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Voth trains cattle to eat weeds to meet nutritional requirements, manage pastures

by Wyoming Livestock Roundup

Cattle can be trained to eat weeds, the author of Cows Eat Weeds explained to a group of ranchers. 

According to Kathy Voth, who has her own company, Livestock For Landscapes, cows can gain 2.2 pounds per day on forages with 16 percent protein. 

Additionally, cattle can also meet or beat that percentage once they are trained to eat weeds like Canada, Musk, Italian, Russian and Milk thistles, Leafy spurge, Hoary cress or Whitetop, kochia, Spotted, diffuse and Russian knapweeds, Field bindweed, Pigweed, Ragweed, Curly dock, Goldenrod, Lambquarters and Wild Licorice.

Nutritional value

In her work teaching cattle to eat weeds, Voth has found these plants can have better nutritional value than grass. 

“If they are grazed at the right time, weeds can hold their nutritional value better than grass, so why do we think of these plants as weeds? What we should be doing is looking at weeds as forage that we haven’t yet taken advantage of,” she said. “From the standpoint of raising them, they are a cheap feed source because they will always come back.”

It can be expensive to rid pastures of weeds. Some researchers estimate costs to remove weeds at as much as $65 an acre. Figuring 10 acres to graze one cow, that is the equivalent of $650 per cow per year, she explained. 

“So, why should a cow eat weeds?” Voth asked the producers. “The answer is because they can.” 


In cattle production, Voth said quantity, quality and cost of forage are the limiting factors of how many cows a producer can raise, which determines how much is made by the producer. 

“Research has shown, on average, everybody has about one-third of their pasture made up of weeds,” she said.  

According to economist John Morley, “The average pasture is 30 percent weeds. If cows ate just 70 percent of those weeds, producers would have 43 percent more forage.” 

Voth added, “Weeds are nutritious, available when other forages might not be and could be part of a diverse, sustainable landscape.” 

In addition, the high protein forages help the rumen process lower quality plants and put on weight faster.

Developing the diet

“The mother cow is the most important factor in what a young animal will eat,” Voth said. “Cows eat what their moms ate. The reason they won’t eat certain foods is all in their head.” 

Voth referred to a study she conducted where lambs and their mothers were split into two groups, and the pairs were fed either Russian olive or Canadian thistle. When the two test groups were put back together, the pairs went back to whichever plant they had been eating when they were split, even with both plants present. 

Voth then separated the ewes from the lambs, and the lambs still ate whichever weed they were eating when they were split into groups. 

Good versus bad

Voth admits not everything in a pasture is good for the cows to eat.

“There are some things that cattle should avoid,” she said. “Flavor is a result of palatability itself. Whether they eat it or not is not about taste.” 

Voth referred to a study a professor once discussed of a photo of a steer that was holding a dead rabbit in its mouth. 

In this study, scientists were researching phosphorus-deficient soil. The steer had picked up the dead rabbit and ate it because it was deficient in phosphorus, and the steer knew the rabbit had phosphorus in its bones. 

“It is interesting that animals can figure out when they are lacking something, so they will try new things,” Voth said. 

Taste changes over time depending on the animal’s needs, such as pregnancy or age of animal. Animals can figure these things out and mix their own diet. 

Training cattle

Producers who want to train their cattle to eat weeds will need to have an open mind, Voth said. 

“Body language is very important. If producers think what they are feeding the cattle is not good for them, their cattle will know and will not eat it. Producers have to believe what they are feeding them is good for cattle,” she said.

To train the cattle to eat weeds, Voth said the weeds should be green and growing, so they are nutritious. 

She only introduces one weed to their diet at a time. 

“Every single plant has some kind of toxin in it, but very few will kill an animal outright,” she explained.  

Voth said producers can refer to the internet find a list of plants that cattle have eaten or should eat, as well as a list of plants to not teach cattle to eat.

Since Voth started training cattle to eat weeds in the summer of 2004, she has trained over 1,000 cows, sheep and some of Ted Turner’s bison. She works with ranchers who are open-minded and willing to try the process to make their operation more profitable. 

Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to

Teaching cattle to eat weeds

To teach cattle to eat weeds, Kathy Voth, owner of Livestock for Landscapes, likes to teach about 50 animals at a time. 

“It is an easy number that will match well with my resources,” she said. 

The first step is to make the new seem like normal. She feeds the group morning and afternoon for four days. 

“I will feed them an unfamiliar, but, nutritious, food,” Voth mentioned, adding that she uses a different feed for each feeding to get them used to eating something different.

Using empty lick tubs, Voth dumps in one of the unfamiliar feeds like millet, bran, rye or beet pulp. She uses one 50-pound bag per feeding for 25 animals. Voth uses empty lick tubs because more than one cow can get their head inside at once, and they can’t see what the others are eating, which makes them more willing to try new things.

On day five, Voth skips the morning feeding. 

In the afternoon, she will clip enough of the weed she wants to introduce to loosely pack a lick tub. She puts the weeds on the bottom and dumps the feed on top. In this strategy, she likes to use wheat bran because it’s floury and coats the weeds to help get them to start eating it. The wheat bran also sinks to bottom of tub, and cattle really like it, she said. 

“At this point, they are used to me bringing them strange things to eat, so they look at it as one more strange thing to try,” she said.

Voth continues this process on day six, and on day seven, she feed the weeds alone. By then, Voth said producers need to pay attention to the target weeds in their pasture, so they can monitor when the cattle start eating it. 

“When they do, training is done,” she said.


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