During the grazing season, worm and fluke parasites are the first two things that spring to mind from an animal health point of view. I think it’s fair to say that if farmers were given three wishes, for most, one of these wishes would be for a dosing plan that could simply eliminate all parasite problems on their farm. Unfortunately, it’s not that easy.
Resistance
It has always been the case that to control worms, administration of a broad-spectrum anthelmintic (wormer) would do the job. In Ireland, despite the huge variation of products, there are in fact only three classes of wormer (Table 1).
Up until recently, there were really only two factors that were considered when picking a time to dose and what product to use – cost and labour. However, now there’s a third factor – anthelmintic resistance.
Put simply, anthelmintic resistance is the ability of a worm to survive something that should kill it. The continued use, and in many cases overuse, of wormers has in time led to worms developing the ability to withstand anthelmintics. Furthermore, the rate of this resistance is increasing because it is a genetically inherited trait.
Research carried out by Dr Orla Keane of Teagasc has shown some worrying results (Table 2). The research was carried out on 24 dairy-calf-to-beef farms nationwide. Of course, dairy calves are more susceptible to gut worms from an earlier stage and are treated more frequently, but the results cannot be ignored from a suckler perspective either.
The three different classes of anthelmintic in Table 1 have different modes of action. However, within a class, all products have the same mode of action. This means that when resistance develops to one product within a class, all the products in the same class are affected.
Our approach towards controlling worms in our cattle needs to be tailored. Recently, a vet compared it to global warming – “We can keep doing what we have been doing and ignore the threat, but at some stage that will come back to bite us.”
An integrated approach is being taken by the Teagasc/Irish Farmers Journal BETTER Farm participants to control stomach worms in calves. This includes grazing management, good nutrition and, most importantly, the appropriate use of anthelmintics.
The appropriate use of anthelmintics involves three factors – when to dose, what product to use and the rate at which to use it. Here we take a look at the BETTER farmers’ decision-making process. The following is very applicable to dairy calf-to-beef systems where calves are grazing from the get-go and have a high exposure to worms on pasture. Since suckler calves have a significantly smaller dependency on grass, gut worms are much less of an issue until closer to weaning but still should be considered nonetheless.
Weighing
I think a lot of good can come from the new BEEP scheme and the requirement that is on farmers to weigh their stock. A group of animals not thriving should raise a red flag. You’re looking for a daily weight gain of over 0.6kg per day in dairy calves and over 0.9kg in suckler calves on average. If your calves aren’t performing when they step on to the scales, or even visually for that matter, it may need further investigation.
Faecal samples
A more telling indictor is faecal sampling. Individual calves can be dung sampled but it is more practical and economical to pool the faeces of some calves within a group to give a good indication of the average number of worm eggs present in the whole group. Best practice when taking a pooled dung sample is to:
Collect samples in the morning, after a period of rest.Take samples from different areas of the dung patch.Collect into sample pots and seal pots in an airtight bag.Take samples from at least 10 animals.Post to the lab within 24 hours, ideally early in the week.Do not freeze, store in fridge or store in direct sunlight.When interpreting the results of the sample for gut worms, you are looking at the strongyle measurement. The measurement is then given as the number of eggs per gramme (epg). Many reports will also give coccidia, liver fluke, lungworm, monieza, nematodiris, rumen fluke and strongloides but be sure to check whether these were actually tested for or not – usually a lungworm test will be more expensive and take longer.
The gut worm burden of your group will then be determined as follows:
Negative / <50 epg – none or present at very low levels – no need to treat.50-200 epg – present at low levels – monitor in two to three weeks’ time.>200 epg – substantial presence – anthelmintic potentially required but consider clinical signs and animal performance first.If you believe worming is required, the best step is to consult your vet and make a decision on what product to use based on cost, labour and of course anthelmintic resistance. If you are only dosing for gut worms, use a targeted product. Often times you may need to treat for lungworm or fluke at the same time and a combination product would then be the best option.
Table 3 shows the faecal sample results from some of the BETTER farms and their mode of action.
Martina Harrington, Teagasc.
Anthelmintic resistance is of huge concern to the beef industry, especially in light of the results seen in Dr Orla Keane’s work. It is therefore critically important that farmers inform themselves on the issue and then use best practice when choosing and dosing with anthelmintics. That means using faecal egg samples to determine if you need to dose and what you need to dose for. Storing your dose correctly, shaking the dose before use, ensuring your dosing gun is giving the correct amount and dosing to the heaviest animal etc are other considerations around responsible use. Of course it brings extra work, but ask yourself, if the worms on my farm become resistant to all three classes, what can I do then?
