The USDA has announced a program to test bulk raw milk for for highly pathogenic avian influenza H5N1.

USDA’s Animal and Plant Health Inspection Service, in partnership with state veterinarians, will begin testing bulk raw milk for highly pathogenic avian influenza H5N1.

USDA believes the testing is necessary to proactively support effective biosecurity measures to contain and eliminate infections in livestock, the agency said in a press release. Since the virus was first detected in dairy cows in Texas in March, there have been 491 cases in 15 states, representing about 2% of licensed dairy herds.

USDA plans to sample milk at the regional level, with additional testing at the farm level if necessary, until herds in an area are determined to be free of the virus. The agency is working with state and private veterinarians on the final details of implementation and will share guidance documents soon.

On board

Government experts have determined an expanded testing program for the H5N1 virus in dairy cattle is necessary, said Jamie Jonker, chief science officer for National Milk Producers Federation.

“Dairy farmers stand ready to assist federal, state and local officials and veterinarians in efforts to better understand and limit the spread of the H5N1 virus in dairy cattle. We await more information from USDA on program implementation,” he said.

California leads

California, the largest milk-producing state, leads the nation for infections. Since its first detection on Aug. 30, the state has had 277 infected herds — 56% of all infected herds in the U.S. and 26% of California’s dairies.

USDA has reported 187 cases in the last 30 days, with 172 of those in California, 13 in Utah and 2 in Idaho.

Testing requirements

In May, USDA implemented a federal order to require the testing of lactating cows before interstate movement, which the agency said has helped to limit H5N1’s spread to new states. USDA has precedent with successful bulk milk testing approaches, including the use of testing to eradicate brucellosis from dairy herds, according to the agency.

In addition, Colorado implemented statewide bulk milk testing after H5N1 was detected in dairy herds in two counties, and the most recent statewide testing has not detected evidence of H5N1 in any herds in the state.

Transmission

USDA continues to emphasize to farmers nationwide that biosecurity is the best weapon against the spread of H5N1, and farms should practice biosecurity even if the virus has not been detected in their state or vicinity.

Data collected over seven months has shown H5N1 can be transmitted on equipment, people or other items that move from farm to farm, including between dairies and poultry facilities.

USDA continues to support the rapid development and timely approval of an H5N1 vaccine for dairy cows, in addition to other species. Two vaccine candidates for use in dairy cows are currently undergoing field trials, according to the agency.

Avian flu infections by state

In addition to California, infections in dairy animals have been detected in:

Colorado: 64

Idaho: 35

Michigan: 29

Texas: 26

Iowa: 13

Utah: 13

New Mexico: 9

Minnesota: 9

South Dakota: 7

Kansas: 4

Oklahoma: 2

Ohio: 1

North Carolina: 1

Wyoming: 1