BVD

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BVD

• Colorados Voluntary BVD Control Program

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Bovine Viral Diarrhea (BVD) review

• BVD may infect cattle of any age.
• BVD is a disease that diminishes production and
  in the individual impacts multiple body systems
  including the reproductive, respiratory,
  digestive and immune systems.
• Clinical signs can vary from pneumonia,
  abortions, stunted calves, stillbirths, PI
  calves, weak calves, unthriftiness, increase
  disease susceptibility and full blown disease
  characterized by a watery diarrhea that
  frequently leads to death.

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BVD types

• The virus presents in different forms,
  cytopathic, noncytopathic, type 1, type 2, type
  1a, 1b, 2a, 2b..etc., etc., etc.
• All of this makes for confusion when selecting
  vaccines and testing for the disease.
• The virus may exist in multiple species and
  transmission from one to the other may occur

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Transmission and Sources of BVD

• Transmitted by, ingestion, inhalation, insects,
  carried on boots and vehicles
• Sources
• transient infected animals including wildlife
• Persistently infected animals are the main source
  of infection. PIs shed viruses in high numbers
  and infect others, even if they are vaccinated.
• PI calves result from the dam being exposed
  during the first third of pregnancy

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BVD INFECTION DURING GESTATION
infertility
congenital defects
repeat breeding
immune response
d 0
d 283
d 125
d 150
d 58
d 90
persistent infection
abortion, stillbirth
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Keys to controlling BVD

• Understand persistently infected (PI) animals
  as they relate to BVD.
• Not be willing to live with one or more PI calves
  in a herd.
• Not be willing to keep a PI calf as a replacement
  heifer or breeding bull. (dont sell them either)
• Commit to finding BVD PI cattle in the herd

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Can you pick out the PI calf?
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BVD Review

• BVD can cause a variety of clinical and
  subclinical reproductive, enteric, and
  respiratory syndromes and immune suppression.
• BVD is unique in that a fetus that is infected
  from its transiently or persistently viremic dam
  prior to formation of a competent immune system
  can become persistently infected (PI) with the
  virus.
• PI animals will shed BVD from body secretions
  throughout their life.
• PI animals are considered the primary reservoir
  for BVD in both cow herd and feedlot situations.

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BVD Review (continued)

• A current estimate is that about 10 of beef cow
  herds have at least 1 PI animal, and about 0.25
  to 1 of calves born are PI.
• Veterinarians/Producers should have a
  surveillance strategy to determine level of herd
  risk for the presence of PI animals (High vs. Low
  Risk).
• Herds that are considered high risk for
  containing PI animals should utilize laboratory
  tests to do whole-herd screening to find all PI
  animals and then remove them.

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Financial impact of BVD

• 10.00 to 24.00 per breeding animal
  (conservative estimate based on value of the cow
  and the lowered calf crop) a 200 head cow herd
  would lose 2000 to 4800 per year.
• In the feedlot economic impact can be
  tremendous.21,000 to 100,000 have been lost in
  a few weeks by local feedlots.

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Colorados BVD Program

• Colorados BVD program is strictly voluntary
• What will the program do
• Improve reproductive performance
• Improve calf performance
• Lower treatment costs
• Lower death loss
• Provide a more marketable commodity

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BVD PI Myth 1

• PI calves will be killed by MLV vaccination
• Fact Controlled experiments have not been able
  to induce morbidity or mortality in PI calves
  following MLV vaccination. However, case reports
  indicate that MLV vaccination can cause a PI
  animal to become moribund or to die - though far
  less than 100 are negatively affected..

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BVD PI Myth 2

• PI calves will be thin, have a rough haircoat,
  and be a poor-doer
• Fact While many PI animals are unthrifty,
  reports have indicated up to 50 will appear
  normal and may enter the breeding herd or feedlot
  pen in excellent condition. PI calves cannot be
  identified visually.

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BVD PI Myth 3

• Calves are PI because their dam is PI
• Fact Recent research has shown that 7 of PI
  calves dams were PI, the other 93 of calves
  have dams with a normal immune response to BVDv
  and are not persistently infected.

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BVD PI Myth 4

• The greatest cost associated with a PI calf is
  the death of that calf
• Fact The reproductive loss associated with
  lower pregnancy proportions, more abortions, and
  higher calf mortality are the greatest economic
  costs of exposure to PI animals. In addition,
  increased morbidity, treatment costs, treatment
  failure, and reduced gain in feedlot or stocker
  pen mates greatly exceed the cost of PI death in
  feeder cattle.

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BVD PI Myth 5

• BVDv problems will always be obvious
• Fact If BVDv was introduced into the herd via a
  PI animal several years previously, after an
  initial period of noticeable losses, the herd may
  currently experience only low reproductive loss
  and BVDv-associated morbidity. This low loss
  however, may not be compatible with economic
  sustainability.

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BVD PI Myth 6

• BVD wont affect my herd because I vaccinate
• Fact The tremendous amount of virus secreted by
  a PI calf can overwhelm a level of immunity that
  is protective under less severe exposure. There
  are documented cases of herds with vaccination
  protocols in place for several years that have
  endemic BVDv because of the presence of PI
  animals.
• VACCINATION ALONE WILL NOT SOLVE BVDv PROBLEMS

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Thats all Ive got to say!!!