Johnes Disease

Johnes is an infectious bacterial disease that affects cattle which may often go undetected but has a serious and detrimental effect on herd health.

30 July 2014

Each supplier has the option of joining the Carbery Johnes Programme for 2014. Participants in the scheme will need to carry out an individual Johnes test on all adult females through milk or blood samples and also have a risk assessment carried out by their vet.

Suppliers can arrange a blood test with their own vet or through the Department if they are due a brucellosis test. Alternatively the herd can be screened by milk samples if it is part of the milk recording scheme.

Carbery are encouraging all suppliers to take up one of the options and will pay a subsidy of €100 per herd to assist in covering the cost.

Participants in the AHI national pilot programme must as a condition of the programme carry out individual Johnes tests and should sign up for the Carbery scheme in order to avail of the €100 subsidy.

By participating in the Johnes programme, suppliers will gain valuable insight into the health status of their herd.

A Dairy Farmers experience with Johne’s Disease

As many dairy farmers throughout the country can testify, Johne’s Disease (JD) can be a crippling disease on any herd. For those who have been fortunate to escape its costs the disease implications are often overlooked. Over the past month, AHI has conducted a number of interviews with farmers who have suffered at the hands of JD to show the true expense of this disease in an Irish context. Here is a Cork farmer’s experience with JD.

How did you first suspect you had JD in your herd?

A bull that was purchased 3 to 4 years previously started to get thin, despite eating normally. The bull also displayed scour symptoms and his signs kept reoccurring.

For how long do you believe the disease has been present in your herd?

As disease originated from bull, it must have been on farm for up to 4 years before diagnosis.

Did you have any clinical cases? If so, can you estimate the number and what symptoms you would have noticed?

Yes, once the bull was diagnosed he was removed from the herd for slaughter and he had been on farm for 4 years. Approximately 2 years after his removal a cow illustrated signs of clinical JD. A rigorous blood testing programme then commenced and this showed that a further 17 cows tested positive for JD. Once a positive test was shown these cows were dried off to ensure no milk entered the bulk tank. Interestingly, for one year, both milk and blood tests were conducted in the same year and very similar results ensued.

When did you first take action to tackle the disease? What measures did you put in place?

Once the first cow tested positive from the faecal examination, all cows were tested for JD. When it was discovered that a significant number were found positive we joined the AHI JD pilot programme. We subsequently implemented all of the risk management procedures that make up the disease management advisory visit (VRAMP)

What testing methods did you use?

Blood and milk tests

Were any other significant animal health problems identified in your herd over the period since you became aware that JD was present?

Tuberculosis also affected the herd during JD prevalence

Can you estimate the economic impact of JD on your farm?

Difficult to put exact estimate on it, but if you consider that over 20 animals had to be slaughtered and replacements had to be purchased to make up the difference, then the costs were considerable. (Unfortunately it was subsequently shown that some of the replacement stock purchased were also JD positive). The manpower involved to ensure that a new born calf is removed from its mother after calving is significant, plus you have to use milk replacer and ensure that calves don’t graze ground where adult cattle have been to eliminate risk.

Are you part of the AHI JD pilot programme? If so, have any changes been implemented to your management practices following the on-farm risk assessment conducted as part of that programme?

Yes, Stopped pooling milk after first cow was diagnosed. Only beestings used is from cows that are JD negative. Key one is removing calf from mother prior to birth to ensure no cross-contamination from mother’s faeces. I have also taken steps to ensure that grazing pasture for calves does not contain any slurry from cow population or any potential JD source.

What challenges have you experienced trying to control JD?

When first diagnosis was discovered, very little was known about JD and we continued as normal for a number of years. Without the control measures the disease spread and it created significant damage to my herd. The key to controlling JD is risk management, I can’t stress this enough, you have to get the calf away from her mother after calving if you have JD positive cows in your herd.

Can you say if the JD status of your herd has improved since you first began to take action to address the problem?


Have you noticed any changes to the general animal health status of your herd over the same period?

The current health status of my herd is very good. I think there is greater emphasis on calf rearing through the risk management programme and this is well worth it, despite the extra labour.

If you hadn’t taken action to tackle the disease when you did, what do you think would be the consequences for your herd now?

If I didn’t take action when I did then the herd would have been depopulated.

Do you think you can completely clear JD from your herd? If so, how long do you think this might take?

Yes, we are 99% of the way there. It’s taken us the guts of 10 years.

Would you encourage other farmers to participate in the AHI JD control programme? (Please explain why/why not)

Yes, I would strongly encourage participation in the AHI JD control programme. Knowing when you have problems means you can deal with them before they become gigantic and possibly too late.

Do you have any advice for your processor or for AHI in relation to encouraging farmers to become actively involved in the AHI JD control programme?

I would encourage farmers to be proactive and don’t ignore symptoms. The follow-up management and risk assessment is critical.