Network surveillance of M. bovis
Network surveillance aims to control the spread of M. bovis by using tracing tools to follow-up properties linked to the network of Confirmed Properties. All cattle movements onto and off confirmed properties are identified through tracing. Any properties which could be the source of infection or could have received infected cattle are investigated.
Properties in proximity to a Confirmed Property or operated by the same owner/enterprise (owner other) are also determined to be at risk. A risk event is created against a property when it is determined that there is an increased risk of M. bovis infection on that property. Risk events require further investigation and may lead to on-farm sampling with or without movement controls.
Cattle on a property determined to be at low risk of infection are sampled under Active Surveillance (no movement controls). Cattle on a property determined to be at high risk are sampled under a movement control Notice of Direction (NOD). This balanced approach means we stop the risk of spread from those properties assessed to be higher risk of infection while not impacting the business of those properties which are considered lower risk.
Background surveillance includes the bulk tank milk screening and the beef and drystock cattle surveillance. As we progress towards eradication, we also accumulate data supporting an absence of M. bovis infection across New Zealand.
Bulk tank milk screening
Bulk tank milk screening is a tool used to test each commercial milk supplier. This allows us to identify infected properties faster than we could by tracing cattle movements alone.
If a bulk tank milk sample is reported with a “detect” result, this means that there is an indication that an immune reaction may be present. This is not a confirmation of infection.
To resolve a detect result, we need to carry out further on-farm sampling to determine the true infection status of the milking herd.
Beef and drystock cattle surveillance
Beef and drystock cattle surveillance covers a range of farming systems including commercial terminal beef herds, beef breeding herds, dairy heifer grazing properties, and small and non-commercial farming enterprises.
Cattle are blood sampled during routine farm management procedures, at meat processing plants, and at a feed lot.
So far to July 2022, the findings indicate that M. bovis is not widespread in beef and drystock properties outside the network of Confirmed Properties.
Who to contact
If you have questions:
- phone MPI on 0800 00 83 33
- email firstname.lastname@example.org