SHEEP FARMERS in Morayshire have come together to gain a better understanding of the fatal viral lung tumour ovine pulmonary adenocarcinoma (OPA), with a view to decreasing transmission, and increasing the profitability and productivity of their flocks.

The project, which started as a Rural Innovation Support Service group supported by SAC Consulting, examined the true impact of OPA, which is predominantly spread between sheep via nasal and oral secretions.

Laura Henderson, a qualified vet and agricultural consultant with SAC Consulting who coordinated the group, said: “In early 2020, I was asked to go to the Aberlour and District Agricultural Discussion Group to speak on OPA. One of the farmers at the meeting had started scanning his flock and during the meeting there was lively discussion and interest in the topic.

“Unfortunately, many farmers are either not aware of the disease or fail to admit their flock is affected by OPA and, currently, the only diagnostic test available for live sheep is ultrasound scanning of lungs by a vet, but none of the local vets offer this service yet," said Ms Henderson.

“The disease has a significant impact on animal health and welfare of affected sheep and can also cause a considerable financial impact on affected farms due to increased cull rates, fallen stock disposal and increased need to purchase replacement stock.”

The project, which ran from July to December last year, consisted of monthly meetings with an aim to increase farmers’ understanding of the risk factors for OPA spread, raise awareness of the disease with other local farmers and work with the vets to start offering this service.

“There can be a stigma attached to admitting the presence of OPA in your flock, but the farmers who attended the meetings saw the importance of sharing their experiences, and those that were already scanning their sheep for the disease presented their results and what control measures they had implemented,” she said.

Throughout the project, the group welcomed guest speakers from the Moredun Institute to discuss the latest research as well as farmers from outside of the local district who shared how they have integrated scanning into their system.

Michael McGillivray from Auchnascraw, who farms 1200 breeding ewes, 250 mule ewes in-by and 950 hill Blackface ewes, participated in the project and said that farmer-to-farmer knowledge exchange was an important catalyst for others in the group to start scanning their sheep.

Mr McGillivary said: “We have a closed female breeding flock except for the new shearling tups we buy in and, subsequently, started losing a percentage of tups each year and we suspected could be down to OPA.

“We started scanning in October after attending the RISS group meetings because we wanted to nip it in the bud before you end up with a big problem.

“Our sheep go to the hill all summer and they are a hefted flock so if we lose sheep out of this flock, it’s not easy to go to market and replace them as they’re not hefted to that hill," he explained.

“OPA is something that is quietly spoken about in the Blackface sheep groups and there is a fear of scanning because if someone hears that they’re doing it there will be a perception that they have a problem. But, if you scan and get accredited for having a clean flock, I know we would be more likely to buy new breeding stock that were actively whole flock scanning for OPA as a preventative measure.”

Although the formal RISS project has now finished, those involved are keen to continue working together and encourage more farmers to start scanning their flocks.

Ms Henderson continued: “Looking to the future, the group would like to gather more data which can demonstrate the economic cost of OPA in sheep based on flock performance, and in partnership with other research institutes, we can promote the benefits of OPA control to the wider industry.

“Ultimately, the group would like to see the exploration of an accreditation scheme for flocks that are scanning for OPA as it is most commonly introduced to flocks via the purchase of infected individuals.”