The agency says the animal was "never presented for slaughter for human consumption, so at no time presented a risk to the food supply or human health. Additionally, milk does not transmit BSE."
AP is reporting that "Baker Commodities says cow tested positive for mad cow disease at its Hanford, Calif., plant."
Cattle futures tumbled on news of the discovery, according to Dow Jones.
Update 1:55 p.m. From the California Dept of Public Health:
There is no public health threat due to the discovery of BSE in a dairy cow. The food supply in California has not been affected by this discovery, and residents do not need to take any specific precautions. The California Department of Food and Agriculture has many procedures in place to keep this disease from entering the food chain, and the detection found is evidence that the system of safeguards is working. The cow in question was not slaughtered for food and BSE is not transmitted in milk.
CDPH will continue to monitor the situation and will advise Californians of any new information.
Center for Science in the Public Interest, a food nutrition and safety advocacy organization, concurs...with reservations...
WASHINGTON--A case of a single cow with Bovine Spongiform Encephalopathy is not a reason for significant concern on the part of consumers, and there is no reason to believe the beef or milk supply is unsafe.
If the cow were exposed to the typical strain of BSE via animal feed—and the government says that’s not the case here—that would have represented a significant failure. The government’s ability to track down other cattle that may have been exposed via feed would have been hampered without an effective animal I.D. program.
The United States has first-world resources and technology but a third-world animal identification system. In fact, some third-world countries do a better job of tracking livestock than America does. Botswana, for one, uses RFID microchips to track its animals up and down the supply chain. If American cattlemen suffer economic losses at the news of this discovery of BSE, they should blame only themselves and other opponents of a mandatory animal identification system.
Here's a video press release of USDA Chief Veterinary Officer John Clifford discussing the outbreak...
Statement from USDA:
WASHINGTON, April 24, 2012 – USDA Chief Veterinary Officer John Clifford today released the following statement on the detection of BSE in the United States:
"As part of our targeted surveillance system, the U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed the nation's fourth case of bovine spongiform encephalopathy (BSE) in a dairy cow from central California. The carcass of the animal is being held under State authority at a rendering facility in California and will be destroyed. It was never presented for slaughter for human consumption, so at no time presented a risk to the food supply or human health. Additionally, milk does not transmit BSE.
"The United States has had longstanding interlocking safeguards to protect human and animal health against BSE. For public health, these measures include the USDA ban on specified risk materials, or SRMs, from the food supply. SRMs are parts of the animal that are most likely to contain the BSE agent if it is present in an animal. USDA also bans all nonambulatory (sometimes called "downer") cattle from entering the human food chain. For animal health, the Food and Drug Administration (FDA) ban on ruminant material in cattle feed prevents the spread of the disease in the cattle herd.
"Evidence shows that our systems and safeguards to prevent BSE are working, as are similar actions taken by countries around the world. In 2011, there were only 29 worldwide cases of BSE, a dramatic decline and 99% reduction since the peak in 1992 of 37,311 cases. This is directly attributable to the impact and effectiveness of feed bans as a primary control measure for the disease.
"Samples from the animal in question were tested at USDA's National Veterinary Services Laboratories in Ames, Iowa. Confirmatory results using immunohistochemistry and western blot tests confirmed the animal was positive for atypical BSE, a very rare form of the disease not generally associated with an animal consuming infected feed.
"We are sharing our laboratory results with international animal health reference laboratories in Canada and England, which have official World Animal Health (OIE) reference labs. These labs have extensive experience diagnosing atypical BSE and will review our confirmation of this form of the disease. In addition, we will be conducting a comprehensive epidemiological investigation in conjunction with California animal and public health officials and the FDA.
"BSE is a progressive neurological disease among cattle that is always fatal. It belongs to a family of diseases known as transmissible spongiform encephalopathies. Affected animals may display nervousness or aggression, abnormal posture, difficulty in coordination and rising, decreased milk production, or loss of body weight despite continued appetite.
"This detection in no way affects the United States' BSE status as determined by the OIE. The United States has in place all of the elements of a system that OIE has determined ensures that beef and beef products are safe for human consumption: a mammalian feed ban, removal of specified risk materials, and vigorous surveillance. Consequently, this detection should not affect U.S. trade.
"USDA remains confident in the health of the national herd and the safety of beef and dairy products. As the epidemiological investigation progresses, USDA will continue to communicate findings in a timely and transparent manner."
From the California Dept of Agriculture: BSE in the United States...
On March 13, 2006, BSE was confirmed in a non–ambulatory, approximately 10–year old crossbred beef cow sampled on a farm in Alabama by a private veterinarian. No part of the animal entered the human or animal food chain. The cow had resided on the farm for less than a year. The investigation has been completed.
On June 24, 2005, BSE was confirmed in a cow slaughtered in November 2004. The cow was sampled for BSE at a pet food facility in Texas. DNA tests confirmed that the approximately 12–year old Brahma–cross cow was born and raised in Texas. The herd was quarantined and cattle that were in a similar birth group and/or ate the same feed as the infected cow were traced and removed.
The first case detected in the U.S. was confirmed on December 25, 2003, by The Veterinary Laboratories Agency in Weybridge, England. This case was in an adult Holstein cow slaughtered in the State of Washington. The epidemiological investigation and DNA test results confirmed the infected cow was not indigenous to the U.S., but was born and became infected in Alberta, Canada. Animals with known or potential risk for having been infected with the BSE agent and all progeny from the index cow in the U.S. were depopulated. All carcasses were properly disposed of in accordance with Federal, State, and local regulations.
- About BSE (CDC)