The number of newborn lambs that survive to weaning is the single biggest driver of profitability on most sheep farms in NZ (fine wool farms being the obvious exception). Yet, so often, we leave the outcome to chance, and we fail to protect our investment by neglecting to use the very good available sheep performance vaccines properly and to their full potential. Sheep performance vaccines include Campyvax4®, Toxovax® and salmonella vaccine. While the latter two vaccines are generally strictly adhered to in terms of label application, we appear to be underutilising the benefits that Campyvax4® can bring to the table.
Studies have shown that, despite vaccinating maiden ewes with Campyvax4®, over half of the mixed-age ewes are naïve to the bacteria, making them at risk of losing valuable lambs. Historically, following the initial vaccination course in maiden ewes or hoggets, we have relied on environmental pressure to continue to stimulate immunity.
Why do we do this?
It is time to rethink how you go about using vaccination to ensure that you cover your whole flock, and it might be advisable to introduce a third shot and maybe an annual booster (as per the label recommendation of Campyvax4®).
A recent field study in Hawkes Bay revealed a 4% improvement in lambing percentage for two-tooths that were given a third booster shot after their primary course as hoggets, compared to the two-tooths that were not boostered (134% vs 130% or, in other words, 40 extra lambs per 1,000 ewes). Given a value of around $100/lamb, that equates to an extra $3,300 over and above factoring in 2% lamb losses and the cost of vaccine.
While actual trial work is limited, there is plenty of anecdotal evidence of farmers seeing lifts in lambing percentage when undertaking additional boosters in their mixed-age ewes. Farmers undertaking this strategy report seeing fewer slipped lambs before lambing, and, overall, more lambs born that are ready to thrive. Campylobacter is capable of causing losses on farms between lambing and tailing without seeing any abortions. Abortion storms appear to be an event of the past (in vaccinated flocks), but insidious losses will continue to eat away at profits.
NZ sheep farmers are challenged, like their dairy counterparts, to become more efficient and reduce wastage in their flocks as a step to reducing greenhouse gas production. Maximising lambing potential goes a long way to achieving that aim, and repeated boosters of Campyvax4®, along with the use of other sheep performance vaccines such as Toxovax® and salmonella vaccine, are all simple tools to maximise lamb production and hence profitability. Talk to your Vetlife veterinarian about the sheep production vaccines that can support your flock’s wellbeing and improve your profit margins.