Thursday, July 18, 2024
HomeGrazier's Focus of the MonthYour Livestock Can Help You Win the War on Weeds

Your Livestock Can Help You Win the War on Weeds

This month we’re focusing on weeds and the way we think about them. In fact, my goal is that you start appreciating them for what they are: quality forage. I know this is a hard thing to do, so I’ll start with a story about how I found out that weeds are great.

It Started With a Goat

In 1996 I was working for the Bureau of Land Management. As part of my duties, I was acquainting our local community with the resources we managed by taking folks on weekend hikes. Participants always showed up unprepared – not enough water, no sunscreen, no snacks – so my pack was always heavy with extra supplies. To make my life easier and more interesting I bought a pack animal: a goat named Cisco.

From one goat, I went to two, and then 15, and then 50 and then 110 ­– a grazing workforce as part of a research project to build firebreaks. I went from looking at grass as forage, to seeing everything as potential food. And, like many crazy goat people, I began extolling goat virtues to the cattle ranching community. Why, there was even research showing that five goats per every cow in a pasture would reduce weeds and improve the quantity and quality of forage for both goats and cows!

This was their response:

They were right. I was wrong. Goats require different infrastructure and different marketing so adding them to a ranching landscape just didn’t make sense.

Fred Provenza (center) headed research to find out why animals eat what they eat. You can read more about his work here.

But graziers still had a weed problem, so I decided to modify my approach. Colleagues at Utah State University studying how animals choose what to eat had found that they learn what to eat and choose diets based on nutrients and toxins in the foods. “Well,” I thought. “If all that’s true, then I should be able to teach a cow to eat a weed, and that would be a lot easier than getting ranchers to buy goats.”

So, in 2004 I began a pilot project to see if I could actually teach cows to eat weeds. I based my training process on research by Fred Provenza and his colleagues, and on decades-old science describing how animals learn. These are the things I considered:


Most of us grew up believing that palatability is linked to the taste of a food. But Fred’s research showed that taste is simply a reflection of the body’s experience of a food.

Here’s how it works: All plants contain both nutrients and toxins. Nutrients generally send good feedback to the brain, and the brain links that positive experience to the flavor of the food. Nutritious foods taste “good” and the animal will tend to eat more of that food. Foods low in nutrients provide less positive feedback, so they don’t taste as “good.” That’s why high-nutrient, high-calorie ice cream tastes so much better than low-nutrient, low-calorie celery. Meanwhile, toxins provide negative feedback, normally experienced as nausea. The higher the dose of a toxin, the more negative the feedback and the less the animal eats. The brain links the taste of the food to the negative feedback and labels that flavor “bad.”

That meant my weeds had to be nutritious in order to be delicious. And as found out, they are. Most are equal to or better than grass in quality and also low in toxins.

Getting an Animal to Try a New Food

Now, here’s the real problem: how to get a cow to take a bite of a weed.

To different degrees, we’re all afraid of trying new things. But when I looked at animal behavior research, I learned that the more positive experiences animals have with new things, the more likely they are to try other new things. Along with that, I thought about Pavlov’s dog who learned from routine that every time the bell rang, he was going to get fed. I combined these two ideas to create a routine where animals tried so many new things that new became normal and not scary.

Here’s what the routine looks like: I drive up in the same truck, at the same time twice a day, and put an unfamiliar but nutritious snack in the same tubs. I do this for four days, giving the trainees eight different foods to try. Why eight? After a close look at data from Fred’s experiments, I could see that seven to eight experiences were what it took for animals to be comfortable with something new.

Trainees are quick to learn the routine, and they figure out that every time I show up, I’m going to give them something tasty. As I watched how they behaved, I also learned that peer pressure could help me get where I was going. By using one tub for every three animals, they were quicker to grab what they could get before the next cow could eat it all.

On day five, I can introduce the weed – just another new food in a series of new things. They try it like they’ve tried everything else, get the good feedback from the nutrients, and they’re ready for the next step.

Because the training process is based on animal behavior principles, it works with any animal. I’ve even used it to teach people to eat fried meal worms. When I’m speaking at a workshop, I periodically toss out candy to participants who ask questions. After I do this for awhile, I introduce little boxes of fried meal worms. At first, folks are hesitant. But then I tell them, “Everyone else has ate them!” One person tries a little bit, then tells everyone else they’re tasty and Ta Da! I’ve got a room full of meal worm eating humans.

