adult beef cattle are almost never exposed to milk from other animals.  

Low Risk of Introduction, Highly Unlikely Spread

According to the analysis, transmission of the virus from birds to beef cattle remains possible but rare. Data collected over several decades show that such cross-species transmissions occur only sporadically. Even assuming the virus is present in birds in Australia, the probability of beef cattle becoming infected is considered low, and the likelihood of spread between herds is deemed negligible. Unlike dairy cows, beef cattle do not share milking systems or equipment contaminated with milk, which have been identified as the primary vectors of transmission in the United States. The respiratory and digestive routes, which have been tested experimentally, do not appear to facilitate effective transmission between animals.  

Limited Health and Economic Consequences

In the event of infection, the expected consequences in beef cattle would be minor. Experimental studies indicate mild and transient clinical signs in non-lactating animals. The mortality rate observed on U.S. dairy farms remains moderate, and no lasting effects on the growth or reproduction of beef cattle have been demonstrated at this stage. Economically, the impact on meat production is expected to be minor compared to what is observed in the dairy sector, with limited direct losses. However, the report emphasizes a significant point: the commercial and regulatory repercussions. Export restrictions or stricter control measures could weigh on an industry that is heavily oriented toward international markets.  

A Low but Evolving Risk

The authors remain cautious, however, due to one key factor: the evolution of the virus. Clade 2.3.4.4b has demonstrated an unusual ability to infect a wide range of mammals. Each new host represents an opportunity for adaptation. If the virus were to find an effective transmission route independent of milk, the public health situation could change. That is why the report recommends strengthening biosecurity, preventing any contact between cattle and wild birds, and developing response strategies tailored to non-avian species now.