Cydectin la on ewes prior to lambing

[Jmorrow]

Last year I had a scab outbreak due to neighbours store lambs.
So we decided to use cydectin as dipping ewes prior to lambing would have been tough on them. We used cydectin la 2 weeks before lambing on whole flock.
We also wanted to worm the ewes due to the ewes being in poor condition prior to lambing due to nutrional demands as silage was particularly poor dm. So we thought this killed two birds with one stone type idea.
I found out after this that moxedictin resistance was on the rise due to people using it annually on ewes prior or post lambing. (Due to small amount the drug being passed passively through the mothers milk leading to anthelmintic resistance.)
So therefore I am hesitant on using it again.
Although We found that we didn't have to worm any lambs until they were 9 weeks old apart from a small batch of problems that had a bad hit with nematodirus (All groups of lambs are FEC every 2 to 3 weeks). So only one batch of lambs were wormed with a white wormer before 9 weeks compared to every batch having a white wormer for nematodirus and a clear wormer the year before in the same time period. Altogether on average the lambs were wormed 3 times less than the year before with the only changing factor the cydectin. Lambs were 3kg heavier than year before at 90 days also although this was also due to a problem with coccidiosis the year before.
My thought is that the ewes that recieved cydectin acted as hoover after lambing, hoovering up all the worms therefore reducing the overal worm burden on the lambs.
Then I though that I could reduce the number ewes receiving cydectin this year for example a third (triplet bearing ewes and (doubles/single in poor condition) in each batch therefore reducing the overal animal exposure to moxidectin but also gaining the hoovering affect from a third of the ewes therefore reducing the overal worm burden and reducing the overal amount of wormers used on the lambs on the farm.
My question is would this still lead too resistance to moxedictin?
And does anyone else use moxidectin as a hoover like this?

 

[neilo]

Last year I had a scab outbreak due to neighbours store lambs.
So we decided to use cydectin as dipping ewes prior to lambing would have been tough on them. We used cydectin la 2 weeks before lambing on whole flock.
We also wanted to worm the ewes due to the ewes being in poor condition prior to lambing due to nutrional demands as silage was particularly poor dm. So we thought this killed two birds with one stone type idea.
I found out after this that moxedictin resistance was on the rise due to people using it annually on ewes prior or post lambing. (Due to small amount the drug being passed passively through the mothers milk leading to anthelmintic resistance.)
So therefore I am hesitant on using it again.
Although We found that we didn't have to worm any lambs until they were 9 weeks old apart from a small batch of problems that had a bad hit with nematodirus (All groups of lambs are FEC every 2 to 3 weeks). So only one batch of lambs were wormed with a white wormer before 9 weeks compared to every batch having a white wormer for nematodirus and a clear wormer the year before in the same time period. Altogether on average the lambs were wormed 3 times less than the year before with the only changing factor the cydectin. Lambs were 3kg heavier than year before at 90 days also although this was also due to a problem with coccidiosis the year before.
My thought is that the ewes that recieved cydectin acted as hoover after lambing, hoovering up all the worms therefore reducing the overal worm burden on the lambs.
Then I though that I could reduce the number ewes receiving cydectin this year for example a third (triplet bearing ewes and (doubles/single in poor condition) in each batch therefore reducing the overal animal exposure to moxidectin but also gaining the hoovering affect from a third of the ewes therefore reducing the overal worm burden and reducing the overal amount of wormers used on the lambs on the farm.
My question is would this still lead too resistance to moxedictin?
And does anyone else use moxidectin as a hoover like this?

No ai is passed through the milk to the lambs, that is not the reason the use of Cydectin LA leads to a rise in resistance. The problem is that the amount of wormer in the ewe’s system wains gradually over many months, so any ingested worms are getting a sub-lethal dose after a while. That is what causes resistance, just the same as regularly under-dosing sheep does.

However, the use of Cydectin LA does indeed work fantastically to hoover up worms on pasture, reducing the need to worm lambs, as you observed. That’s the case, right up to the point where it doesn’t work any more, and you can no longer use that entire (clear) wormer group effectively on your farm, probably ever.

Do you want a quick fix at the expense of a (very) long term problem?

 

[Jmorrow]

Found this document on scops which I found interesting.
Explains most of the problems although I would argue using cydectin responsibly on few ewes would reduce the overal wormers that I use.
I also hope genetics will pay its part in the long-term future of my flock I have already seen an improvement in my lleyn and new Zealand Suffolk groups in wom resistance compared to my old type of ewe char/tex/suff.

 

[tepapa]

Found this document on scops which I found interesting.
Explains most of the problems although I would argue using cydectin responsibly on few ewes would reduce the overal wormers that I use.
I also hope genetics will pay its part in the long-term future of my flock I have already seen an improvement in my lleyn and new Zealand Suffolk groups in wom resistance compared to my old type of ewe char/tex/suff.

You are right, it would reduce the over all amount of wormers you use. Remembering moxidectin is the easiest drug to get resistance to, so in a few years it won't work at all, and along with resistance to white, and your probably resistance to yellow you'll only be left with the expensive newer orange and purple groups. So you won't have much choice.

 

[neilo]

Found this document on scops which I found interesting.
Explains most of the problems although I would argue using cydectin responsibly on few ewes would reduce the overal wormers that I use.
I also hope genetics will pay its part in the long-term future of my flock I have already seen an improvement in my lleyn and new Zealand Suffolk groups in wom resistance compared to my old type of ewe char/tex/suff.

That is interesting, and I hadn’t seen it before. I see that as a big pharmaceutical company going on the defensive against an industry body that has been actively advising against their product. Nothing unusual in the conclusions though.

 

[Jmorrow]

I think Ill use up what cydectin I have left this years on the triplets and ewe lamb double/triplets and move
to not worming any adult sheep in the near future.
Would you still worm ewe lambs pre lambing?
With a clear drench?