Farms.com Home   News

U.S. Department of Agriculture detects second bird flu strain in dairy cattle

U.S. dairy cattle tested positive for a strain of bird flu that previously had not been seen in cows, the U.S. Department of Agriculture said on Wednesday, ramping up concerns about the persistent spread of the virus.

The H5N1 virus has reduced milk output in cattle, pushed up egg prices by wiping out millions of hens, and infected nearly 70 people since April as it has spread across the country.

Genome sequencing of milk from Nevada identified the different strain, known as the D1.1 genotype, in dairy cows for the first time, the USDA said. Previously, all 957 bird flu infections among dairy herds reported since last March had been caused by another strain, the B3.13 genotype, according to the agency.

Reuters reported news of the detection of the second strain on Wednesday ahead of USDA’s announcement.

The second strain was the predominant genotype among wild birds this past fall and winter and has also been found in poultry, the USDA said. It was identified in dairy cattle through an agency program that began testing milk for bird flu in December.

“We’re seeing the H5N1 virus itself be smarter than all of us,” said Beth Thompson, South Dakota’s state veterinarian.

“It’s modifying itself so it’s not just staying in the poultry and the wild waterfowl. It’s picking up a home in the mammals.”

Click here to see more...

Trending Video

Advancing Swine Disease Traceability: USDA's No-Cost RFID Tag Program for Market Channels

Video: Advancing Swine Disease Traceability: USDA's No-Cost RFID Tag Program for Market Channels

On-demand webinar, hosted by the Meat Institute, experts from the USDA, National Pork Board (NPB) and Merck Animal Health introduced the no-cost 840 RFID tag program—a five-year initiative supported through African swine fever (ASF) preparedness efforts. Beginning in Fall 2025, eligible sow producers, exhibition swine owners and State Animal Health Officials can order USDA-funded RFID tags through Merck A2025-10_nimal Health.

NPB staff also highlighted an additional initiative, funded by USDA Animal and Plant Health Inspection Service (APHIS) Veterinary Services through NPB, that helps reduce the cost of transitioning to RFID tags across the swine industry and strengthens national traceability efforts.

Topics Covered:

•USDA’s RFID tag initiative background and current traceability practices

•How to access and order no-cost 840 RFID tags

•Equipment support for tag readers and panels

•Implementation timelines for market and cull sow channels How RFID improves ASF preparedness an