Bovine Spongiform Encephalopathy (BSE) Confirmed in Washington State

Obviously the big news during the holidays has been the discovery and confirmation of Bovine Spongiform Encephalopathy (BSE), also known as “mad cow disease,” in a cull Holstein cow that was slaughtered on December 9, 2003 in Washington state. Test results from a laboratory in Ames, Iowa and later (12-24-03) in England confirmed that the cow was infected with BSE.

The remaining cattle on the farm from which the cull cow came has been quarantined and the decision has not yet been made regarding the disposal of the entire herd. As you know, the USDA has conducted a surveillance program for BSE since 1990 and this procedure located this animal. This case was discovered at a federally inspected slaughter plant where animals are inspected prior to slaughter. The central nervous system tissue from the animal, which scientists recognize as the infective material, did not go into the food chain. We know you are getting phone calls on the subject and hope that this material will aid you in responding to questions.

What is Bovine Spongiform Encephalopathy (BSE)?
Bovine Spongiform Encephalopathy (BSE), also know as “mad cow disease,” is a chronic degenerative disease that affects the central nervous system of cattle. Since 1986, when the disease was first diagnosed in Great Britain, there have been more than 180,000 cases world wide. Countries in which BSE has been diagnosed include: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Israel, Italy, Japan, Luxemburg, Liechtenstein, the Netherlands, Northern Ireland, Poland, Portugal, Slovakia, Slovenia, Spain and Switzerland. However, more than 95 percent of all the BSE cases that have occurred in the United Kingdom.

How is BSE transmitted?
The only way that BSE spreads is through the consumption of feed contaminated with ruminant nervous system residue. Cattle that consumed contaminated feed may develop BSE 4 to 8 years later. The U.S. Food and Drug Administration (FDA) instituted a ban of the feeding of feed that
contained ruminantly-derived meat and bone meal in 1997. This ruling, and the testing of suspect animals served as “fire walls” that contributed to the prevention of BSE in the U.S. cattle population.

What are the symptoms of BSE in cattle?
Cattle with BSE display gradual changes in behavior with include: 1. Changes in temperament such as nervousness or aggression. 2. Abnormal posture. 3. Coordination problems. 4. Difficulty in rising or walking. 5. Decreased milk production. 6. Severe muscle twitching. 7. Loss of body weight despite presence of a normal feed consumption. Following the onset of the signs, the animal’s condition deteriorates rapidly until it dies, usually within 6 months. The disease is fatal and there is no known cure.

Can BSE be transmitted by contact with other animals?
There is no evidence that BSE can be spread by contact between animals or from cattle to other species. There is more evidence which suggests that maternal transmission may occur at an extremely low level. British research shows that there is approximately a 9 percent increase in BSE in offspring of BSE affected dams compared to calves born to dams where BSE was not 2
detected. Another study reported no evidence of disease transmission through embryos collected from cows with BSE.

What was the cause of BSE in Great Britain?
Data collected and analyzed suggest that animal feed containing contaminated meat and bone meal as a protein source. This was suspected to come from either scrapie sheep or cattle with an unidentified TSE. Changes in rendering practices in the late ‘70's and ‘80's may have
contributed to the causative agents surviving. Solvents thought to be a health risk to the rendering workers were banned and lower temperatures were used in processing the feed.. Experts now believe that these changes in the manufacturing techniques allowed a resilient strain of scrapie to enter the feed and for it to re-emerge in a new form in cattle disease - BSE.

Are there similar diseases in humans and other animals?
BSE belongs to the family of diseases known as transmissible spongiform
encephalopathies (TSE). TSE’s are caused by agents which usually produce spongiform change in the brain. TSE”s include scrapie, which affects sheep and goats, transmissible mink encephalopathy, feline spongiform encephalopathy, chronic wasting disease of deer and elk and in humans, Kuru, Classical Creutzfeld-Jacob Disease (CJD), Gertsmann-Straussler Syndrome, fatal familial insomnia and v CJD. TSE’s found in the United States include: Scrapie in sheep and goats, transmissible mink encephalopathy and chronic wasting disease of deer and elk.
Following are questions concerning the discovery of the BSE cow found in Washington.

What was the source of the animal that was found to have BSE?
The cull dairy cow, a Holstein; came from a dairy farm near Yakoma, Washington. Later, December 26, information revealed the cow was born in Canada and was 6 ½ years old. This is important. If the cow was 6 years old or more, she may have consumed feed that contained nervous system tissue before the regulations in Canada went into effect that prohibited
feeding feed that would contain brain and spinal column tissue. It was confirmed (12-29-03) that the animal was older than first thought and could have consumed feed that contained tissue residue that causes BSE before it was halted by regulations

How did the animal get into the United States?
Records that were available indicated that the animal came into the U.S. from Canada in August 2001 via Eastport, Idaho, port along with 73 other dairy cows from a herd in southern Alberta. It is likely that the other 73 cattle are still alive and will be located and tested.

What is the likelihood of the remaining 73 animals being infected?
It is thought to be low. Even in England at the height of the BSE situation, the usual incidence of BSE within a particular herd was no more than one or two animals.

