Healthy Weeds and Poisonous Plants

Episode 46
For the Love of Goats

 

If you look online for a list of plants that are poisonous to goats, you might think you need to chop down trees and pull up dozens of weeds to keep your goats safe. Those lists can include things like oak and maple leaves, which my goats eat regularly because my farm is covered with them. The fact is that goats actually have a much higher tolerance for poisonous plants than horses and some other animals. So, what’s a conscientious goat owner to do? 

In this episode, I’m talking to Kim Cassida from Michigan State University as we talk about the fact that many weeds can actually be very nutritious for goats while the number of plants poisonous to goats is actually pretty low. 

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TRANSCRIPT

Deborah Niemann 0:18
Hello, everyone, and welcome to another episode. Today, I am really excited that I finally have someone on the show who is going to talk about weeds and poisonous plants as they relate to goats, and also sheep some too. So, if you’ve got sheep, this information will probably be applicable to both. I’m joined today by Kim Cassida, who is a forage and cover crop specialist at Michigan State University. Welcome to the show, Kim!

Kim Cassida 0:47
Hi, and I’m glad to be here!

Deborah Niemann 0:50
So, I was really excited when I got to hear you talk about weeds. And the first thing you said that just really pulled me in was “Goats are not horses,” which really excited me, because a few years ago, I thought I was finally going to get all the information I needed when I visited the poisonous plant garden at University of Illinois with one of their veterinary toxicologists. And, I did not learn nearly as much as I was hoping to learn about goats. But I did learn that the reason so many people think so many things are poisonous to them—which they can eat all day—is because they are poisonous to horses. All these years, I thought that horse owners were just, like, paranoid, because they had these very expensive pets and they, you know, didn’t want anything bad to happen to them. But I actually learned there that horses, in spite of their huge size, are actually very delicate creatures. And their single stomach makes them more susceptible to toxins and stuff than goats and sheep. So, do you want to talk a little bit about that confusion between horses and goats and sheep?

Kim Cassida 2:04
I think what people get confused about is they’re looking at animals that all eat the same kind of diet. So they’re eating hay or pasture, and a lot of times, it’s interchangeable. But the big difference here is that our goats, and our sheep, our cattle and other things, are ruminant animals with a multi-chambered stomach. And that’s where the food goes first. Whereas the horse has a simple stomach like ours; that’s where the food goes first. In the ruminant animal, the food doesn’t become digested the way we think about it until it gets to the fourth stomach, which is the same as the first stomach on the horse, or the only stomach.

Kim Cassida 2:42
So, what happens in the ruminant animals that helps them deal with these toxic plants is that the first three chambers of the stomach are actually involved in fermenting the feed stuff. So there’s a large population of friendly microbes that live in those first stomachs. And those microbes are basically cultivated by the animal in a symbiotic relationship. And they get the first crack at everything that comes in. And what the animal gets to digest is what passes out of those first stomachs, goes into the true stomach, and by the time it gets there, the microbes have detoxified a lot of the compounds that were in the plants. And that is part of what makes our ruminant animals better able to withstand eating a lot of things that would be very harmful to a horse. So, when poisonous plant lists are put together, you know, they’re looking for… I suppose they’re trying to err on the side of safety. So anything that would be toxic to any kind of animal tends to end up on those lists without a whole lot of consideration for whether some other animal might be able to eat it quite readily. And that is indeed what gets us into trouble with a lot of the poisonous plant lists. Don’t feed them to your horses. Not a good idea. But goats and sheep, and in a lot of cases cattle, might do just fine.

Deborah Niemann 4:16
One of the things that I also thought was really interesting was that you had said that “All plants are toxic.” Which, really, I was like, “Oh, yeah,” because when I visited the poisonous plant garden, they pointed out lamb’s quarters. Which I was like, “Oh my gosh, I’ve eaten lamb’s quarters!” Like, that’s one of those weird little weeds that grows in your yard that some friend comes along and says, “Hey, you can eat this stuff.” And I survived. And I’m pretty sure my goats and sheep eat it, too, and it doesn’t seem to bother them. Do you want to talk about that statement, about how “all plants are toxic”?

