Infected bulls pose VDrisk
HERD conception rates may be devastated and could fall as low as 20% by introducing a bull infected with the venereal disease Campylobacter.
Colin Penny of the Royal Dick Vet School, Edinburgh, warns that this disease is becoming more common as more producers are sharing bulls or hiring sweeper bulls to use after AI.
"The first signs are cows coming back into season after they are served," he says. "Cows will build up a natural immunity to Campylobacter and get in calf once they have cleared the infection after three or more services – but this will extend the calving pattern." Once the infection is identified, Mr Penny advises starting AI to stop it spreading.
Infected bulls are difficult to treat, he warns. Sheath washing with antibiotics can be successful, but it is safer to cull these animals.
To help control the disease avoid hiring bulls, he says. When a bull must be hired check its history and have his sheath washed before use.n