Johne's testing - cost or saving?

Cow with Johne's disease

Around 50% of herds in NZ are thought to be infected with Johne's. Do you know your herd's status?

Johne's can be an elusive disease. Calves become infected with the Johne's bacterium MAP, typically at less than 6 months of age. The disease remains hidden for several years with animals not generally testing positive until they are at least 2 years of age.

By the time you see a scouring cow in the herd the disease has already cost you money:

  • Clinical cows end up being euthanased and sent to pet foods
  • Cows will have been shedding MAP in faeces, colostrum and milk and likely infecting recently born calves in your herd
  • Some cases may be super shedders, significantly amplifying the new infection rate.

Testing every cow at herd test time with a milk antibody test through LIC (cost approx. $5.50 per head) means you can identify infected cows before they lose weight and scour. These animals can therefore be sold for cull cow value. In many herds, the offset of cows sent for slaughter vs sent to pet foods covers the cost of testing.

Removing infected animals before they start shedding MAP bacteria in large numbers, in conjunction with developing a Johnes control plan with your vet is the best way to reduce the incidence of Jones in your herd over time.

LIC have also released a Johne's effluent PCR screen. If you are unsure of your herd's status, this could be a useful tool to confirm a positive Johnes status.

Now is a great time to start thinking about Johne’s control in your herd- pick up the phone and chat to your vet today!

Dr Jason Fayers BVM&S CertCHP (Cattle Health & Productivity)