[farmerfred]

Hi all, end of March I'm lambing outdoors, I usually lamb indoors and worm then turn out onto fresh grazing however this year as I'm lambing outdoors  shall I worm each ewe as they lamb and immediately move them one by one, or just do the whole group once lambing finished and move.

[winkhound]

1st you have to ask what for and why you're worming them

[bj_cardiff]

I would worm them individually as they lamb and turn the ewe and lambs onto a 'clean(er)' field. I assume you catch newborn lambs and band/mark them - if so shouldn't be too hard to move them at the same time.

I suppose if you are confident they will all lamb within 3 weeks it might be easier to do the lot together? My lambings have always been fairly spread out

[Tim W]

I lamb outside in April----1000 ewes for 25+ years and have never routinely wormed adults

https://www.scops.org.uk/

More than likely a waste of time and only contributing to anthelmintic resistance

[Rosemary]

Our vets advice is to worm adults at lambing when resistance is low and lots of worm eggs are produced, contaminating the pasture for the lambs, which have no resistance (unlike adult sheep).

[Tim W]

Our vets advice is to worm adults at lambing when resistance is low and lots of worm eggs are produced, contaminating the pasture for the lambs, which have no resistance (unlike adult sheep).

Your vet may be a bit behind the times ----present industry recommendations are to dose adults only if needed and to restrict to triplet bearing (twins if they are thin) and other ''at risk'' groups

Periparturient rise in FEC can stretch from shortly before lambing to 6/8 weeks afterwards which is of course longer than most anthelmintics are effective for ---
Best long term method is to breed for parasite resistance
Best short term method is to make sure sheep are in good condition and have low stress levels (plenty of grass etc)

[Womble]

That's interesting [member=29066]Tim W[/member] , and is not what our vet told us either.

Do you have links to any papers etc for further research?  Cheers! 

(BTW, because our ewes are tame and hence not stressed out by being caught or drenched, we worm them a couple of weeks before they lamb if lambing outside. This is the only routine worming we do except for using a white wormer for lambs to control nematodirus.)

[SallyintNorth]

Good post, TimW, but I’d add using rotational grazing.  We do ponies follow sheep follow cattle throughout the year, and some of our new families (ewes and lambs) go onto the areas that pigs will graze later in the year too.

I didn’t worm any ewes or lambs until September this year, when I wormed three of the ewes at weaning as I thought they should have had more condition on them than they did.  (Although they had each reared bigger or more lambs than previously, so perhaps it was just that.). And just one lamb needed worming, in October after biblical rain.  (Could have been the wet grass making it squitty, but none of the others were dirty so I dagged and wormed the one that was.)

It will be interesting to see if the retained ewe lambs need worming next year.  (I didn’t keep the one that had got mucky, I am aiming to breed sheep that don’t generally need interventions, when managed appropriately.)

[Tim W]

That's interesting [member=29066]Tim W[/member] , and is not what our vet told us either.

Do you have links to any papers etc for further research?  Cheers! 

(BTW, because our ewes are tame and hence not stressed out by being caught or drenched, we worm them a couple of weeks before they lamb if lambing outside. This is the only routine worming we do except for using a white wormer for lambs to control nematodirus.)

Links?

Worming at risk groups ? ---See SCOPS

Breeding for worm resistance? ---see https://www.sciencedirect.com/science/article/pii/S0020751919302152?utm_campaign=STMJ_75273_AUTH_SERV_PPUB&utm_medium=email&utm_dgroup=Email1Publishing&utm_acid=-798773639&SIS_ID=-1&dgcid=STMJ_75273_AUTH_SERV_PPUB&CMX_ID=&utm_in=DM611894&utm_source=AC_30
Although the work is a few years old and we have moved on a bit now

When we take mob FEC samples of ewes or lambs and compare Exlana (selected for worm resistance) vs Charollais types ( not selected) we get large differences ---Char lambs may be 650 EPG vs Exlana at 120EPG , similarly with ewes (all animals in same field/same regime etc)

Selecting for worm resistance is not difficult just slow and tedious ---to start a significant statistical analysis you need a minimum of 2000 individual samples over 3 generations , then select and keep building the data base

[Womble]

OK, this is a bit long, but it's also really interesting info (link here):

6.5.2 Dosing of ewes at turn-out For most of the season, healthy adult ewes have high levels of acquired immunity. However, during the period of the peri-parturient relaxation of immunity (PPRI), their immunity wanes and FECs rise. (Section 3). Treatment at this time may have less serious consequences for the development of AR, but the timing of dosing and the choice of anthelmintic are both important. If ewes are still 37 experiencing the PPRI when the effect of anthelmintic dosing ceases, they are likely to become reinfected quickly, particularly if pastures are reasonably infective. Under these conditions, selection for AR is minimal, but the benefit of treatment in terms of pasture contamination (Fig. 2.2) is also minimal.


