Dairy herds in Kansas and New Mexico are infected with the H5N1 bird flu virus, raising the U.S. total to 15 herds in six states, said the Agriculture Department on Thursday. Texas has the most infected herds, with seven, followed by Kansas with three and New Mexico with two.
The USDA also reported an outbreak of highly pathogenic avian influenza (HPAI) on an egg farm with 1.9 million hens in Ionia County in central Michigan, midway between Lansing and Grand Rapids. Because flocks are quickly culled to prevent the spread of HPAI, the disease has killed 3.8 million birds in domestic flocks this month.
Authorities say bird flu poses little risk to human health, although it has only recently been found in U.S. cattle. A Texas dairy worker was being treated for mild symptoms of HPAI. The Centers for Disease Control and Prevention says that genetically sequenced samples from infected dairy cows and the farmworker showed they “for the most part lack changes that would make them better adapted to infect mammals.”
On a web page devoted to HPAI in livestock, the USDA said tests had found the virus in a herd in Kansas and one in New Mexico. Its list reflected conditions as of Wednesday at midday. Besides Texas, Kansas, and New Mexico, bird flu has been confirmed in individual herds in Idaho, Michigan, and Ohio.
While HPAI can quickly wipe out a flock, its effect on dairy cattle is far less severe. It reduces appetite and milk output and tends to appear in older animals. Infected cows recover in 10 to 14 days. About 10 percent of cows in a herd contract the disease.
Texas Agriculture Commissioner Sid Miller said in an Agri-Talk interview that he did not expect HPAI to disrupt beef production. Texas is the No. 1 cattle state, with 12 million head, or roughly one of every seven head in the nation.
“The cattle that get it are the older lactating cows, and we don’t have those in the feedlot,” said Miller. “I think we’re OK, but we’re certainly going to research that.”