Sharing hired bulls increases VD risk
THERE could be an increased risk of herds contracting venereal diseases (VD) when a hired bull is shared between different farms, warns Mike McGowan of the Royal Vet College.
There is increasing recognition that VDs, such as campylobacter, are increasing and one reason could be the practice of leasing in bulls which risks poor biosecurity, he says. "These bulls could also spread other diseases, including infectious bovine rhinotracheitis, Johnes, leptospirosis and bovine virus diarrhoea."
To prevent VD infection, bulls used in a herd should ideally be virgins. But bulls younger than three years old are less likely to be harbouring campylobacter than older bulls.
"When older bulls are leased in, they must be tested for disease and/or treated with a precautionary antibiotic sheath wash before use," advises Prof McGowan. *