Are your rams negative for ovine brucellosis?
As we head into ram buying season, are you confident you have the information you need to avoid bringing home a ram with ovine brucellosis?
Ovine brucellosis is a bacterial disease of rams which results in poor ram fertility, leading to poor lambing percentages. The disease is predominantly spread between rams through sexual activity and can affect any breed of ram.
The best time to check rams for ovine brucellosis is before they arrive on the farm, as stray rams and untested replacement rams are the most common causes of disease introduction.
Producers should not just rely on a lack of visible or palpable abnormalities in the testes for assurance that rams are uninfected when buying in rams. Infected ram testes can look normal and animals will not appear sick.
When purchasing rams, producers should buy rams from a flock accredited under the WA Ovine Brucellosis Accreditation Scheme (OBAS).
Accredited producers must have regular negative test results for their flock and demonstrate good biosecurity practices.
Another option is for buyers to request two negative blood test results for ovine brucellosis 60 days apart before buying.
If testing is not done before the rams arrive, they should be isolated on arrival and have two blood tests 60 days apart with negative results before mixing with other stock.
Ewes that have recently been served by infected rams can also spread the disease to clean rams if they are served in the same oestrus cycle, so ewe introductions should not be joined for a minimum of four months to ensure they are no longer infective.
Prevention is best in the case of ovine brucellosis: it is expensive to eradicate as there is no vaccine for the disease and affected animals should be culled.
For more information about preventing ovine brucellosis and the OBAS, see the ovine brucellosis webpage, or contact Department of Primary Industries and Regional Development veterinary officer Kristine Rayner on +61 (0)8 9821 3248 or email obas@agric.wa.gov.au.