[DartmoorLiz]

I have picked this up as a separate thread from the "worming sheep" thread because I don't want to crash where that thread is going.


We have established that my flock of 50 ewes and 50 lambs need worming.  They have now all had a dose of Zolvax.  They are not now worm free as I have only one aftermath field and the lambs got that, the ewes got the best of the rest and the ram and friends are on a pretty good field sharing with ponies.


Should I cull all the ewes and restock?  If not, how and when do I now go about selecting for worm resilience?

[shep53]

How would you source 50 new ewes that had total resistance to the worms on your grass ??    You can buy rams that have been recorded for low worm egg counts so one of these would start to produce daughters with tolerance .      You  can  take individual dung samples from every female and have FECS done then you will know who is good to start a flock to breed worm tolerance given time

[Backinwellies]

|You will need several generations of selection to achieve what you want ... there is no quick fix. Just cull bloodlines which seem to be susceptible (these ofcourse may be the ones you want to keep cos they are ... good mothers / friendly / good feet etc ... so it isn't that easy) 

[DartmoorLiz]

You are right shep, even if I could source resilient ewes, they may only be resilient to the worms where they come from.  You make the point about purchasing recorded rams; I've read a bit about them but have never found a source.  Am I missing something?


You're right too BIW.  I'm currently focusing on clearing out persistently lame sheep.  If I added in worm susceptibility too I may get to the point that a total clear out is not that big a step. 

[CarolineR]

Hi Liz,

Sorry to butt in to another one of your threads, I just wanted to point out that genetic susceptibility/resistance is only one of the many, many factors that could have resulted in an adult ewe which appears to be wormy.
Time of year (the periparturient egg rise around and just after lambing) comes to a large proportion of ewes regardless of genetics
Pasture - if it is very heavily infested, then no matter what type of sheep you put on it, you may have problems
Deficiencies  of trace elements can sometimes impact on sheep's immune system, making it susceptible due to the grass it is eating - new sheep would develop the same

It may be worth talking to your vet in more detail about how many of your ewes seem to have worms and just how bad it is - is there a few that are just dragging a bulked faecal egg count into the high zone? Are all the ewes individually showing high egg counts? Is there a lack of protein for some reason, such as concurrent fluke?
More detail could help you work out if your ewes are really the problem or if it is the nutrition in the pasture, or your worm burden on the premises, or something else.

Hope that's helpful - if you know how "wormy" they are, and if you know if that is across the board or a few rogue individuals bumping a bulked count up, you will hopefully be able to narrow down possible causes.

Caroline

[Marches Farmer]

If you buy in new sheep you'll have to start from scratch.  You could be buying in Johnes, Jaagsiekte, CODD, orf, Border Disease, etc., etc.  Worm resistance isn't that high on my own list of traits to select for - everything from getting in lamb within 18 days of running with the ram to keeping condition through lactation are higher.   Is it possible for you to split a field to give cleaner grazing for lamb turnout?

[Big Light]

Sow some anthelmic plants would help also

[Anke]

If the majority of your ewes have high worm egg counts than I would think you have only one solution to reduce the worm burden on your land - drastically reduce the number of ewes, in order to keep at least one field (half your acreage?) rested for 12 months (and graze it with cattle in the meantime, or just use for hay, or both) and then once that field is clear use something like Zolvix to get them as worm -free as possible and then move to that clean grazing, and move fields round to get others rested afterwards, similar procedure.... and operate a closed flock afterwards. Lower stocking density will also help in the long-term...

I would also investigate the trace element deficiency angle as mentioned above, and probably cull the worst offenders.

[shep53]

For starters  TIM W and  INNOVIS  certainly  do individual FEC and record rams ,  PETER BABER   ,     EASYRAMS

[shotblastuk]

Are certain breeds/crosses more susceptible to worms than others?

[Tim W]

Are certain breeds/crosses more susceptible to worms than others?

No ---many breeds claim to be great at many things and if you believed the blurb they churn out you would have a flock of sheep that raised twins to 40kg in 8 weeks on docks and thistles only 

In my experience there are individuals in every population that are good at worm resistance ---it's just a case of identifying these animals and breeding from them , repeat for a few generations and you get a population that on average is more resistant to worms
Our ewes in the top 25% for FEC now only excrete 50% of the eggs that the ewes in the bottom 25% (measured over the first 8 weeks of lactation -periparturent rise )---but this kind of progress requires selection over a few generations in a large population = lots of individual FEC & a decent BLUP analysis

[Tim W]

Hi Liz,

.
Time of year (the periparturient egg rise around and just after lambing) comes to a large proportion of ewes regardless of genetics

Pasture - if it is very heavily infested, then no matter what type of sheep you put on it, you may have problems
Caroline

Egg output in periparturient rise varies between ewes and is heavily controlled by genetics, I know because we measure this

resistant ewes will by definition hoover up worm eggs from the pasture---very resistant ewes can be used to clean pasture although this will never be 100% successful (and we don't really want it to be) 

[Cuddles]

resistant ewes will by definition hoover up worm eggs from the pasture---very resistant ewes can be used to clean pasture although this will never be 100% successful (and we don't really want it to be) 

Hi Tim, this is probably a silly question but is it known how the resistance works?  i.e what is happening to the adult worms inside the sheep?  Are they being destroyed or is something simply inhibiting the worms reproductive cycles?

[DartmoorLiz]

Wow, so much to think about: 
Caroline: I hadn't thought of concurrent fluke.  Is it too early to treat?  Blood test shows trace elements are OK.
Anke: Our numbers are already reduced - when the farm was in full swing they had 80 ewes - and cows, goats and pigs - there was more muck and child labour in those days.  [/size]I have great plans to split the big field ... meanwhile ... . 
[/size]Shep: Thanks for the pointers, I'll contact them direct. Hopefully they do lleyn or blackface rams.
Tim: [/size]Back in 2012 I was a bit of a sucker to the blurb when I bought some lleyns that had not read their web site. [/size][size=78%]I have been using the ewes to hoover up after the lambs since weaning while waiting for the aftermath to grow so the ewes have been under some pressure.  Not so much the cream rising to the top as sinking in the mud.  [/size][/size][size=78%]  [/size]
Big Light: any suggestions on antihelmithic plants?   
Marches: [/size]Its nice to think that there could be someone out there with a worse flock than mine (its that time of year when it all becomes a bit depressing so counting my blessings is really helping).  [/size]I'll work with the flock I've got, cull the poorest and give the best gold stars. 
[/size]Thanks everyone

[Tim W]

resistant ewes will by definition hoover up worm eggs from the pasture---very resistant ewes can be used to clean pasture although this will never be 100% successful (and we don't really want it to be) 

Hi Tim, this is probably a silly question but is it known how the resistance works?  i.e what is happening to the adult worms inside the sheep?  Are they being destroyed or is something simply inhibiting the worms reproductive cycles?

From what I understand it's an immune response to the parasite infection----and worm eggs are destroyed in the gut . I could probably post links to some of the work but it gets a bit too deep for me (too many long words to follow)