But after 11 years of regular testing and careful management, they’ve reduced prevalence in their Southland herd from 7.2% to 2.4%. Their message to other farmers is to start by understanding your risk.
Alannah’s family have been aware of Johne’s disease for a long time. In the 1980s, her mother bought a cow that began losing condition and production. After the cow died, an autopsy confirmed Johne’s disease.
Fast forward to 2015, when Alannah noticed some of her own cows were lagging in production. She decided to investigate and tested all 400 cows in their pedigree Jersey herd through LIC’s Johne’s testing service. The first round of testing revealed positive results in more than 7% of the herd.
“The numbers were enough for us to realise we couldn’t just stick our heads in the sand. We needed to know what we were dealing with.”
Reducing the risk to young stock
Once the family understood the scale of the challenge, they focused on reducing the risk of young stock being exposed to Johne’s bacteria.
“During calving, we collect the calves from paddocks five or six times a day. If we can catch a calf before it has the chance to drink from its mother, we will.”
They also became more selective about which cows supplied colostrum to replacement calves. For many years, they avoided using colostrum from positive animals, as well as daughters and granddaughters of known positive cows. More recently, they invested in a colostrum pasteuriser and now pasteurise colostrum and transition milk before feeding young stock.
One purchase can undo years of progress
As pedigree Jersey breeders, the family occasionally buy cows to strengthen genetics and replace animals lost through culling. But some purchased bloodlines later contributed to Johne’s-positive animals appearing in the herd.
The experience changed how they approach buying stock. They now place much greater emphasis on buying animals from herds with a long-term Johne’s testing history – something their own years of LIC testing have shown the value of.
The tough decisions
One of the hardest parts of managing Johne’s has been culling cows that still appear healthy.
“We love our cows. They’re part of our family, but the reality is they have to go.”
In the early years, the family sometimes had to cull large numbers of cows, with a significant emotional and financial cost. Today, Johne’s no longer dominates every culling decision. Alannah says while Johne’s can feel overwhelming, doing something is always better than doing nothing.
“We didn’t do everything at once. What’s important is to start by doing the things you can. It’ll make a difference.”
What does Johne’s risk look like on your farm?
LIC’s Johne’s testing can help you understand your herd’s risk and track progress over time. Use this checklist to get a quick picture of where your farm could be exposed.
If your score is above 2, talk to your vet about the risks on your farm and what steps you can take to reduce them.
