Bovine Spongiform Encephalopathy BSE: A brief overview of the incidence and current protections in t

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Bovine Spongiform Encephalopathy (BSE)A brief
overview of the incidence and current protections
in the U.S.
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Bovine Spongiform Encephalopathy (BSE)

• BSE is a transmissible spongiform encephalopathy
• It is caused by a prion that creates holes in the
  brain
• These prions are located primarily in the brain
  and central nervous system
• BSE prions are thought to be mutations of the
  scrapie gene in sheep
• Evidence of genetically inherited resistance

Arrows Point to Holes in the Brain
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First Cases of BSE

• BSE was first found in Great Britain in 1986
• BSE is thought to be related to the sheep scrapie
  (a neurological disorder)
• The mutated form is similar to Creutzfeldt-Jakob
  Disease (CJD) and is termed variant CJD
• In all the cases and countries (30) reported
  there have been only 149 fatalities

Scrapie infected sheep
Countries reporting BSE
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Cause of BSE in Britain

• A combination of factors is thought to have
  caused BSE in rendering for meat and bone meal
• Meat and bone meal was more widely used in
  Britain than in the U.S. (10X)
• Scrapie infected sheep were rendered (about 1 in
  4 flocks have scrapie in Britain compared to 1 in
  100 in the U.S., primarily the Suffolk breed)
• British renderers lowered the temperature and
  pressure in response to energy costs

Staggering gait of BSE cow
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History of Preventing BSE in the U.S.

• US began testing for BSE in 1989
• All cattle imported from Europe were found,
  tested and slaughtered
• In 1997 Specified Offals Ban prohibited the use
  of ruminant by products in ruminant feeds (meat
  and bone meal)
• Brains and spinal cords (principal prion
  locations) are removed at slaughter

Ban has been in place since 1997
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How is BSE Transmitted?

• It is not transmitted from cow to cow or cows to
  humans but by cows eating ruminant byproducts
  containing infected nerve tissue
• In a risk management study conducted by Harvard,
  the likelihood of BSE from 10 infected cows is
  less than one additional case per year
• In addition, the virulence in humans may be 10 to
  10,000 times LESS

Non byproduct feed
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BSE in the U.S.

• A single incidence in a dairy cow was reported
  12/22/03
• She was a 6 ½ year old cow from Canada, most
  likely born before the specified offals ban was
  put into place in Canada
• She came to the US with 81 other head and she and
  11 others have been located
• Her bull calf and its herd mates were found,
  tested and euthanized

BSE infected cow in England
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Additions to Specified Risk Material List

• Skull, brain, trigeminal ganglia, eyes, vertebral
  column, spinal cord and dorsal root ganglia of
  cattle older than 30 months are banned
• Small intestine of all cattle
• Tonsils from all cattle are already considered
  inedible and banned
• Backbones of older cattle may be banned
• Other rules are being considered

Small intestines now banned
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New Rules Concerning Beef Cattle and Carcasses

• Downer cattle are banned from the food supply
• Cattle tested for BSE (20,000 per year) must be
  held for results
• Cattle in beef plants are being evaluated for age
  by teething to ensure their age is less than 30
  months
• Air injection stunning is prohibited
• Cattle testing for BSE will increase to 40,000
  head/yr

All cattle and carcasses are USDA inspected
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Effect on the Beef Industry

• The most dramatic effect was the closing of the
  export markets that represent 10 of carcass
  value and production
• Fed cattle prices dropped 20/cwt and calf and
  cow prices were lower as well
• Fortunately beef demand is up and production is
  down (lighter carcass weights and fewer cattle
  slaughtered) so the effect in the short term is
  less severe

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Summary

• Only one dairy cow (originally from Canada) has
  been diagnosed with BSE (Canada has had 2 other
  cases), there are NO other cases in the U.S.
• The safeguards that have been in place since 1997
  have been bolstered to ensure U.S. beef remains
  BSE free
• The risk of contracting the disease by other
  cattle or having it transmitted to humans is
  extremely low
• Because of lowered beef production and improved
  demand the effect of the closing of the export
  markets has hurt but not crippled our prices