[twizzel]

Keep your eyes peeled, I’ve just clipped a dry ewe hogg out after finding her struck this evening. Pretty badly struck but managed to catch it early. Just thought I’d give everyone a heads up 

[Fleecewife]

Very timely Twizzel thank you.  With the warm weather flies are likely, although being so dry might work against the flies.  Humid days are the worst.

[twizzel]

We’ve had a very damp week with heavy rain and sunny spells. Perfect for it and heard 3 or 4 other farmers having problems too 

[RCTman]

Yes I had 2 ewes with strike this morning, caught it early, be aware everybody.

[vfr400boy]

What's the best way to prevent strike?

[Donska]

we found some too!  our poor ryeland had been looking a bit off colour - got him sheared yesterday and there was a patch - he'll be fine but it's such a worry!

[landroverroy]

What's the best way to prevent strike?

Presuming you've only got a few sheep, the cheapest product to get is Spot on. It's essentially the same chemical as Crovect but available in smaller quantities. It is also a lot more concentrated than it needs to be and is irritating in this concentration. Try it on your arm if you don't believe me. I dilute it about 5 - 10 times with oil, as it's oil soluble. You can use cheap cooking oil or baby oil (liquid paraffin) or whatever. I find it's more effective to use larger amounts of the diluted Spot on, as you can drench the area affected without over applying it, and it is still 100% effective.
Hopefully vfrboy you haven't actually got flystrike in your sheep and are just asking the question as a precaution. [size=78%]    [/size]

[twizzel]

We use Clik on the lambs and after shearing on the ewes, but our sheep haven’t been shorn yet so it’s just a case of watching them and catching it early. Barrier Blowfly Repel is chemical free and have used that with some success. Shearer coming the week after next providing the weather plays ball 

[SallyintNorth]

What's the best way to prevent strike?

Presuming you've only got a few sheep, the cheapest product to get is Spot on. It's essentially the same chemical as Crovect but available in smaller quantities. It is also a lot more concentrated than it needs to be and is irritating in this concentration. Try it on your arm if you don't believe me. I dilute it about 5 - 10 times with oil, as it's oil soluble. You can use cheap cooking oil or baby oil (liquid paraffin) or whatever. I find it's more effective to use larger amounts of the diluted Spot on, as you can drench the area affected without over applying it, and it is still 100% effective.
Hopefully vfrboy you haven't actually got flystrike in your sheep and are just asking the question as a precaution.

Take care if using Spot On where you would have used Crovect.  Firstly, the meat withdrawal is 8 days for Crovect (cypermethrin 1.25%) and 35 days for Spot On (deltamethrin 1%)

Secondly, the product data sheet for Spot On does not give flystrike prevention as a tested use.  (It can be used to treat an established strike, but says nothing about using it as a preventative for flies in sheep.). I take llr's point that the two chemicals are very similar, but I for one have no knowledge of deltamethrin as a fly strike preventative, (although I can vouch that it keeps flies off cattle.)

Crovect must not be used on animals producing milk for human consumption.  Spot On has a 0 withdrawal for milk in cattle but states not to be used in sheep producing milk for human consumption.

[shep53]

2 different modes of action CROVECT in blowfly protection only protects where the product is sprayed and sits in the wool grease  SPOT -ON in tick /lice mode ( no blowfly protection ) is absorbed in to the skin layers and slowly travels all over the body via blood

[Fleecewife]

2 different modes of action CROVECT in blowfly protection only protects where the product is sprayed and sits in the wool grease  SPOT -ON in tick /lice mode ( no blowfly protection ) is absorbed in to the skin layers and slowly travels all over the body via blood

So think carefully just exactly which chemicals you are happy to have in the meat you eat (if you are going to be the one who eats your sheep)

We have always used Crovect.  We apply it to the lambs, usually in mid May.  The ewes we do after shearing.  There are two reasons for this, one that the shearer really doesn't want to be well bathed in Crovect when s/he's shearing, as he/she will suffer a build-up of the chemical the more animals handled, and two anyone handling the shorn fleece will suffer the same contamination.  Crovect is effective for 6 weeks on the sheep, but remains on the fleece for a good three months, so unless you intend to do the shearing yourself then discard the fleece, do not spray within 3 months up to shearing.
If your sheep are machine shorn then you need to wait a couple of weeks before spraying to give some wool for the stuff to cling onto.  If you are blade shearing there is enough wool residue that you can spray straight away.
So if your sheep are unshorn and there are flies bothering them, shear them straight away.

