As of September 16, the highly pathogenic avian influenza virus H5N1 will be among the “contaminants” sought at slaughterhouses on dairy cow carcasses. This was announced by the United States Department of Agriculture (USDA) on its website on August 13, 2024.
On carcasses at the slaughterhouse
The Food Safety and Inspection Service (FSIS) will conduct the operation, using muscle samples from cull dairy cow carcasses already collected at slaughterhouses under the country’s existing National Residue Program (NRP).
“The sampled carcasses […] are retained by the [abattoirs] pending residue test results, USDA said. This process will not require additional retention time beyond current residue testing protocols.
What will happen to carcasses if H5N1 is detected? USDA “will work with industry to ensure [qu’elles] do not enter the food chain.” Since the first case in March, the United States has recorded 192 cases of H5N1 virus contamination in cattle in 13 states as of July 3, 2024.
Three studies to support this
The initiative builds on three studies conducted by the USDA, the latest of which was conducted in May 2024. The FSIS tested for H5N1 in 109 samples of dairy cow muscle taken at the slaughterhouse.
“No viral particles were detected in 108 of 109 muscle samples,” he explained on May 30. “Viral particles were detected in tissue samples, including diaphragm muscle, from one cow.”
Earlier in May, samples of ground beef were tested from retail stores in states where dairy herds had tested positive for H5N1. No viral particles were found.
U.S. officials also conducted a study on cooking ground beef after inoculating it with “a very high level of virus” to determine whether the cooking temperatures recommended by the FSIS are effective.
“No virus was present in hamburgers cooked to 145 degrees Fahrenheit (63 degrees C) or 160 degrees (71 degrees C, well done), the cooking temperature recommended by the FSIS. Even cooking hamburgers to 120 degrees (49 degrees C) […] has significantly inactivated the virus.”
