Weekly Blog
Gut worms in beef youngstock – treatment and tips to reduce the development of resistance
Gut worms in beef youngstock – treatment and tips to reduce the development of resistance
- Worming beef youngstock
- Treatment options
- How to administer wormers correctly
- Other treatments that may be required
- Minimising worm burdens in beef youngstock
Historically, gut worms in cattle have been controlled with regular, routine worming treatments, without always thinking about whether wormer treatments were necessary. We know from the sheep industry that unnecessary worm treatments contribute to the build-up of wormer resistance which has significantly limited the wormer classes available to some farms. The issue of wormer resistance has not been as well documented in cattle- we need to be thinking ahead and aiming to control gut worms in beef cattlein a targeted way to delay the build-up of resistance in the worm population. The range of wormer drugs licensed for cattle is much more limited than for sheep, meaning we need to use the drugs we have responsibly whilst effectively controlling disease.
If you want to know more about which gutworms affect beef youngstock please read our other blog – ‘Gut worms in beef youngstock –which worms are a problem and how to diagnose them’.
Worming beef youngstock while at grass
‘Preventative’ Treatment systems have commonly been used where pastures are consistently grazed, not rotated. It aims to treat at the beginning of the grazing season, within the 1st 3 weeks of turnout, to reduce the number of worm eggs shed onto the pasture. Products used are often long-acting– such as injectable ML’s. This approach requires less handling and diagnostic testing but can select heavily for anthelmintic resistant (AR) worms, an increasing problem in UK sheep flocks and starting to be diagnosed in cattle farms.1This approach can also lead to ‘overworming’, causing a lack of immunity to both gut worms and lungworm.
It is rare for healthy cattle aged over two years old to require any treatment for gut worms. This approach is usually now reserved for the highest risk systems – for example, farms which have recently had severe clinical PGE with significant pasture contamination and no low-risk pasture available - and it is not recommended to use this strategy routinely without vet advice.
‘Targetted therapeutic’ Treatment systems involve using a combination of growth rat monitoring and FWECs to target anthelmintic use, usually in conjunction with your vet or SQP. When worm treatment is indicated this may be needed for the group or just for individuals showing clinical signs/poor growth. This can work well in low-risk systems, and while it can be more labour-intensive, it can significantly reduce the amount of anthelmintic used, reducing the likelihood of AR developing on your farm.
Treatment options
These include:
How to administer wormers correctly
To provide the most effective treatment and limit the risk of developing anthelmintic resistance (AR) on your farm, it is important to ensure you are administering your wormers correctly. This involves;
- Making sure you are using the correct product for both the species you are treating and the parasites you are targeting. Ensure that you have the correct equipment to administer the product.
- Storing the product correctly (according to manufacturer instructions), using it before the expiry date and note any risks or precautions before use, as well as the meat withdrawal of the product.
- Accurately weighing your animals with weigh scales or a weight tape – inaccurate weights can lead to underdosing – your treatment may be ineffective leaving behind some worms that have been exposed to wormer but not killed (resistant); or overdosing – a waste of the product and your money as well as potential for drug side effects.
- Calibrating your dosing gun/syringe before each day’s use to ensure you are delivering the right dose of product to each animal.
- Keeping accurate treatment records.
More information on this can be foundat; Administering-wormers-anthelmintics-effectively.pdf(cattleparasites.org.uk)
Other treatments that may be required
Treatment and quarantine of bought-in animals to reduce the possibility of resistant worms entering the farm.
Treatment of first-season youngstock at housing reduces the likelihood of type II disease developing and will reduce pasture contamination at the beginning of the next grazing season. It is possible to use a combination product to also treat fluke, lice etc if required. Treatment should be an ML (clear) or certain typesof BZ (white), to ensure that dormant larvae are killed as well as adult worms. Yellow drenches are NOT effective against the larval stages.
Minimising worm burdens in beef youngstock
Pasture management can be used to minimise the risk of pasture contamination with worm eggs and larvae. The first step would be to identify the highest-risk pastures (those grazed by youngstock in the last 6 months, with no sequential grazing by sheep).If naïve youngstock must be grazed on these high-risk pastures, then there are several options for reducing the risk of severe worm burdens:
- Rotational grazing systems.
