Keep diseases out
Jeff Cave, Senior Veterinary Officer, Northern Region
Consider the time and money that you have spent keeping your flock healthy and add up the investment that you have made. Now think about the steps that you might take to prevent the introduction of disease.
Truly closed flocks are uncommon. When you moved livestock what actions did you take to reduce the risk of introducing an infectious disease into your flock?
Purchasing sheep that have the least disease risk must be a primary aim of farmers when buying sheep. Diseases such as footrot can seriously disrupt the enterprise.
The risk of the introduction of disease can be minimised by getting a good history of the livestock to be introduced. Did the vendor breed them? Is the vendor’s herd closed? Has the vendor provided a declaration relating to the disease status of the properties on which the livestock have been kept? Are the livestock derived from a tested or accredited herd? What is their drenching and vaccination history?
Introduced sheep should routinely be isolated from other sheep until they are determined to be free from diseases or pests. Drenching sheep on arrival with an effective chemical and moving them to an isolation area will limit the risk of introducing drench resistant worms. During the quarantine period the newly introduced livestock should be examined for disease and external parasites.
Footrot can remain undetected in the feet of sheep for long periods, especially during dry conditions. Ideally, introduced sheep should be kept isolated until they have passed through a suitable footrot expression period, such as a wet spring or autumn.
Similarly, the first signs of sheep lice may not become apparent for 6 months or more from the time of arrival on your premises, and Ovine johne’s disease (OJD) may take years before the first signs of ill thrift and deaths are seen.
Aside from arriving on the back of a truck, the other way in which sheep may arrive on a property is by straying. Are your fences in sufficient order to prevent the introduction of stray livestock from neighbouring properties?
The entry of people, vehicles and agricultural equipment also carries a risk of disease and weed seed introduction. A strategically placed notice, such as on the entry gate of the farm will help to ensure that all visitors check in at the house or office before having contact with stock.
Disinfecting footwear and wearing clean outer clothing should become routine practice for personnel arriving for work on the farm. These measures are particularly critical if workers have been on other farming enterprises and have had contact with other stock.
For visitors to the farm whose primary purpose is a social visit to the family home, disinfection procedures should not be necessary. If visitors need to have contact with stock, biosecurity measures can be imposed.
Vehicles and machinery coming onto the farm should be cleaned prior to arrival. Vehicles not required for specific operations on the farm should be left at the residence and travel undertaken in the farm vehicles.
Prevention is cheaper and easier than cure. A way of ensuring an effective and consistent approach is to document and follow a farm biosecurity plan which promotes good hygiene practices and controls the movement of livestock, people, and equipment onto your property.
Understand the signs of disease. At first suspicion of sickness or a disease that concerns you, contact your local vet or notify Agriculture Victoria on the Emergency Animal Disease Watch Hotline number 1800 675 888.