Sheep producers are being urged to be aware of Campylobacter, a common bacteria which is a leading cause of infectious abortions across the country.
Veterinarians are advising producers the vaccination of their breeding ewes will protect their flocks and ensure more lambs will be born and so improve the overall profitability of the sheep industry.
Dr Jim Walsh, veterinarian and technical adviser at Coopers Animal Health pointed out lamb losses from Campylobacter vary from region to region, but low-level losses have occurred across many farms in NSW and particularly in maidens.
"Farmers have come to accept that maidens will have lower lambing rates than older ewes but it doesn't have to be the case with good management and prevention," Dr Walsh said.
"I encourage all producers to consider the risks associated with not vaccinating and to be aware that some flock management practices increase the likelihood of infection."
The bacteria is spread through faeces, urine and aborted foetuses and obviously through dry periods when pregnant ewes are being fed along trails or in containment lots the risk is higher.
Contaminated pastures is another source of infection as the bacteria is ingested by ewes which would have been otherwise not infected.
"Infected ewes appear healthy and productive and may only show signs of Campylobacter when they don't produce a lamb," Dr Walsh said.
"Intensive grazing of pregnant ewes in cells could also lead to infection as does the introduction of ewes to the farm."
It has long been thought Campylobacter was only prevalent among flocks grazing in the cool and high rainfall areas; however increasing number of infections is being noted in the drier, mixed farming and pastoral regions.
"It has always been in those dry areas but because sheep are now worth more, producers are taking more notice of their ewes," Dr Walsh said.
"It has also been exacerbated through supplementary feeding along trails or in containment lots through these droughts."
Dr Walsh advises producers consult their veterinarian if they have concerns but suggested those ewes which have not ever been vaccinated are given two vaccinations prior to joining.
"An annual booster vaccination before joining is also advisable if you consider there is risk, especially if you are joining in containment lots."
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