Insist on BVD Tested and Vaccinated Bulls.

BVD, Bovine Viral Diarrhoea is a disease that affects cattle. Exposure in NZ is high and it is easily passed on both through direct contact with infected animals and indirectly via yards, transportation and footwear.

If a cow is exposed to the BVD virus for the first time during mating or pregnancy, the outcome for her and her calf depends on the stage of the pregnancy that exposure occurred and may be any of the following:

  • Failure to conceive
  • Aborted pregnancies
  • Stunted / deformed calves
  • Calves born Persistently Infected (PI’s)

PI (Persistently Infected) animals carry the disease throughout their lives, infecting naive animals that they come in contact with, without necessarily showing any signs of illness themselves.

TI (Transiently Infected) animals have the disease and will recover, but are temporarily contagious while sick. They too will spread the disease.

We do not recommend the use of bulls that have not been tested and vaccinated against BVD. All bulls should be tested for BVD and if negative should receive an initial vaccinating programme consisting of a sensitizer and booster vaccination. An annual booster vaccination is then required annually prior to mating. Certification should be viewed prior to buying or borrowing bulls for mating. Insist on seeing the vet certificate that states both testing and vaccinating has occurred.

Bulls that test negative should still be vaccinated to protect them from infection when entering the herd. If a naive bull becomes transiently infected upon entering the herd there is a good chance his sperm will be ineffective for around three weeks, and he will infect every cow he comes in contact with during that time. Vaccinating bulls not only protects the herd from him but also him from the herd.

Talk to vet for more information on the disease and vaccination strategies.