Kim Cassida 4:52
Well, I made that statement because, if you look at the evolutionary history of plants, it is not usually in their favor to be eaten. So they would prefer not to be eaten, and they have developed various defenses that help prevent that from happening. And one of these things is plant toxins. Because if the animal takes a bite of the plant or eats some of it, and they don’t feel good afterwards, that will tend to convince them not to come back and have some more. Of course, the other thing that plants do to defend themselves is spines and things like that. But some of the most simple compounds that are in the plants can be toxic to animals—if the dose is high enough. I think that that’s the critical part of it. For example, you mentioned lamb’s quarters. So, there’s two things in lamb’s quarters that can be toxic, and one of the items is oxalates, which, if large amounts of oxalates are eaten, they can be toxic to almost any animals. But in small amounts, it’s probably not that bad. And one of the main things that animals refuse to eat that for is because it actually causes a burning sensation in the mouth. So it’s really not that likely that they’re going to eat enough of it to be actually poisoned, because the burning sensation in the mouth is going to stop them from eating it before they eat that much. But the second thing that can be in lamb’s quarters that could be a problem is nitrates. And this is an example of something that’s actually useful to the plant. And what plants do when they are faced with poor growing conditions and a lot of nitrogen in their root environment—because they need nitrogen to make protein—they take it up and store it for later. So, they’ll actually accumulate nitrate in the plant tissue that the plant’s just holding onto for later when the growing conditions are better. But, if the animal comes along and eats that high-nitrate material, the animal can actually be poisoned, because an animal can process a little bit of nitrate in plants but not a huge dose of it. And so sometimes that’s there, and sometimes it’s not there. And a lot of that depends on the growing condition, which is another thing that happens with toxic plants is that sometimes they are only toxic for part of the time. Other times they might be perfectly fine.

Deborah Niemann 7:16
Yeah, I think I remember you said that, like, in drought conditions, some plants can wind up having a problem when they don’t normally.

Kim Cassida 7:26
Uh huh. Yeah. And the nitrates are actually an example of that, because that’s a prime example of it. The plant continues to take up nitrogen, but it doesn’t have enough water to actually grow and get bigger and make more protein. So that’s the prime condition where it would be storing that nitrogen as a nitrate to save it for later. Because the plant knows, in some plant way, that eventually it will rain, and it will be able to grow.

Deborah Niemann 7:52
All right. And then you had a really long list of plants that are found on these poisonous plant lists. And the ones that you said that grow, like, in the Michigan area that are what you call “zero tolerance” plants are, I think, like snakeroot and poisonous hemlock…

Kim Cassida 8:09
Poison hemlock was on my list; I don’t know that we have snakeroot here. But that just brings up the point, though, that the poisonous plants that are going to be in any particular location can be very specific. And I’ve worked in a number of places across the country, and there are places where it seems like everything is poisonous. I think we’re a little bit lucky up here in the upper Midwest, because the numbers of really bad poisonous plants that we have to deal with are a somewhat smaller list than what you have to contend with if you’re in a place such as out in the West, in particular; there’s a lot of poisonous plants out there. My point there is just that it’s very important to know what’s poisonous in your area, and you need to be able to identify the plants that are in your pasture so you know what it is.

Deborah Niemann 9:01
Yeah. I think one of the only people I know who’s lost a goat to poisoning was somebody who lived down South, and there was oleander in her pasture, which—

Kim Cassida 9:11
Oh, that’s a bad one.

Deborah Niemann 9:14
Yeah! Which her goats didn’t touch. Like, they were in there for months, and they never touched it until they had eaten everything else. And then, when there was nothing left, that’s when they went for the oleander. And several of them got very sick, and her buck and I think one or two others died.

Kim Cassida 9:30
Yeah, oleander is one of the very few that I’ve dealt with personally that is actually pretty toxic if they just take one bite. A lot of times when you’re looking at that dose, they naturally have to eat quite a lot of the plant before it’s going to be a problem, but just a few leaves of oleander can be devastating. So. And that’s a common ornamental plant in many places. In fact, a way a lot of livestock get poisoned is because people clip their ornamental plants, and they think, “Oh, well, the animals would like to eat this,” and they’ll throw those clippings over the fence. And sometimes it’s not even the owner; it might be the neighbor throwing the clippings over the fence thinking they’re giving your animals a treat. And then you don’t even know they ate it. So you’re trying to figure out, “What did he get into?”

