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You are here: Agriculture » Pests, Diseases and Weeds » Animal Diseases » Beef and Dairy Cows » Bovine Johnes Disease » BJD and Purchasing Cattle

Purchasing Dairy Cattle and Minimising the Risk of Buying Bovine Johnes Disease

Note Number: AG1203
Published: December 2005
Updated: July 2009

 

This agriculture note discusses some of the issues that herd owners should consider when purchasing dairy cattle so that they can minimise the risk of also buying bovine Johnes disease (BJD).

When purchasing cattle, buyers should consider both the effect that the purchase may have on the BJD status of their herd AND the risk of introducing BJD into their herd. These are very separate issues.

Information to consider prior to purchase

Before purchasing breeding cattle it is important to consider

• the current BJD status of the vendors herd
• the current BJD status of your herd
• the calf rearing practices on the vendors property
• the number of cattle being purchased
• experience from previous purchases from the same source
• the impact that introducing animals might have on the BJD status of your herd
• the risk that animals from that herd could introduce disease into your herd
• the calf rearing practices on the purchasers property
• the long-term management plans for your herd

Purchasers should request a National Dairy BJD Assurance Score declaration with every consignment of cattle purchased. This is a formal, written method of providing much of the information a purchaser needs to make an informed decision about buying dairy cattle.

National Dairy BJD Assurance Score

The National Dairy BJD Assurance Score is a national dairy industry initiative that provides a simple method of scoring ALL dairy herds in relation to their likelihood of having, or spreading, BJD. Herds have a score of 0 to 10 depending on where the herd is in Australia, the history of BJD, the history and outcomes of testing for BJD, and the calf rearing practices in the herd. The higher the score the better the assurance the cattle do not have BJD.

This means it is a simple way of allowing purchasers of dairy cattle to compare the risk of BJD in a group of cattle being offered for sale with other sale lots, and against the score of their own herd.

If you are purchasing herd replacements you should buy cattle that have a dairy BJD score that is the same or greater than the basic score for your own herd.

For further information on this subject contact Dairy Australia, Animal Health Australia  or see the Agriculture Note The Dairy BJD Assurance Score, for more information on this subject.

CattleMAP herds

CattleMAP herds are the source of replacement cattle that poses the lowest risk of introducing BJD into the recipient herd.

Enhanced trading options

In Victoria, cattle raised under the Johnes disease calf accreditation program (JDCAP) from Tested Low Prevalence (TLP), Restricted (RD) or Suspect (SU) dairy herds have a low risk of being infected with the BJD. In recognition of this, TLP, RD and SU dairy herds now have the opportunity to sell JDCAP reared cattle to most dairy cattle herds in Victoria with no change in BJD status being made to the recipient herd.

See the Agriculture Note Enhanced trading options for dairy herds in the Victorian Johnes disease control program, for more information on this subject.

Non-Assessed herds

Many Non-Assessed (NA) dairy herds in Victoria are likely to be infected with BJD. If the calf rearing procedures of JDCAP are not practiced, cattle from these herds, while not directly affecting the official BJD status of the recipient herd, can pose a high risk of introducing BJD into the receiving herd.

Other considerations

Repeat purchases from the same source over several years (eg bulls from the same stud) can provide the purchaser with some confidence about buying again from the same herd.

In other cases, purchasers may need to discuss the situation with their private veterinary practitioner or DPI animal health staff, or they may need to visit the vendors property to view the calf rearing arrangements and the Dairy BJD Assurance Score documentation for themselves.

Please remember that DPI staff cannot disclose confidential information about another persons herd or property without that persons written approval.

More information

Further information about BJD can be obtained from Animal Health staff at your nearest DPI office, or on the DPI external website:

Acknowledgements

This Agnote was developed by Sally Ridge, December 2005.

It was reviewed by Ian Mclaren, Biosecurity Victoria. July 2009.