9 April 1999


More sheep producers are

expected to use a

contractor to spray dip their

flocks this season as a way

of reducing the amount of

dip they have to dispose of

under new regulations.

Jeremy Hunt reports

ALTHOUGH spray dipping is not approved for sheep scab, more producers are expected to take advantage of this fast and low-cost method of anti-parasitic treatment, particularly those switching to injectables for scab control.

Lancs farmer Robin Dean, who set up a sheep contracting business last year, is already dealing with inquires from flock owners who want to use spray dipping in conjunction with injectables this season.

"A typical inquiry is from a hill farmer with 2500 Swaledale ewes and very little level land on his farm that would be suitable to take spent dip under the new regulations," says Mr Dean.

"The injectable hes decided to use for scab control does not provide protection against lice so hes going to incorporate a summer spray dip."

Last year Mr Dean, who is based at Keyfold Farm, Broughton, Preston, bought an Electrodip, a spray dipper developed in New Zealand with a capacity to treat 2000 ewes an hour.

The system is based on spraying dip at high pressure onto ewes in a race. An electronic eye, strategically situated in the race, triggers the dip to be sprayed onto ewes from three nozzles above and two nozzles below ensuring effective treatment of the entire animal.

The nozzles on the top are positioned to direct the jet of dip just between the ears and the back of the sheeps head. As each sheep passes through the race, jets spray dip along the animals back while the two lower nozzles apply dip to its underparts.

As the animal leaves the spray area the jets from all five nozzles meet on the hindquarters. Another electronic eye shuts off the jet spray as the sheep leaves.

In practice the spraying appears to be continuous as sheep can be run quickly through the race and still be effectively treated with exactly the right amount of dip. A mid-summer treatment for ewes shorn four weeks previously would require the spray to be delivered at 70-80psi.

"The intention is not to soak the sheep but to enable the jet-spray to penetrate the fleece through to the skin.

"Should the dip run out there is a gate at the front of the race which automatically closes to halt the throughput of sheep until the dip tank can be re-filled," says Mr Dean.

The system does not require ewes to stop at the point of the sprays.

The mobile pump, motor and regulator and the straightforward setting up of the race enables the system to be quickly assembled in field corners as well as yards in about 15 minutes.

A collection tray, positioned immediately after the spray section of the race, captures any surplus dip that may splash from the jets.

Fast, but effective

"Ewes can go through as fast as you like and will still be effectively treated. This is not a substitute for total immersion dipping but it provides a fast and efficient treatment for head fly or lice infestation.

"Compared with pour-ons its so much faster, cheaper and easier. Spray dipping ewes is about half the cost of using a pour-on," says Mr Dean

A mobile tank is provided in which to mix dip on site based on 0.75-1 litre of mixed dip a sheep.

"If 500 ewes are gathered and ready we can put them through in 30 minutes. Once ewes are running the treatment is as fast as they will go through. There is virtually no surplus dip falling off the sheep; we are working on 5-10% run-off so on 500 ewes thats only 30 litres."

All dip that is collected in the tray and any surplus dip left over is taken off the farm and disposed off by Mr Dean if farmer customers do not have a disposal licence.

"We are talking about very small quantities; even if we did two farms in a day its only 10-20 litres of waste dip to dispose of," says Mr Dean.

Ideally sheep should have a bit of wool cover – about three weeks after shearing is the minimum. "But the system is effective with ewes in full wool and there are already inquiries from producers considering treating horned ewe hoggs against ticks.

New Zealand

"Heavier wool cover requires a simple increase in the nozzle pressure. Spray dipping is widely used in New Zealand to treat heavily woolled Merinos and Romneys so British breeds present no problem."

Last year, as an example of the systems flexibility, Mr Dean treated 1000 ewes and lambs for fly strike in one day. They belonged to one farmer and were at five different sites throughout Lancashire.

"The farmers alternative was either to bring the entire flock home where he had a mobile dipper or to take the dipper to every location which was not feasible. We were able to set the spray dipper up in a field corner at each site."

Mr Dean is charging £50 for the first 100 ewes and then 30p a sheep after that. If there are more than 1000 ewes to treat the cost is 30p a head.

&#8226 Complements some injectables.

&#8226 Penetrates fleece.

&#8226 Low quantity of dip required.


BRIAN Parkinson reckons spray dipping was just as good as using an immersion dip when he used the system for the first time last summer to cope with fly strike.

"It took less than an hour from setting up to leaving the field," says Mr Parkinson who runs his Texel-cross flock at Liscoe Farm, Out Rawcliffe, Preston, Lancs.

When he first approached Mr Dean to inquire about spray dipping he admits he was sceptical. "We had previously used a pour-on or a mobile dipper for this mid-summer fly-strike treatment.

"At first I thought it would be difficult to get enough dip on the sheep as they ran through the race but the way the high pressure jets are angled ensures every sheep is thoroughly treated."

Mr Parkinson has been using an injectable scab treatment for the last two years and plans to incorporate a summer spray dip in the future.

"Its the fastest and most efficient way of treating sheep for fly-strike and we were able to set the system up in the field. With all the new rules covering dip disposal I can see a lot more sheep producers turning to injecting for scab and turning to the convenience of a summer spray dip as they need it." &#42

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