Deborah Niemann 10:18
Right. Yeah, I know that’s a real problem. I did a show probably nine months ago with somebody who has goats in the city. And she said her biggest problem is people trying to feed her goats. Because they think goats can eat anything.

Kim Cassida 10:34
Yeah, in my experience, goats are actually pretty picky. They’re quite selective about what they eat and what they don’t eat.

Deborah Niemann 10:43
Yes, they definitely can be. One of the things that I think is kind of funny—and I don’t understand this, and maybe you have an explanation for it. Because, I know I always see cherry trees, and I understand that there’s… I think arsenic in the leaves?

Kim Cassida 11:00
Cyanide.

Deborah Niemann 11:00
Cyanide, right, in the leaf.

Kim Cassida 11:02
Yep.

Deborah Niemann 11:02
And, I had actually planted four Nanking cherry bushes in our yard somewhere, and then forgot they were there, and wanted my goats to actually eat all these baby willow trees that were popping up. And so I just put up the ElectroNet so that they could, you know, be in this area and eat, and they completely destroyed my cherry bushes. They ate all the leaves, they stripped the bark, like, there was nothing left of these four bushes by the time I realized what had happened. And nobody got sick, like, they were all fine. Is that just something with that particular variety of cherry, or…?

Kim Cassida 11:44
Well, it’s possible. A couple of things could be going on there. One is that the main danger with the plants that have cyanide is that the cyanide is in a precursor while it’s there in the green plant; it doesn’t actually get turned into toxic cyanide until the plant tissue starts to wilt. So, if the animals come along and they are eating a fresh green leaf, it doesn’t have a chance to do that. So, that could be one part of it. Where people typically will lose animals to cherry poisoning is if a big branch falls off in a windstorm or something and falls in the pasture, and you don’t know it. The leaves will get wilty, and then the animals come and eat them. Because cyanide’s another one of the—”prussic acid” is what that’s usually called—that’s one of the toxins that animals, actually, if they’re exposed to small amounts of it that builds gradually over time, the rumen microbes will adapt to it and are able to detoxify it fast enough that the cyanide doesn’t get into the animal’s bloodstream. It’s when they get a big slug dose of it all at one time, that they’re not used to it, that it can be an issue. And a lot of the toxins are like that.

Deborah Niemann 12:54
Okay, that makes sense. I’d heard that sometimes the green leaves are not poisonous in some plants, but the wilted leaves are.

Kim Cassida 13:01
Mm hmm. Yeah.

Deborah Niemann 13:02
Which is why I was really in a panic one time when I realized that a giant oak branch had fallen into my pasture. Because oak is always on those lists, and my goats eat all of it. They eat the leaves and everything. And, when that branch fell, it was actually buds on the branches, which I thought, “Uh-oh, it might be… Maybe it’s the buds that are poisonous.” And by the time I realized it, like, everybody was there and was completely eating all of it. And, again, nobody got sick. So, is oak really just one of those horse plants that got pushed—?

Kim Cassida 13:44
Oaks can be toxic to other animals, but that’s one of the ones where they are going to have to eat a lot of it. The toxic factor in oaks is tannin—a type of tannin called “hydrolyzable tannin”—and if they have a high enough dose of it, it can be toxic. But it’s probably also another one that animals can gradually adapt to. And there are different species of oats have—”oaks.” I keep saying “oats.” Different species of oaks have different levels of it in them. And again, most of the oak species that you really hear about trouble with that is in the West. Certainly here in the East you see deer will eat oaks, goats will eat them. If that was their entire diet, I don’t think I would recommend that, but a mouthful here and there? I don’t think it’s gonna cause a problem with goats.

Deborah Niemann 14:40
Yeah.

Kim Cassida 14:40
Don’t let your horses eat it.

Deborah Niemann 14:42
Yeah. We have Bur oaks and white oaks mostly, I think, here. And then we also have a lot of maple trees, which I learned horses can have a problem with maples, too.

Kim Cassida 14:56
Toxic to horses. Yeah, the toxic agent in maple trees—and I’m not even sure what that one is—but that one is literally, totally specific to horses. So, it doesn’t appear to be an issue with other types of animals at all.