Want to see the training process in action?

Here you go – a video from a training I did in Boulder County, Colorado. (Please note that I’m working on a 500-acre pasture. The only road accessible part of it was also a former coal mine, and that’s why it’s not very attractive. The rest of the pasture was a typical healthy Colorado pasture.)

Learning to graze a weed in pasture

Just like animals learn what to eat, they also learn how to eat. Again, Fred’s research looked at this aspect of grazing because they noticed in one of their studies that some animals did better at eating blackbrush than others. The discovered that those with experienced Moms learned faster than those without. This didn’t seem like something I could address with training, so I simple rely on the animals to experiment and learn on their own.

Ta Da! It Works!

In every training I’ve done, there’s a moment when I wonder, “Will it really work?” And every time it does work. That’s because the process is based on science turned into simple steps that anyone can use. They’re basic principles that I’ve used to train cattle, sheep goats and even a herd of Ted Turner’s bison to eat a wide variety of weeds. I’ve helped 4th generation graziers and new landowners and worked with as few as 10 trainees to as many as 110 cow/calf pairs. Again, no matter who does it, or which animals they choose, it works.

What Could Weed-Eating Livestock Mean to You?

Great – it works. But what happens when I tell folks their cow can eat weeds?

I worked hard for over a decade to help folks see how much better their lives could be if they just took a few hours to train a few animals to eat weeds. But I have to say, farmers and ranchers are much harder to train than cows, goats or sheep. Still, I haven’t given up.

Here’s what’s in it for you:

The first thing you get when your cows begin eating weeds is more, high quality forage. It’s a big step for us to start thinking of a foe as forage, but when you look at most weeds’ nutritional value, and keep in mind their willingness to come up year after year in spite of drought or not being fertilized, it’s a step worth taking. Economist John Morley estimates that by thinking of weeds as forage, producers with an average weed infestation problem could see a 43% increase in acreage available for their cows.

You can read more about that here:

When Your Livestock Graze Weeds You’ll Have 43% More Forage

Another benefit is a reduction in the time and money spent on weed control. These costs vary from producer to producer and location to location, but eliminating those costs is a sure way to increase profitability.  As Morley says, “We know that the low-cost producer makes more money 100% of the time.”

John Wick and Peggy Rathmann of Nicasio Native Grass Ranch in California sum it up well. John says, “Economically if you’re comparing equipping, supplying, and applying yourself to using herbicides, all you’re doing is focusing on weeds. If you’re training cows to go out, and in addition to all the other beneficial things they’re doing, to also feed themselves on a nutritious plant, it’s all good. There’s no downside to cows.”

You’ve got questions and I have answers

I’ve shared all the training steps in detail in past On Pasture articles. You can find that information here. For even more, you can download the Cows Eat Weeds ebook set. Cows Eat Weeds includes all the background you need, along with problems and solutions to them from my ten years of actively working in the field training livestock across the U.S. and Canada to eat a wide variety of weeds. Edible Weeds & Training Recipe is a supplement that makes sure you’re animals will be safe as you begin.

For answers to the most frequently asked questions, check out this week’s Notes From Kathy. Then stay tuned for more articles on managing weeds using livestock and thoughtful grazing management.

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Kathy Voth
Kathy Voth
I am the founder, editor and publisher of On Pasture, now retired. My career spanned 40 years of finding creative solutions to problems, and sharing ideas with people that encouraged them to work together and try new things. From figuring out how to teach livestock to eat weeds, to teaching range management to high schoolers, outdoor ed graduation camping trips with fifty 6th graders at a time, building firebreaks with a 130-goat herd, developing the signs and interpretation for the Storm King Fourteen Memorial trail, receiving the Conservation Service Award for my work building the 150-mile mountain bike trail from Grand Junction, Colorado to Moab, Utah...well, the list is long so I'll stop with, I've had a great time and I'm very grateful.


  1. This came at just the right time, Kathy. Starting on the 21st I’m going to try it. . . seriously. With so few cows, I can’t possibly justify buying eight different kinds of feed from the feed store. I have beet pulp, alfalfa pellets, and can get corn, oats, barley in small amounts. Is that enough?

    Also, my pastures are very productive and I have only three cows this year. Have you ever worked with this combination of factors?

    I’ll be implementing the program much more seriously than my previous half-hearted tries.

    • That sounds good, Curt. I have worked with pastures that are very productive, so this should work for you. Good luck and let me know how it goes!

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