During the grazing season, worm and fluke parasites are the first two things that spring to mind from an animal health point of view. I think it’s fair to say that if farmers were given three wishes, for most, one of these wishes would be for a dosing plan that could simply eliminate all parasite problems on their farm. Unfortunately, it’s not that easy.
Resistance
It has always been the case that to control worms, administration of a broad-spectrum anthelmintic (wormer) would do the job. In Ireland, despite the huge variation of products, there are in fact only three classes of wormer (Table 1).
Up until recently, there were really only two factors that were considered when picking a time to dose and what product to use – cost and labour. However, now there’s a third factor – anthelmintic resistance.
Put simply, anthelmintic resistance is the ability of a worm to survive something that should kill it. The continued use, and in many cases overuse, of wormers has in time led to worms developing the ability to withstand anthelmintics. Furthermore, the rate of this resistance is increasing because it is a genetically inherited trait.
Research carried out by Dr Orla Keane of Teagasc has shown some worrying results (Table 2). The research was carried out on 24 dairy-calf-to-beef farms nationwide. Of course, dairy calves are more susceptible to gut worms from an earlier stage and are treated more frequently, but the results cannot be ignored from a suckler perspective either.
The three different classes of anthelmintic in Table 1 have different modes of action. However, within a class, all products have the same mode of action. This means that when resistance develops to one product within a class, all the products in the same class are affected.
Our approach towards controlling worms in our cattle needs to be tailored. Recently, a vet compared it to global warming – “We can keep doing what we have been doing and ignore the threat, but at some stage that will come back to bite us.”
An integrated approach is being taken by the Teagasc/Irish Farmers Journal BETTER Farm participants to control stomach worms in calves. This includes grazing management, good nutrition and, most importantly, the appropriate use of anthelmintics.
The appropriate use of anthelmintics involves three factors – when to dose, what product to use and the rate at which to use it. Here we take a look at the BETTER farmers’ decision-making process. The following is very applicable to dairy calf-to-beef systems where calves are grazing from the get-go and have a high exposure to worms on pasture. Since suckler calves have a significantly smaller dependency on grass, gut worms are much less of an issue until closer to weaning but still should be considered nonetheless.
Weighing
I think a lot of good can come from the new BEEP scheme and the requirement that is on farmers to weigh their stock. A group of animals not thriving should raise a red flag. You’re looking for a daily weight gain of over 0.6kg per day in dairy calves and over 0.9kg in suckler calves on average. If your calves aren’t performing when they step on to the scales, or even visually for that matter, it may need further investigation.
Faecal samples
A more telling indictor is faecal sampling. Individual calves can be dung sampled but it is more practical and economical to pool the faeces of some calves within a group to give a good indication of the average number of worm eggs present in the whole group. Best practice when taking a pooled dung sample is to:
Collect samples in the morning, after a period of rest.Take samples from different areas of the dung patch.Collect into sample pots and seal pots in an airtight bag.Take samples from at least 10 animals.Post to the lab within 24 hours, ideally early in the week.Do not freeze, store in fridge or store in direct sunlight.When interpreting the results of the sample for gut worms, you are looking at the strongyle measurement. The measurement is then given as the number of eggs per gramme (epg). Many reports will also give coccidia, liver fluke, lungworm, monieza, nematodiris, rumen fluke and strongloides but be sure to check whether these were actually tested for or not – usually a lungworm test will be more expensive and take longer.
The gut worm burden of your group will then be determined as follows:
Negative / <50 epg – none or present at very low levels – no need to treat.50-200 epg – present at low levels – monitor in two to three weeks’ time.>200 epg – substantial presence – anthelmintic potentially required but consider clinical signs and animal performance first.If you believe worming is required, the best step is to consult your vet and make a decision on what product to use based on cost, labour and of course anthelmintic resistance. If you are only dosing for gut worms, use a targeted product. Often times you may need to treat for lungworm or fluke at the same time and a combination product would then be the best option.
Table 3 shows the faecal sample results from some of the BETTER farms and their mode of action.
Martina Harrington, Teagasc.
Anthelmintic resistance is of huge concern to the beef industry, especially in light of the results seen in Dr Orla Keane’s work. It is therefore critically important that farmers inform themselves on the issue and then use best practice when choosing and dosing with anthelmintics. That means using faecal egg samples to determine if you need to dose and what you need to dose for. Storing your dose correctly, shaking the dose before use, ensuring your dosing gun is giving the correct amount and dosing to the heaviest animal etc are other considerations around responsible use. Of course it brings extra work, but ask yourself, if the worms on my farm become resistant to all three classes, what can I do then?
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