Barber Pole Worm Management Without Dewormer| Snowdrop Farm

If you are interested in reading other parts of this series:

In our last installment of our series about barber pole worms, we looked at what they are and why they are so important to manage in our small ruminant flocks. Most importantly, we learned how to know if your sheep or goats have them. Since barber pole worms can be so deadly to small ruminants it important to understand their lifecycle. In this article we will look at how we can manage our animals to reduce their risk and exposure.

On most farms, the first line of defense against barber pole worms is dewormer. Unfortunately, we are developing serious dewormer resistance problems in this country and throughout the world. There are no new dewormers being developed. We are rapidly realizing that using dewormers to manage barber pole worms is only going to be a temporary fix. Our heavy reliance on them for the last 70 years might have been a mistake. This is a topic we are going to cover in more detail in our next installment of this post.

But for now we will just say, that if your animal has a dangerous amount of parasites, we can give it a dewormer to kill the parasites. However, this is just a very temporary fix to a much larger problem. In a few weeks time your sheep could have just as many worms, and be in the same situation as they were prior to deworming. Unlike in the past, we can no longer just keep giving every single animal a dose of dewormer every few weeks.

So let’s take a look at the barber pole worm’s life cycle, and how we can go about managing it with out dewormers.

Where do they come from?

This is where your sheep pick up worms from!

To begin, we need to understand how our sheep are getting worms in the first place.

Barber pole worms are living in your sheep’s stomach. Their eggs are being excreted in manure. Once this manure is on the ground, the eggs hatch into larvae that your sheep eventually consume completing the life cycle.

The cycle is very simple. The management of it less so.

Firstly, barber pole worm eggs can hatch and complete their life cycle very quickly. In favorable weather conditions of warmth and humidity, it can take only 3-4 days for an egg dropped in manure to turn into an infective larva ready for your sheep to consume. These conditions occur from May to September, or even longer in more southern portions of the country. Once the sheep has eaten the larvae they migrate to the stomach and set up shop. They then start sucking your sheep’s blood, and can rapidly cause anemia and death if more than 500 worms are present.

To make matters worse, barber pole worms are extremely good at laying eggs. One barberpole worm may lay up to 10,000 eggs per day. So even the presence of one worm can contaminate your pasture with a lot of potential parasites. Though not every egg will survive to become an infective larvae, it is important to understand that even under less than ideal conditions more than enough of these eggs will likely survive.

Once they become the infective larvae found on grass, they are extremely tough and hard to kill. In fact, they can lay waiting in your pasture for 6 months or more. They just sit there waiting for your sheep to consume them.

The short grass in this pasture provides the perfect conditions for sheep to pick up tons of parasites

As if they needed an additional survival technique

The barber pole worms know that their eggs and early larvae will be killed during freezing weather. When the weather gets cold in the fall worms in your sheep’s stomach will be triggered to turn into dormant cysts burrowed in the stomach wall. These cysts sit and wait patiently for spring ensuring barber pole worms survive to live another year.

When your ewes get close to lambing, they experience something called the periparturient rise in egg shedding. Essentially, lambing triggers a drastic increase in the worm and egg production in your ewes. All the dormant worms in your sheep’s stomach become active again. Additionally, their immune system is suppressed allowing more new worms to attach and shed eggs.

This ensures that your ewes contaminate the pasture with fresh healthy larvae. It also ensures that your vulnerable lambs will be infected to keep the worm cycle going.

So what can be done?

This information about the barber pole worm’s lifecycle gives us some hints about how we can reduce risk through our management practices. It is quite obvious that reducing our animal’s exposure to manure is the way to reduce their exposure to barber pole worms. The question is how do we do this?

It can be very difficult to do entirely, but there are some things that you can do to help.

Firstly, don’t feed your sheep on the ground. Sheep will poop anywhere and everywhere. If they are getting hay or grain, put it up in a feeder where they can’t poop on it. This way they are not eating in the same place they poop.

