Why? During late pregnancy a ewe’s immune system becomes weakened, therefore the worm burden that is usually kept subdued can flourish and an increased number of worm eggs can be released onto the pasture. This is referred to as ‘peri-parturient rise’ or spring rise. This increased contamination can threaten the lambs grazed on this pasture throughout the season. Multiple factors can affect when the spring rise will occur, including; lambing date, age of ewes, litter size, nutrition, and condition. Nutrition in the lead up to lambing can be particularly important as protein is essential for the immune system. Faecal egg counts (FECs) are the best way to identify when the spring rise will occur.
The restrictions? The majority of a farm’s worm population are found inside the ewes at lambing time, this means that worming at this point is at risk of selecting for resistance. As only resistant worms will survive, only resistant worm eggs will contaminate the pasture.
The solution? To avoid selecting for resistance:
Do not treat all your ewes.
Select if possible 10% of each group to leave untreated, these ewes should be under the least pressure i.e. older ewes and have a good body condition score.
Do not use the same anthelmintic group year on year
Avoid using long acting wormers (Moxidectin) if turning to low risk fields and late in the spring rise (e.g. post lambing / turnout)
Timing— use FEC to help determine when or if needed.
When to use your FECPAKG2 system?
Start testing either at housing or 3/4 weeks pre lambing (e.g. with clostridial vaccination)
If FEC count is low, test again at lambing (FECs can increase even if they housed). Decide if turnout dose needed.
Test all groups/mobs separately; ewes with multiples / thinner / younger ewes are at more risk of an increased worm burden.
The ewe’s full immunity to worms should return 8 to 10 weeks post lambing. Continue to monitor your ewes up to this point and treat if necessary. Don’t forget to start FECs for your lambs!
Avoid treating more than once during the spring rise if possible.
Getting the timing right is more difficult for outdoor lambing flocks.
Some clients have found only about 40% of ewes needed worming at all and the timing has changed significantly!
Liver fluke, Fasciola hepatica, is a highly pathogenic parasite which causes severe liver damage, especially in sheep, and can result in the sudden death of previously healthy animals. Millions of pounds are lost every year by livestock producers due to liver fluke with the cost of disease per affected animal noted as £6 per lamb and £90 per calf.1
Fluke life cycle
All three stages of liver fluke damage the liver and can cause clinical disease and production losses. The lifecycle of the fluke has a portion outside of the animal and involves a mud snail which thrives in wetter areas.
It is therefore unsurprising after the prolonged above average weather experienced this summer that current guidance from the NADIS August parasite forecast predicts moderate risk in the north and west of Scotland, and low risk in all other regions. However, this doesn’t mean that there will be no, or limited, fl uke across the country in autumn, so it is important to still remain vigilant.
Consider local factors
Control programmes should always take into account the farm history, topography, geographical location and the prevailing weather. Even in years where disease challenge may be lower than normal, vigilance is still important, and special consideration should be placed on fixing any leaky water troughs, fencing off wet or boggy areas in fields and maintaining effective drainage to reduce snail habitats.
For more information please contact your Wynnstay Animal Health
The four elements of sustainable liver fluke control are:
1. Pasture protection – to prevent liver fluke eggs reaching the pasture when snails are active
2. Pasture management – to reduce snail habitats and therefore reduce snail numbers
3. Grazing management – to avoid grazing high risk pastures with susceptible animals at high risk times of year
4. Strategic treatments for at risk animals – controlling the right stage of liver fluke, at the right time, using the right product.
For more information please contact your Wynnstay Animal Health Specialist or SQP in-store.
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