Deborah Niemann 15:09
Okay. So there’s two parts to what I want to talk today. One is to kind of have people relax a little bit, because I get so many emails from people who, you know, like, “I’m going to get goats, and I am going to rip out all the weeds that are poisonous, and rip out all the trees that are poisonous,” and all this kind of stuff. Which sounds like a really big job. Although I will never forget the email I got from somebody that said that they had just completely brush-hogged their land and wanted to know what to plant for goats. And I was like—

Kim Cassida 15:41
Goats would have loved the brush!

Deborah Niemann 15:43
Yeah! I was like, “I’m really sorry to tell you that you just destroyed, like, the most magnificent goat buffet, probably.”

Kim Cassida 15:53
Yeah, well, I’m sure as… I’m aware a lot of your listeners know that people run businesses just to take goats around and clean up brush. They’re very effective at it.

Deborah Niemann 16:04
Yeah, exactly.

Kim Cassida 16:06
That’s generally what they would prefer to eat. And there’s actually a lot of nutrition in the parts that they eat. So they’re not… A lot of people think that they’re eating brush because they don’t need a good diet. But actually, goats are what we call—in animal physiology—they’re a “concentrate selector.” So, when they’re eating those very tender tips on the brush and the buds, that’s the absolute most nutritious part of that plant. And so that’s the part that they’re going for. And they’re actually eating a diet that’s quite high in quality when they do that. And now, on the other hand, if you try and force them to eat grass, typically they don’t prefer grass, because grass is not as high in quality as what they would be rather eating, which is those tips on the brush. So, in order to get them to eat grass, it’s almost a training process. But you have to make sure that they are still getting all the nutrients they need, because there might not be enough energy in there to keep them going.

Deborah Niemann 17:06
Right. One of the things that I really loved, what you said is that goats don’t specifically need alfalfa or some specific food. What they need are nutrients. And if we look at what we have in our pasture, there are a lot of things in there that have very high nutrient levels. And I saw a list that you had that listed, like, the amount of crude protein like in ragweed is 11%, bindweed is 16%, prickly lettuce 17%, ground cherry almost 14% protein. Which is really great! I mean, that’s so much better than grass.

Kim Cassida 17:42
Than grass, yeah.

Deborah Niemann 17:44
Grass tends to be very low in protein.

Kim Cassida 17:46
And a lot of those broadleaf…. Yeah, those broadleaf plants, too, a lot of times, the structure of the fiber that’s in them is more digestible than the fibrous part of grass. And so, it’s not just the protein; there’s also probably more total digestible nutrients in there than there would be in grass.

Deborah Niemann 18:07
And then, one of the interesting things that I heard you talk about was training goats to eat weeds. Do you want to talk a little bit about how to do that if your goats are not too crazy about eating weeds in your pasture?

Kim Cassida 18:22
Well, to start, I can say a few things about that. I want to make sure I give credit where credit is due, and the talk that I was giving that you heard, I was relaying a method that was created by Kathy Voth. And she has a business, basically, to teach people how to teach their animals to eat weeds. But it’s all based on animal behavior. So animals eat what they’re used to eating. They’re a little like kids in that regard. If you give them something they’ve never seen before, they’re likely to go, “I’m not going to eat that!” And I can’t tell you how many times I’ve seen animals do that with an alfalfa pasture. You know, the most best forage—everyone thinks it’s the best forage there ever was. And I can guarantee you, they may even be used to eating alfalfa hay, but if they’ve never seen it in a pasture and you put them out there, they’re going to turn up their noses and go, “We don’t know what this is. We’re not going to eat it.” And it’s just a behavioral response to be cautious to eat new things. And where animals typically learn what to eat is from copying their mother and their herdmates when they’re growing up.