- Co-grazing/sequential grazing with other species e.g. sheep can reduce overall pasture contamination.
- Follow-on systems – young naïve animals graze clean pastures first, followed by adult cattle with higher levels of immunity.
- Saving lowest-risk pastures forlate summer – by late summer there is likely to be a build-up of worm eggs in pastures that youngstock have been grazed on. Moving them to graze silage aftermath/new leys/other low-risk pasture from late summer onwards will lower the risk of clinical disease.
- Healthy soil – good soil management will increase the populations of earthworms, dung beetles and other organisms which can help to destroy worm eggs or inhibit larval growth.2
- Delaying turnout until pasture worm burdens have reduced – while this is not an ideal option for grass-based producers it may be required in the short term in herds with severe worm problems where the only option for grazing is exceptionally high-risk pastures.
References:
1. Geurden T, Chartier C,Fanke J, di Regalbono AF, Traversa D, von Samson-Himmelstjerna G, Demeler J,Vanimisetti HB, Bartram DJ, Denwood MJ. Anthelmintic resistance to ivermectinand moxidectin in gastrointestinal nematodes of cattle in Europe. Int JParasitol Drugs Drug Resist. 2015 Aug 18;5(3):163-71. doi: 10.1016/j.ijpddr.2015.08.001.PMID: 26448902; PMCID: PMC4572401.
2. Szewc M, De Waal T, ZintlA. Biological methods for the control of gastrointestinal nematodes. Vet J.2021;268:105602. doi:10.1016/j.tvjl.2020.105602
Other sourcesused for this blog:
roundworm-140120.pdf(cattleparasites.org.uk)
Gut and LungWorms - COWS - Promoting Sustainable Control of Cattle Parasites
NADIS - PGE in Cattle| NADIS Forecasts
AHDB - Parasitecontrol guide | AHDB
Administering-wormers-anthelmintics-effectively.pdf(cattleparasites.org.uk)
Gut worms in beef youngstock – treatment and tips to reduce the development of resistance
- Worming beef youngstock
- Treatment options
- How to administer wormers correctly
- Other treatments that may be required
- Minimising worm burdens in beef youngstock
Historically, gut worms in cattle have been controlled with regular, routine worming treatments, without always thinking about whether wormer treatments were necessary. We know from the sheep industry that unnecessary worm treatments contribute to the build-up of wormer resistance which has significantly limited the wormer classes available to some farms. The issue of wormer resistance has not been as well documented in cattle- we need to be thinking ahead and aiming to control gut worms in beef cattlein a targeted way to delay the build-up of resistance in the worm population. The range of wormer drugs licensed for cattle is much more limited than for sheep, meaning we need to use the drugs we have responsibly whilst effectively controlling disease.
If you want to know more about which gutworms affect beef youngstock please read our other blog – ‘Gut worms in beef youngstock –which worms are a problem and how to diagnose them’.
Worming beef youngstock while at grass
‘Preventative’ Treatment systems have commonly been used where pastures are consistently grazed, not rotated. It aims to treat at the beginning of the grazing season, within the 1st 3 weeks of turnout, to reduce the number of worm eggs shed onto the pasture. Products used are often long-acting– such as injectable ML’s. This approach requires less handling and diagnostic testing but can select heavily for anthelmintic resistant (AR) worms, an increasing problem in UK sheep flocks and starting to be diagnosed in cattle farms.1This approach can also lead to ‘overworming’, causing a lack of immunity to both gut worms and lungworm.
It is rare for healthy cattle aged over two years old to require any treatment for gut worms. This approach is usually now reserved for the highest risk systems – for example, farms which have recently had severe clinical PGE with significant pasture contamination and no low-risk pasture available - and it is not recommended to use this strategy routinely without vet advice.
