EPDS III - Demonstrating the impacts of Campylobacter vaccination in maiden ewes

Summary

The aim of this Enhanced Producer Demonstration Site project, in partnership with Agriculture Victoria is to conduct a vaccination trial for campylobacter to assess if reproductive outcomes in maiden ewes in the Campaspe region can be improved.

The outcomes to be assessed and improved upon in maiden ewes include an increased number of foetuses present at scanning, decreased percentage of empty ewes at scanning, increased lamb survival rate and reduced abortive/stillborn events in the control vs treatment group.

Objectives

1. To investigate prevalence of campylobacter in maiden ewes in the Campaspe region. This will be carried out by conducting serosurveillance testing on maiden ewes and by submitting suitable postmortem samples from abortion/still born events. This will be investigated over ideally three lambing seasons to assess exposure over time as well as on different farms in the area to collect representative information.
2. Increase awareness of campylobacter infection through vaccination adoption. Awareness will be created through presentation of prior research, results from this demonstration, guest speaker sessions as well as reflection of ewe serology and lamb postmortem results. Campylobacter has often been thought as a high rainfall issue and this project will assess its presence in a lower rainfall region to assess possible reasons for suboptimal reproduction performances.

Progress

Three farms in the Campaspe region investigated the incidence of Campylobacteriosis in their young pregnant ewes in the first year of a three-year Enhanced Producer Demonstration Site, managed by Rochester vets and Agriculture Victoria with funding from MLA and Agriculture Victoria. The results from year 1 showed no exposure to Campylobacteriosis in the unvaccinated maiden ewes.

There were differences seen in the scanning and marking results between unvaccinated and vaccinated ewes with increased scanning and marking percentages in the vaccinated compared to the control groups observed in 2 out of the 3 sites but these were likely due to nutritional and environmental factors. As the unvaccinated ewes in the trial were young and had had less time and fewer opportunities for natural exposure encountered Campylobacter (ewe lambs or maiden), they would be at increased risk of having an abortion storm if they were to come in contact with the bacteria when pregnant.

The vaccinated ewes however become protected from Campylobacteriosis during lambing, and have reduced risks of abortion storms which can be catastrophic. The results highlight the importance of producers managing younger sheep and older sheep separately from joining onwards to help reduce this risk if they are not vaccinating against campylobacter.

Going into year 2 of the demonstration, the farmer group decided to focus on other aspects of sheep reproduction. As many farmers join ewes in late Spring (Oct/Nov) for an autumn lambing, Regulin will be trialed to bring ewes and rams into season for early joining. The demo, however, will continue to monitor for Campylobacteriosis by undertaking paired blood samples at risk times in maiden ewes.