Preventing the spread of bovine Johne's disease in cattle

Why control bovine Johne’s disease?

Bovine Johne’s disease (BJD) is an invariably fatal disease of cattle, goats, deer and camelids that is not currently widespread in Australia, and we want to keep it that way! Several factors make BJD easier to control than ovine Johne’s disease (OJD).

Rationale used for controlling the spread of BJD

• Older cattle are resistant to infection.
• Infected cattle under 2 years of age rarely shed the bacteria, and so are not infectious.
• Calves younger than 30 days are most susceptible.
• Young cattle can still pick up the disease, until they are about 12 months old.
• Spread is mainly by faecal contamination of any material consumed by cattle.
• Johne’s bacteria can survive for long periods while moisture is present.
• Johne’s bacteria will die out in hot, dry conditions.
• The disease is far more common in dairy cattle than beef cattle.

Agents and saleyard personnel — checklist

• Where cattle may not be going direct to slaughter, minimise contact between calves and the faeces of cattle that are more than 2 years of age.
• Have pens dedicated to aged cull cows only, preferably pens that are exposed to plenty of sun and which dry out quickly.
• Have pens dedicated to young calves only.
• Avoid walking calves long distances through muddy laneways. This might entail keeping calves in pens closest to the loading ramps, provided they will not be exposed to runoff from the loading ramps.
• Fix any drainage problems in yards so that they stay as dry as possible.
• Hose down hard surfaces as soon as possible after sales, to allow maximum drying time.
• Where hosing is not possible, clean up gross faecal contamination between sales, especially in pens that were holding older animals.
• Know and comply with zoning requirements – see Stock permitted into NSW BJD Protected Zones.

For more information on managing the risk of BJD spreading in saleyards see:

• Supporting BJD zoning — guidelines for agents and saleyard operators;
• Animal Health Australia website.

Truck drivers — checklist

• It is more important to have a clean truck when carting to and from store sales than when carting to and from slaughter sales.
• Know which zone you are operating in! Cleaning your truck thoroughly is more important if you have just carted adult cattle from a Control Zone, especially if they were dairy cattle.
• Minimise contact between calves and the faeces of cattle that are more than 2 years of age, especially if operating in a Control Zone. For example, load calves and yearlings on the top deck of a double-decker, with older cattle loaded below.

Show and sale organisers — checklist

• The site should allow for separation of stock of different status.
• Set-up must prevent the transfer of faeces or faecal contamination between sections holding cattle of different status.
• Calves must be tethered or confined, to prevent them wandering.

For more detail see Cattle Johne’s disease – guidelines for shows, sales and exhibitions.