Kim Cassida 19:29
So, the easiest way to get your animals to eat a wide variety of things is to have mothers that are willing to eat a wide variety of things, and then your job is done for you because those kids will be ready to go. But what Kathy’s method is based on is basically trying to teach the animals to be adventurous in what they eat. And just again, if you want a lot of details, I would recommend that readers go to her website; she’s got a book and would give you all the details here. But it basically is, you bring interesting foods, and you feed it to the animals in their normal feed bucket. So this would be normal animal feeds first. So you go about four days, every day, twice a day, you give them something different, but delicious, in their feed tubs. And so they learn that you only put good things in there and they should run and come and get it when you do. And then, after the four days is up, you go and you harvest some of the weeds you’re trying to teach them to eat, and you mix a little bit of that in the feed tub. And so they come running and they try it, because they’ve learned over the last few days that you only offer them things that are good to eat. And you’ve been giving them a lot of different stuff, so that’s kind of teaching them “Oh, well, it’s not the same old stuff, but I think I’ll give it a try.” And then you’ll do that for a couple days, gradually increasing the amount of weed that’s in there, and typically the animals will just start eating it. And then you can put them back out in the pasture that has the weed in it—in a small area. First you want to put them in a small area with a lot of the weeds so that they taste it out there and go, “Oh, yeah, this is the same stuff that was in the feed bucket.” And then, off they go.

Kim Cassida 21:12
And you don’t have to do this with your whole flock; you only have to train a few animals. She recommends doing it with at least ten animals so you have some competition going on at the feed buckets. But then you could put those animals back out and mix them in with the rest of your flock, and the other animals will watch the trained animals eating the weeds and go, “Hey, we want some of that, too.”

Deborah Niemann 21:38
Yeah.

Kim Cassida 21:39
And pretty soon they’re all eating it.

Deborah Niemann 21:40
They are like children like that. It reminds me of a few experiences I had as a child, where I was convinced that somebody else had a better candy bar than I did, even though they had the same label on them.

Kim Cassida 21:51
Yeah! Exactly.

Deborah Niemann 21:52
You know…

Kim Cassida 21:53
You know, like I offer my dogs a leaf of lettuce or something, and the dog doesn’t really want the lettuce but darn it, they’re not going to let any of the other dogs get that lettuce, so they’re going to eat it.

Deborah Niemann 22:02
Yeah. That is basically how I got my goats to eat alfalfa pellets. You know, initially, I heard you can put them in the feed pan to slow down the does on the milk stand. And when I tried that, it slowed them down all right, because they were picking through to pick out the goat feed and so they could avoid the alfalfa pellets.

Kim Cassida 22:20
Right. Because it was different.

Deborah Niemann 22:21
Yeah.

Kim Cassida 22:22
They were like, “We don’t eat things that are different!”

Deborah Niemann 22:24
Yeah. But then when I added… I put some alfalfa pellets in a pan and set them on the ground. It only takes two or three goats to start eating them for the other goats to go, “Hey, that must be good. I want some.”

Kim Cassida 22:37
Yeah, you know, there really is a competition factor that takes over there. And I actually tried this with my flock of sheep—I have about 30 sheep here. But I also have Canada thistle on my farm, which is one of the weeds that Kathy would say is one of the most easy weeds to teach animals to eat, because it doesn’t have any toxins in it. Its negative feature is the spiny-ness, obviously. But apparently, it actually tastes pretty good if you can get animals to try it. So I basically went through her method with some of my sheep and got them to taste this, and now I watch them out in the pasture. They’ve decided they like it. And they’ve figured out a way to deal with the thorns, which is: They bite it off down near the surface of the ground, and then they pull it into their mouth backwards. And down it goes.

Deborah Niemann 23:26
Wow! That’s smart.

Kim Cassida 23:30
So, they’re just sucking it in like a big piece of spaghetti, and the spines, they’re pointing the other way, and I’m happy and they’re happy. And Canada thistle is one of the ones that has a really good nutritional value. So, you know, I could spend a lot of money trying to fight how to kill the thistle; Canada thistle is really hard to kill. Or, I could just let my animals eat it and get good nutrition from it. And the nice thing about some things like that is if you can get animals actually selecting your weed, they may eat it to death because they think it’s so good.

Deborah Niemann 24:05
Yes. Yeah, when we first moved here on our property in 2002, it had been a horse farm, and it was covered with floribunda roses. And there are zero roses here now.

Kim Cassida 24:18
Right. Yeah, a lot of people use ’em for goats—and sheep are also very good at rose control—or autumn olive, and honeysuckle is a big one around here. None of those are toxic. They’re just… In the case of—oh, brambles is another one that they’ll eat. A lot of these things are spiny and unpleasant, but goats don’t seem to mind the spines as much as some other animals do.

