By Jamie Martin
A recent Cornell University study revealed how the highly pathogenic avian influenza (HPAI) H5N1 strain is harming the U.S. dairy industry.
The virus causes severe mastitis in cows, reducing milk production and leading to significant economic losses for farmers.
The study, published in Nature Communications, highlighted the impact of HPAI on a herd of 3,876 cows in Ohio. The affected cows faced higher risks of death and early removal from the herd.
Researchers estimated a loss of $950 per infected cow, totaling around $737,500 for the single herd studied.
“The farm did its best to isolate the affected animals,” said researcher Felipe Peña Mosca. However, despite efforts, the virus spread rapidly within 23 days, impacting 20% of the herd. Of the 777 cows affected, nearly 40% left the herd within two months due to death or decreased productivity.
Virology expert Diego Diel explained that although pasteurization makes the milk safe, the production losses hurt farmers financially. Diel stated, “This represents a shock to production costs if you are affected by an outbreak.”
Research shows that regular mastitis treatments, designed for bacterial infections, may not prevent the viral spread during milking. In fact, the cleaning process could risk further transmission.
Laboratory tests confirmed that the virus spilled over from wild birds in early 2024. Since then, scientists have been studying its effects on food safety and animal susceptibility. The HPAI outbreak, already costing the poultry industry $1.4 billion, now threatens the 9.3 million-cow U.S. dairy sector.
The researchers stress the need for stronger biosecurity measures and the development of vaccines. Unlike poultry farms, open dairy barns make controlling exposure to wild birds more challenging.
The team believes continued research is vital to reduce the long-term risks of this evolving virus on dairy farms nationwide.
Photo Credit: cornell-university
Categories: National