[PK]

Regarding the point about Crovect only being effective where the product is sprayed - I find keeping to the recommended dose/quantity no where near provides full coverage. And this is with using a Crovect brand spray gun.

[twizzel]

2 different modes of action CROVECT in blowfly protection only protects where the product is sprayed and sits in the wool grease  SPOT -ON in tick /lice mode ( no blowfly protection ) is absorbed in to the skin layers and slowly travels all over the body via blood

So think carefully just exactly which chemicals you are happy to have in the meat you eat (if you are going to be the one who eats your sheep)

We have always used Crovect.  We apply it to the lambs, usually in mid May.  The ewes we do after shearing.  There are two reasons for this, one that the shearer really doesn't want to be well bathed in Crovect when s/he's shearing, as he/she will suffer a build-up of the chemical the more animals handled, and two anyone handling the shorn fleece will suffer the same contamination.  Crovect is effective for 6 weeks on the sheep, but remains on the fleece for a good three months, so unless you intend to do the shearing yourself then discard the fleece, do not spray within 3 months up to shearing.
If your sheep are machine shorn then you need to wait a couple of weeks before spraying to give some wool for the stuff to cling onto.  If you are blade shearing there is enough wool residue that you can spray straight away.
So if your sheep are unshorn and there are flies bothering them, shear them straight away.

If you observe the meat withdrawals there should be no chemicals in the meat?


And also it’s easier said than done to shear straight away- my shearer is tied up until the week after next and also reluctant to shear them if they aren’t ready. 

[landroverroy]

I keep reading on here about not using permethrin type products before shearing, but that is exactly what they are designed for as the greatest risk of flystrike is when the wool is thick before shearing. As Twizzel says - we can't all get our sheep shorn at the same time and so have to use preventative methods.


Fleecewife actually mentions that the shearer "doesn't want to be bathed in Crovect" and that he/she will suffer a build up of the product"  Sorry but that's rubbish. For a start chemicals of this family have been developed from pyrethrum which is a natural plant product evolved specifically to kill insects. Its action is therefore lethal to insects but has not been found to affect mammals to anything like the same extent.  (I'm not saying it doesn't affect them and cats in particular can have a reaction)


So the permethrin family has low toxicity to mammals and I fail to see how the  shearer would get bathed in the stuff as no one is going to shower their animals in it just before the shearer arrives! I would expect it to have dried on the fleece pretty well before then. In addition, only 1%  of that which gets on the skin is absorbed through the skin in humans, and of that 50% is excreted within 24 hours. So the "build up of the product" is another myth.  I also very much doubt if commercial sheep farmers are going to discard their fleeces because they have treated for flystrike. So please lets keep things in perspective and not spread scare tales.
 

[Fleecewife]

2 different modes of action CROVECT in blowfly protection only protects where the product is sprayed and sits in the wool grease  SPOT -ON in tick /lice mode ( no blowfly protection ) is absorbed in to the skin layers and slowly travels all over the body via blood

So think carefully just exactly which chemicals you are happy to have in the meat you eat (if you are going to be the one who eats your sheep)

We have always used Crovect.  We apply it to the lambs, usually in mid May.  The ewes we do after shearing.  There are two reasons for this, one that the shearer really doesn't want to be well bathed in Crovect when s/he's shearing, as he/she will suffer a build-up of the chemical the more animals handled, and two anyone handling the shorn fleece will suffer the same contamination.  Crovect is effective for 6 weeks on the sheep, but remains on the fleece for a good three months, so unless you intend to do the shearing yourself then discard the fleece, do not spray within 3 months up to shearing.
If your sheep are machine shorn then you need to wait a couple of weeks before spraying to give some wool for the stuff to cling onto.  If you are blade shearing there is enough wool residue that you can spray straight away.
So if your sheep are unshorn and there are flies bothering them, shear them straight away.

If you observe the meat withdrawals there should be no chemicals in the meat?

Well that's the multi-million dollar question, isn't it. Presumably, tests have been done to identify at what point levels of chemicals have fallen below an 'acceptable level' in the meat. But what I, or you, or anyone else considers to be acceptable may well differ by a long mile.  I've never used Clik, and even with Crovect I would prefer any sheep going for slaughter, always for our own consumption, not to have any chemical residues at all when we come to eat them.  Of course, I know there are so many chemicals floating around that we are all ingesting some contaminants with our food, whether we produce it according to 'organic' principles or not.
So it's a matter of personal choice, but it's good to be aware of the options.