Q&A: A dairy farmer’s experience with Johne’s Disease

For those who have been fortunate to escape its costs, the disease implications are often overlooked.

Over the past few months, Animal Health Ireland (AHI) have conducted 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 three to four years previously started to get thin, despite eating normally. He also began to scour intermittently.

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

As the disease originated from the purchased bull, it must have been on the farm for around four 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.

Approximately two years after his removal, a cow started to show signs of clinical JD.

A rigorous blood testing programme then commenced, and this revealed a further 17 cows that tested positive for Johne’s Disease.

These cows were dried off to ensure no milk entered the bulk tank. Interestingly, during one year, both milk and blood tests were conducted with very similar results.

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

The first cow that tested positive was confirmed using a faecal test. Following that, all cows were tested for JD. When it was discovered that a significant number were positive, we joined the AHI JD pilot programme.

We subsequently implemented all of the risk management procedures recommended to us, following the on-farm risk assessment management plan which was conducted by our vet.

What testing methods did you use?

Blood and milk tests.

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

Tuberculosis has also affected the herd.

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

It’s difficult to put an 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 subsquently 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, we stopped pooling milk after the first cow was diagnosed. The only colostrum used is from cows that are Johne’s Disease negative.

A key change has been the removal of calves from their mothers directly after birth, to ensure no exposure of calves to adult cow faeces. I have also taken steps to ensure grazing pasture for calves does not contain any slurry from the cow population, or any potential Johne’s Disease source.

What challenges did you experience trying to control JD?

When JD was first diagnosed, very little was known about Johne’s Disease, and we continued as normal for a number of years.

Without 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, and you have to get the calf away from her mother after calving, if you have JD positive cows.

Has the Johne’s Disease status of your herd improved since you first addressed the problem?

Absolutely.

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 on-farm risk assessment management plan and this is well worth it, despite 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?

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?

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

Would you encourage other farmers to participate in the AHI JD control programme?

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 on 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 are critical.

What is your final advice?

If there is one thing I have to emphasise, it is the removal of the calf from the cow directly after calving, I can’t stress this enough.

Furthermore, if you want to alleviate the risk of JD entering or spreading in your herd, the new born calf needs to be separated from adult cattle for as long as possible, I would recommend a year.

If you think JD might be in your herd, you need to rear calves with milk replacer.

As the animal gets older the risk diminishes. Finally, I would say that JD in your herd is not an insurmountable challenge, if you deal with it head on in an effective and systematic manner.