‘Targetted therapeutic’ Treatment systems involve using a combination of growth rat monitoring and FWECs to target anthelmintic use, usually in conjunction with your vet or SQP. When worm treatment is indicated this may be needed for the group or just for individuals showing clinical signs/poor growth. This can work well in low-risk systems, and while it can be more labour-intensive, it can significantly reduce the amount of anthelmintic used, reducing the likelihood of AR developing on your farm.
Treatment options
These include:
How to administer wormers correctly
To provide the most effective treatment and limit the risk of developing anthelmintic resistance (AR) on your farm, it is important to ensure you are administering your wormers correctly. This involves;
- Making sure you are using the correct product for both the species you are treating and the parasites you are targeting. Ensure that you have the correct equipment to administer the product.
- Storing the product correctly (according to manufacturer instructions), using it before the expiry date and note any risks or precautions before use, as well as the meat withdrawal of the product.
- Accurately weighing your animals with weigh scales or a weight tape – inaccurate weights can lead to underdosing – your treatment may be ineffective leaving behind some worms that have been exposed to wormer but not killed (resistant); or overdosing – a waste of the product and your money as well as potential for drug side effects.
- Calibrating your dosing gun/syringe before each day’s use to ensure you are delivering the right dose of product to each animal.
- Keeping accurate treatment records.
More information on this can be foundat; Administering-wormers-anthelmintics-effectively.pdf(cattleparasites.org.uk)
Other treatments that may be required
Treatment and quarantine of bought-in animals to reduce the possibility of resistant worms entering the farm.
Treatment of first-season youngstock at housing reduces the likelihood of type II disease developing and will reduce pasture contamination at the beginning of the next grazing season. It is possible to use a combination product to also treat fluke, lice etc if required. Treatment should be an ML (clear) or certain typesof BZ (white), to ensure that dormant larvae are killed as well as adult worms. Yellow drenches are NOT effective against the larval stages.
Minimising worm burdens in beef youngstock
Pasture management can be used to minimise the risk of pasture contamination with worm eggs and larvae. The first step would be to identify the highest-risk pastures (those grazed by youngstock in the last 6 months, with no sequential grazing by sheep).If naïve youngstock must be grazed on these high-risk pastures, then there are several options for reducing the risk of severe worm burdens:
- Rotational grazing systems.
- Co-grazing/sequential grazing with other species e.g. sheep can reduce overall pasture contamination.
- Follow-on systems – young naïve animals graze clean pastures first, followed by adult cattle with higher levels of immunity.
- Saving lowest-risk pastures forlate summer – by late summer there is likely to be a build-up of worm eggs in pastures that youngstock have been grazed on. Moving them to graze silage aftermath/new leys/other low-risk pasture from late summer onwards will lower the risk of clinical disease.
- Healthy soil – good soil management will increase the populations of earthworms, dung beetles and other organisms which can help to destroy worm eggs or inhibit larval growth.2
- Delaying turnout until pasture worm burdens have reduced – while this is not an ideal option for grass-based producers it may be required in the short term in herds with severe worm problems where the only option for grazing is exceptionally high-risk pastures.
References:
1. Geurden T, Chartier C,Fanke J, di Regalbono AF, Traversa D, von Samson-Himmelstjerna G, Demeler J,Vanimisetti HB, Bartram DJ, Denwood MJ. Anthelmintic resistance to ivermectinand moxidectin in gastrointestinal nematodes of cattle in Europe. Int JParasitol Drugs Drug Resist. 2015 Aug 18;5(3):163-71. doi: 10.1016/j.ijpddr.2015.08.001.PMID: 26448902; PMCID: PMC4572401.
2. Szewc M, De Waal T, ZintlA. Biological methods for the control of gastrointestinal nematodes. Vet J.2021;268:105602. doi:10.1016/j.tvjl.2020.105602
Other sourcesused for this blog:
roundworm-140120.pdf(cattleparasites.org.uk)
Gut and LungWorms - COWS - Promoting Sustainable Control of Cattle Parasites
NADIS - PGE in Cattle| NADIS Forecasts
AHDB - Parasitecontrol guide | AHDB
Administering-wormers-anthelmintics-effectively.pdf(cattleparasites.org.uk)