tuberculosis, leukosis, IBR (q. 13 - 16)

Question 1

definition of tuberculosis free bovine herd

Answer 1

⚫ No clinical signs (min 12 months)
⚫ All animals over 6 weeks: two official intradermal
tuberculin tests
⚫ 1st: 6 months after the removal of infected animals,
2 nd: 6-12 months months later;
⚫ Animals introduced: from officially free herds or
tested (within 30 days)
⚫ Meat inspection, lesions: compulsory investigation
⚫ (Two)yearly tuberculin testing of all animals over
12 months
⚫ General measures (isolation of the holding, record of comp. laboratory examinations, control of movements of visitors, animals, vehicles, control of dogs and cats on the holding etc.)

Question 2

definition of officially enzootic bovine leukosis free herd

Answer 2

1. there is no evidence, either clinical or as a result of a laboratory test, of any case of enzootic bovine leukosis in the herd and no such case has been confirmed in the previous 24 months;
   and
2. all animals over 24 months of age have reacted negatively during the preceding 12 months to two tests carried out at an interval of at least 4 months; and
3. any animals introduced into the herd
   ⚫ come from an officially enzootic bovine-leukosis-free herd or
   ⚫ originate from establishments where there has been no evidence of EBL within the
   24 months prior to their dispatch; and
   – all animals over 24 months of age reacted negatively to a test on two occasions at an interval of not less than 4 months while kept in isolation; or have been subjected to a
   serological test, with a negative result, within 30 days prior to their introduction
   – all animals less than 24 months of age were born to dams, that have been subjected to a serological test for EBL, with negative results, carried out on samples taken during the past 12 months on two occasions at an interval of not less than 4 months
4. all germinal products of bovine animals introduced into the establishment originate from establishments free from EBL; or from an approved germinal product establishments

Question 3

definition of IBR-virus free bovine herd (the answer changed, he changed the lecture in 2022)

Answer 3

⚫ during the past 12 months there has been no confirmed case of IBR/IPV in bovine animals kept in the establishment
⚫ during the past 2 years none of the bovine animals kept in the establishment has been vaccinated against IBR/IPV

serological tests (BoHV-1-gE, if vaccinated before):
⚫ a blood, milk or meat juice sample taken from each bovine animal over a period of not more than 12 months; or
⚫ blood, milk or meat juice samples taken on at least two occasions at an interval of 2 -12 months from
– all female bovine animals over 12 months of age (could be bulk milk samples taken on at least 3 occasions at intervals of not less than 3 months) , and – all male bovine animals used or intended for breeding over 12 months of age, and – a random sample of male animals not intended for breeding over 12 months of age.
⚫ all bovine animals introduced into the establishment originate from establishments free from IBR/IPV and have tested negative in a serological test or have been subjected to quarantine prior to their introduction and have tested negative in serological test
⚫ all germinal products of bovine animals introduced into the establishment originate from establishments free from IBR/IPV; or approved germinal product establishments

Question 4

maintenance of IBR-virus free status in bovine herd

Answer 4

• All animals above 6 months of age: tested every 12 months
• Animals for slaughter: test before transport for slaughter
• Dairy herd: milk test in every 6 months
• Aborted animals: test 3-6 weeks after abortion
• Only animals from free herds are introduced (test: 2x, 21 days’ interval)