Deborah Niemann 24:44
Yeah. And when I had LaManchas, I noticed they loved the thistle a lot more than the Nigerians. They… I don’t know what the difference was, but they would eat it like candy.

Kim Cassida 24:55
Well, it might be that learning thing, too. Maybe, you know, those came from a line of animals that had—somewhere along the line—someone had learned how to eat thistles and taught everyone else down the line, where the Nigerians didn’t have that.

Deborah Niemann 25:08
Yeah.

Kim Cassida 25:08
And they weren’t picking up from watching the LaManchas.

Deborah Niemann 25:13
Yeah. So this has been really interesting. Before we wrap up, I just want to revisit poisonous plants real quickly and see if there’s anything else that you want to add about that that people should know?

Kim Cassida 25:26
Well, again, I’ll reiterate that it’s very important that you do know what is in your pasture, because there are some things that you should not let your animals eat. And, if you can’t figure that out by yourself, there are guides online now where you can go and describe your weeds and try and identify them. And if you still can’t, get someone from your local Cooperative Extension, or your NRCS—which is Natural Resource Conservation Service—or see if you can get someone to come out and help you understand what you have in there so you don’t inadvertently create a bad problem. But don’t look at those lists of things that are toxic to horses, because you wouldn’t be able to feed your animals anything.

Deborah Niemann 26:14
Right? Yeah. I mean, I’ve had people talk about, like, cutting down oak trees and maple trees. And, yeah, there was not going to be anything left in their pasture by the time—

Kim Cassida 26:24
Right.

Deborah Niemann 26:24
—they were done cutting down everything that was on this list that they found.

Kim Cassida 26:29
Yeah. And you know, there’s a certain benefit to having some trees in your pasture, too. Actually, be probably more concerned about protecting the trees from the goats than protecting the goats from the trees, because they will eat the bark off things they like, and they can—well, you had the experience with your little cherry trees. And I’ve had my sheep do the same thing with a tree that they like, you know, and they don’t—it’s interesting, because they don’t touch some of the trees in my wooded area. But the other ones they think are quite tasty. And they’ll take the bark off overnight.

Deborah Niemann 27:01
Yeah. And I used to think that trees were safe after the trunk was about 5 or 6 inches in diameter. And I learned I was wrong about that.

Kim Cassida 27:11
I also noticed with my sheep that they are apparently aware of when the sugar sap is running in the maple trees in spring, because that’s the only time they chew on the maple trees.

Deborah Niemann 27:21
Oh.

Kim Cassida 27:22
So, they’re into maple syrup, apparently.

Deborah Niemann 27:24
Yeah, you have really smart sheep.

Kim Cassida 27:28
Well, they can probably smell it, I suppose. It’s probably sweet.

Deborah Niemann 27:31
I don’t think… Maybe I just have dumb goats. I don’t think I’ve ever noticed my goats chewing on the maple trees… Wow. All right. I’m going to be paying much closer attention now.

Kim Cassida 27:43
It’s interesting to watch them when you put them into a new section, and, you know, because I rotate my pastures. And I’ll just stand out there when I put them in something new, because I want to see what they eat first. And my sheep, at this point, they appear to have a rather cosmopolitan appetite, because they’ll try almost anything. And a lot of times they’ll go around and sample all the weird stuff before they go to the grass.

Deborah Niemann 28:06
Yeah. Wow, this has been a lot of fun, and very interesting, and I hope that it helps some people to relax a little bit, and that they’re not tempted to go out there and cut down all the trees in their pasture.

Kim Cassida 28:20
Not probably necessary. Unless it’s an oleander!

Deborah Niemann 28:25
Yeah. If you have oleanders, cut those down for sure.

Kim Cassida 28:28
Yeah. And I’m in the process on my property of trying to get rid of some yew bushes, because that’s another one that a lot of animals get poisoned when neighbors throw yew clippings over the fence—which I’m not going to do, but I just don’t like them. I’d rather have nontoxic plants in my landscape.

Deborah Niemann 28:43
Understandable. Well, thank you so much for joining us today! I think a lot of people will get some really good information from this.