Best practice on winter sheep dipping – keep water quality in mind
Many sheep farmers will be considering winter dipping in the weeks ahead. Shaun Roarty, ASSAP Advisor, Ballybofey, Co. Donegal, writes on the importance of following best practice and the potential hazards to water quality if not followed.
The benefits of dipping for preventing and controlling ectoparasites, such as lice, keds, ticks and scab, are well known. However, what sometimes is forgotten or unknown is that these insect parasites, which are treated by dipping, are closely related in genetic makeup to the aquatic insects found in our waterbodies.
Therefore, when unintentional sheep dip products end up in a waterbody, it has detrimental effects on the biological functioning of the aquatic insect species present and effectively wipes out their communities.
Aquatic species serve many functions in our waterbodies around the country. They are an integral part of the food chain for fish and the wider aquatic food web.
Our waterbodies serve so many functions for our communities such as ecosystem health, recreational pursuits, providing drinking water and so on.
Sheep dip active ingredients, such as Cypermethrin, are very often detected in minute quantities in waterbodies particularly in hill and mountainous areas around the country where sheep numbers are high.
These detections are very often associated with a toxic impact which is reflected by virtually no beneficial insect species being found in these waterbodies, which has wider ecological implications for all aquatic dependent life.
Minimise any potential hazard to water quality
Therefore, it is extremely important to consider the following when going about sheep dipping on your farm to minimise any potential hazard to water quality and the life it supports:
- Make sure you choose a cool, dry day, with relatively good drying conditions.
- Identify your holding field/paddock for your sheep after dipping, there should be no open drain or watercourse within or adjacent to this area.
- Check that your dipping tank is sound and leak proof, with no structural cracks or defects and has no outlet pipe or valve at the base of the tank.
- Take your time when dipping. Sheep should be allowed to stand for 10-15 minutes in the adjoining drip pen standing area (concreted) when they emerge from the dipping tank to allow dripping solution funnel back to the tank.
- Sheep should be kept in the holding field/paddock for at least 24 hours to make sure that they dry effectively, and to prevent any chance of any sheep accessing or crossing watercourses which could potentially cause dipping product ending up in a drain or watercourse.
- After dipping – wash and brush the dung from the adjoining drip pen stand thoroughly to ensure that no debris including wool enters any drain or waterbody. The brush used should be soaked in water a number of times and rinsed well.
- Empty dip containers and opening caps/foil should be safely disposed of after use, following the manufacturer’s instructions on the data sheet.
- Spent sheep dip should be mixed 1:3 parts either with slurry or water and land spread by a tanker at a rate not exceeding 5,000 litres/ha (440 gallons per acre) of spent dip, equivalent to 20,000 litres/ha (1760 gallons per acre) of diluted dip [1]. Do not spread diluted spent dip outside the closed spreading period and do not spread on wet or waterlogged ground.
- In no circumstances should spent dip be disposed of if there is no facility or slurry tanker available to hold or spread the dip safely. In hill areas, some farmers may not have access to a slurry tank on the farm, however, sheep dip must be disposed of to a tank for dilution and spreading.
- These recommendations also relate to pour-ons which use active ingredients such as cypermethrin. Pour-ons when sprayed on fleece should be allowed to dry effectively before allowing sheep go back to open hill or mountainous areas or any lowland areas where watercourses are present. As with dipping, sheep should be kept in the holding field/paddock for at least 24 hours to dry effectively before return to hill or lowland areas containing watercourses.
- Injectable products to control ectoparasites should be considered where dipping is not feasible. Please check and consult with your local veterinary practitioner for advice.
- The same principles above apply when using mobile showers/dipping.
- Please read manufacturer’s instructions on the data sheet carefully regarding health and safety procedures when using dipping products.
- Unwanted dip products must be disposed of to a licensed specialist waste disposal contractor. Contact your local authority for more information on licensed contractors.