What about the remaining dairy cattle in the herd from which the animal was culled, will they be depopulated?
A decision has not been made. A study of the situation will be made and a
recommendation will be made on cattle, if any that need to be depopulated.

Is the discovery of BSE terrorist related?
NO! There is no indication that the discovery of BSE is related to any terrorist activity. The only way that the disease can be spread is by the consumption of contaminated feed. It requires from 2 to 8 years for the disease to be incubated.

Are dairy cows more likely to have BSE than “beef cows?”
Most of the cases in Great Britain have occurred in dairy cows between 3 and 6 years of age. The cow discovered in Washington to have BSE was also a Holstein. The breed of the other Canadian cow that was discovered to have BSE last summer was not identified. The number of cases in dairy cattle can not be attributed to the cattle being dairy. The prevalence of disease in dairy cattle may be a result of feeding concentrate rations to the dairy cattle compared to “beef cows” rations consisting of forages and limited supplements.

Is beef safe to eat?
Consumers should feel, with confidence, that it is safe to eat beef. All science shows that the BSE infectious agent has never been found in the muscle tissue of beef products or milk and U.S. beef is safe to eat. Americans can be confident in the safety of U.S. beef for several reasons:
• The BSE causative agent is not found in the meat like steaks and roasts. It is found in the central nervous system tissue such as the brain and spinal cord. Brain and spinal cord tissue are not included in food products.
• All U. S. cattle are inspected by a USDA inspector or veterinarian before going to slaughter and the meat products going into the food chain. Cattle with any signs of neurological disorders are tested for BSE. This method worked and resulted in testing of the cow and discovery of BSE in Washington.
• BSE affects older cattle, those over 30 months of age. The Holstein cow from Washington state was thought to be 6 years of age. Records from Canada indicated that the animal was 6 years old, at least. The vast majority of U.S. cattle going to slaughter for beef consumption are under 24 months of age. An exception to this, of course, is the marketing of cull beef breeding stock and dairy animals.
• The U.S. began a surveillance program for BSE in 1990. The U.S. was also the first country without BSE to test cattle for the disease. As previously states, all cattle are tested that show signs of neurological disorders as well as those over 30 months of age that are not ambulatory. Locating this cow was the result of the surveillance program. In 2003, USDA tested 20, 556 brain samples which was triple the number in 2002.
• In summary, the is no scientific evidence to support that meat,milk and dairy products carry the agent that causes BSE.
• People can possibly contract a form of BSE (CJD) if they consume infected nerve tissue, the brain and spinal column. The human form of BSE resulted in death of 143 people in Great Britain and 10 elsewhere, non in the United States.

Does the U.S. import cattle semen and embryos from BSE affected countries?
Yes. All bulls producing semen for export to the U.S. are required to meet all 5 of the following conditions: 1. Semen donor has not been on the premises where BSE has occurred within 5 years of the date of embryo or semen collection, 2. Semen donor is not infected with BSE, 3. No progeny of the semen donor is affected with BSE, 4. The parents of the semen donor
are not affected with BSE, 5. The semen donor has not been fed ruminant derived protein.

What is the incidence of CJD in the United States and the rest of the world?
About 1 case per million population per year.

What will be the impact of the case of BSE on the nation’s and state’s beef industry?
As you are aware, the stock of McDonald’s, Wendy’s and Tyson Foods fell 5 to 7 percent Christmas Eve and the futures market went down the limit before and after Christmas. The stock of these companies improved 0.4 to 1.6 percent today (12-29-03). Futures went down the limit
again today, December 29. Also, approximately a dozen countries halted the importing of U.S. beef. The export of beef and beef products amount to around 10 percent of the U.S. annual production. Currently, consumer reaction appears to not be strongly negative. Of course, this could change if other cases occur here in the United States. This will be a “wait and see”
situation.

USDA will probably evaluate its current program in regard to BSE. This would include the surveillance program in terms of increasing testing. Another factor that is being considered is the modification of its policy to specify that product from downer animals that are tested would be held until test results are available.

Another item that is going to receive increased attention is the enacting of a national identification system for individual cattle as well as premise identification. These may be put into effect more rapid that anticipated. USDA will probably dictate the system.

Most are concerned about the impact on prices of Tennessee feeder cattle. With the fat futures market declining, the price for feeder cattle can expect to also decline. With the holidays, few sales have been held the past 10 days or so and it will probably be after the first of the year before an impact on prices can be determined. However, it is anticipated that prices will continue to decline up to about 30 percent from prior BSE discovery. There is really no foundation for this statement, except the declining future prices and “gut feeling.” Again, if other cases turn up, it could be a “fast, wild ride.”

The main thing to emphasis to consumers is that the U.S. Beef Industry is producing a safe, wholesome, food product and beef is safe to eat.

To producers, emphasize that the beef industry is “consumer driven” and need to keep that in mind. We need to continue to maintain production programs that result in a positive consumer perception.

Prepared by James B. Neel, Professor of Animal Science (12-29-03).

Source: Reports from USDA and National Cattlemans Beef Association.