|
Disease
Facts
-
Blood borne disease caused by bovine leukosis virus
-
88.5% of dairy herds and 38.7% of beef herds are infected
(NAHMS ’96 survey)
-
Clinical symptoms (caused by tumors in 5% of animals
infected) include: weight loss, decreased milk production and immobility
(downer cows)
-
Leukosis tumors are the leading cause of condemnation
at slaughter facilities
-
Disease is spread by transfer of blood cells from
infected animals via:
-
re-use of contaminated needles, syringes, breeding
sleeves, dehorners, tail dockers, milking equipment, hoof knives,
etc.
-
colostrum and waste milk
-
transmission to fetus in utero (10 – 20%
of the time)
-
Costs of BLV are typically associated with lost marketing
opportunities: sale of replacement stock, bulls to A.I. or embryos
-
There is no treatment for the disease, so symptoms
get progressively worse until the animal is culled from the herd or
dies
How
to control the spread:
-
Use needles and breeding gloves once then discard
-
Disinfect all instruments used for management procedures
before re-use, including: dehorning, castration, tagging, tattooing,
etc.
-
Use Artificial Insemination or BLV-negative bulls
-
Feed calves colostrum from BLV-negative cows or use
milk-replacer
-
Clean calf delivery equipment and maternity area after
each use
-
Reduce contamination by cleaning feed and water containers
regularly
-
Manage positive and negative cows in separate groups,
if possible
-
Milk and perform veterinary procedures on BLV-positive
animals last
-
Eliminate overcrowding (no more than 110% in freestall
barns)
-
Reduce numbers of biting insect
|