An example of a hay feeder we use to keep our sheep from eating off the ground

Dry lots can be very helpful!

Another way you can reduce exposure is to keep your animals on a dry lot. A dry lot is a small paddock that has no grass in it. NONE. No weeds, nothing. It should also be constructed in a manner that it stays dry and easy to clean. Feed your animals up of the ground. Clean your dry lot at least every few days to remove the manure before the worm eggs have a chance to develop into infective larvae.

Now we know not everyone wants to keep their animals on a dry lot eating expensive hay year round. This isn’t the solution if you want pasture raised grass fed animals. Regardless, in a pasture based system dry lots can still be a useful tool.

For example, do you have animals struggling with parasite burdens? It is an excellent idea to remove them from pasture and put them in a dry lot while they recover. It is also a good idea to put your sheep into a dry lot in the winter months when you are feeding them hay. This way they are not dropping worm eggs on your pastures all winter long. Because as we know less fresh worm eggs on pasture = less parasites out there come spring.

Sheep on a temporary dry lot made using electrified netting

So what else do we know?

We also know that our lambs are the most vulnerable to parasites. Thus it would obviously be ideal to be able to turn our most vulnerable young lambs out onto a pasture that doesn’t have a huge parasite load.

So how can you go about accomplishing this when it can take 6-8 months or more for all the larvae to die?

First we should mention in case you are wondering based upon the information above, no. Winter does not clean your pasture of parasites. New eggs and early stage larvae will likely be killed by freezing temperatures. However, the infective larvae can overwinter in a pasture. They can actually live longer in cool weather because their metabolism is slower. You won’t accumulate new parasites as readily during the winter months. Nonetheless, the ones left over from the end of the summer are likely still lying in wait.

So how DO we manage our pastures to lower the parasite levels?

There are a few different directions you can go with pasture management. They all come with pros and cons, and you will have to determine what works best for your particular situation.

Probably the most common method you hear mentioned is rotational grazing. If we move our animals to new pasture every 3-4 days before the larvae become infective, then we reduce our animal’s exposure. You are then supposed to avoid moving them back to that pasture for a minimum of 40 days, or significantly longer in cooler weather. This long rest interval allows many of the larvae to die prior to returning the animals to the pasture.

The problem with this is that for many producers, it is impractical. It requires an awful lot of land to move your sheep that often, and to keep them off for that long.

An alternative to rotating them every few days is to leave them in the pasture longer/return to the pasture sooner. In this scenario, you determine when to rotate based upon the height of the grass rather than the hatch rate of the larvae.

Barber pole larvae has to crawl from the manure up the blades of grass. They aren’t exceptionally athletic, so the majority of the larvae will remain within a few inches of the ground. If you don’t allow your animals to graze your pastures shorter than 6” their exposure will be drastically reduced.

The drawback to this method, is that you can’t explain this concept to your sheep. Your sheep might choose to selectively graze more palatable grass species closer to the ground while ignoring other ones. This means that even if your overall pasture height is greater than 6”, the grass the animals are choosing to actually graze might not be.

If you can’t rotate then reduce

Another suggestion is to reduce your stocking density. Less sheep = less worms. Unfortunately, this once again returns to the theme of needing a lot of land to implement.

One last grazing technique worth mentioning here is multi-species grazing. Barber pole worms do not affect horses or cows, and their parasites don’t infect small ruminants. This means that we can very safely alternate graze to the benefit of both species. If you graze sheep through your pasture, follow with cows. Then return to grazing sheep, and keep alternating all season. The cows will consume the majority of the barber pole worm larvae, and they will fail to complete their life cycle.

This is a concept that you can also apply to grazing groups of sheep at different life stages. It won’t be as effective as using a different species, but still may be worth considering, particularly if you have parasite resistant breeds of sheep.