Ewes that are treated early in the period of the PPRI show only a short duration of reduced egg output before resuming the expected, but delayed, peri-parturient rise in FEC. In the past, repeated treatments have been advised in order to eliminate the rise in FEC altogether (Fig. 6.5). This strategy will reduce pasture infectivity for the lambs later in the season, but will also ensure that the end of the PPRI coincides with anthelmintic treatment, and there may be a prolonged period before ewes re-establish a nematode infection from the in refugia population. This is highly selective for AR worms. Fig. 6.5 Faecal egg counts of ewes grazing infective pastures after turn-out The strategy adopted is therefore a compromise between reduction in pasture contamination for lambs and avoiding high selection pressure for AR.


Two possible options are available:


Leave a proportion of the ewes untreated, to populate the paddock with eggs from unselected parasites (Section 6.7, part-flock treatment, targeted selective treatments (TSTs), or….


Treat early in the post-lambing phase to ensure that ewes become re-infected before their immunity is fully restored.


Both of these approaches increase the risk of parasitic disease for lambs grazing the pastures later in the season. This is clearly an area where careful planning is necessary to develop strategies that give acceptable levels of worm control without undue selection for AR. This is particularly true when using long acting formulations of MOX that provide persistent action and long periods of protection against some species of nematodes for up to several months. Wherever possible these products should be used prior to lambing or early in the PPRI.

 
I understand that to mean that our strategy of worming pregnant ewes 2 weeks before lambing is acceptable, particularly given that we don't worm gimmers or tups at that point, and they're immediately put back onto infected pasture. What I'll do I think is to not worm any older ewes scanned with singles, since they'll be under less stress. I'm not too sure what else to change though - this is a really complicated topic!


What is interesting is that we have nematodirus here which, whilst still killed by group 1 white wormers, are resistant to a group 3 clear wormer. This is despite never having used group 3 wormers until last year. I'm not aware of any other resistance though.... yet! 

[Rosemary]

Your vet may be a bit behind the times ----

I'll tell him you said so.

[SallyintNorth]

That's interesting [member=29066]Tim W[/member] , and is not what our vet told us either.

One thing it took me a while to realise is that the advice changes, sometimes on a yearly basis, especially about worming.  So we will gaily go along, doing what the vet advised us when we started, not realising that the vet is now on the xteenth revision of that advice for people starting now... :/

We did a couple of years on schemes where we got a lot of vet time and attention, so I had some wonderful in-depth convos with our vet.  One thing he said at one point was that it can be beneficial to give the lambs limited exposure to worms so that they develop some resistance.  But you have to be careful of course, you haven’t got time to let them develop resistance to cocci, for instance, so if you have that on your land you must be preemptive.

[SallyintNorth]

Selecting for worm resistance is not difficult just slow and tedious ---to start a significant statistical analysis you need a minimum of 2000 individual samples over 3 generations , then select and keep building the data base

On your scale, yes.  On our scale - less than 20 ewes - I just keep records of who needed worming and de-select ewes and lines that needed worming when I didn’t think it was justifiable.  Oh, and have a significant proportion of Shetland and Manx blood in the flock  

[Tim W]

Advice does change rapidly as we understand more about worms/genetics/anthelmintics etc

One thing i have learnt is that no breed is more resistant to worms than another ---regardless of the claims many societies make
Some individuals within a breed will have superior resistance of course and some recorded /selected populations will be better but heretabilites are low and the selection process is long
One flock i have FEC'd had Shetland x ewes and mules all running together ---there was no difference in mob counts

I do plenty of FECs for plenty of farms and get to compare breeds against each other ---in general the terminal sires have been bred for growth & carcase and little else and so have poorer worm resistance compared with maternal breeds

[SallyintNorth]

Hmm... how are you measuring resistance?  Maybe I am in fact selecting for tolerance, sheep which can tolerate a moderate worm burden and show no symptoms.