In this scenario, graze your lambs through your pasture, and the have your adult sheep follow behind. Your lambs are carrying the highest parasite load, and are shedding the most eggs. When the adult sheep follow your lambs, they will consume and their immune system will kill a lot of the larvae the lambs deposited. This will leave you with a cleaner pasture than your young lambs left.

At this point you might be wondering if there is a way to completely get rid of the larvae on a pasture

Unfortunately, under most circumstances it can be very difficult to have ‘clean’ worm free pastures. However, there are a few things that you can do to give you pastures that are clean or as close to clean as possible.

First is the obvious one. Allowing a pasture to go ungrazed for a full 12 months will result in the death of virtually every single parasite. So, if you have enough land to allow one pasture to sit empty each year, you would have a clean area to move your lambs into every spring.

A variation on this theme, is to rotationally use your pastures for hay. For example, take a first cutting of hay off, and then to graze it afterwards. The process of drying and removing the hay nets you a worm free pasture. Once you move your sheep to the pasture you took a first cutting off, allow the pasture they came from to regrow. Remove a 2^nd cutting from that pasture. You can once again move your sheep to a clean pasture for fall grazing.

Annual crops can be very beneficial in a parasite control program

Another thing that you can do is to till and reseed pastures or plant annual forages rather than using perennial grass pastures. As it would turn out the crowns of perennial grasses are excellent places for larvae to overwinter. Tilling up the pasture to plant annual forages turns those larvae into the soil where they will die.

Now, planting annuals isn’t practical for everyone, and if you can grow perennial grasses we definitely wouldn’t recommend tearing up all your pastures. However, if you are struggling with a serious worm problem, renovating a pasture can help you to mitigate it. It can also be a very useful tool if you have enough space that you can plant an annual forage pasture specifically for your lambs every year. If you rotationally graze your lambs across an annual pasture making only one rotation across it (don’t re-graze any of it), you would likely have virtually no parasite problems in your growing animals.

For those of you without vast acreages of land or equipment

Sometimes you have to get creative. Often if we run out of clean pasture late in the summer we will use temporary fence to rotate a group of lambs through our house lawn to graze.

Now, I know that for many people these options are impractical or impossible. Not everyone has acres and acres and acres of land or the equipment to tear up and replant pastures. You will have to do your best to come up with creative ways to manage worms along the lines of these principals and through the tools that you do have available.

The most valuable tool you have at your disposal is genetics. Sadly, for so many years this has been completely overlooked. We have been so reliant on cheap and easy monthly deworming to control parasites that we have forgotten that parasite resistance is an important trait to breed for. With the rise of serious dewormer resistance problems, it is a trait we are beginning to look at more closely. Thankfully, there has been a lot of research on the topic recently. What we have learned is very encouraging.

Because you are managing small flocks, you have the ability to track individual animal performance closely enough to make real improvements. Do not keep wormy animals. 20% of your sheep are carrying 80% of the parasites. If you remove that 20%, then you are removing 80% of the eggs being shed on your pasture. This selective culling greatly benefits all of your animals.

Its up to you to select for valuable traits like parasite resistance

Parasite resistance IS a heritable trait and something that we can easily select for. This holds true for both sheep and goats. It is something that anyone can improve in their flock over time. As a general rule, sheep are probably ahead of goats in this department. There are breeds of sheep like the Katahdin and St. Croix that have reputations for being very parasite resistance. Plus, many big name Katahdin breeders are very actively competing to produce the most parasite resistant sheep.

However, goat owners, and sheep owners of non parasite resistant breeds or flocks should not despair. Research has clearly shown that even if you don’t have a parasite resistant flock to begin with you can significantly improve (or worsen) their parasite resistance based upon how you select your replacement animals.

Parasite resistance, and how we measure and select for it is a very interesting topic we are going to delve deeper into in a future article. However it is something that takes time to make improvements on. Right now you need useful tools to help you manage your current flock. So first, we are going to to take a detour to look at deworming in our next article.

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