Training Your Cow to Eat Weeds
How to Train Your Cattle (Or Other Grass Eater) to Eat Weeds 
Below is a short summary of two teaching methods for training cattle to eat weeds. Both methods rely on convincing your cow or other ruminant that the weeds are a special treat. Once the female cow learns to eat weeds she will teach her babies and other animals, including steers and bulls, to eat weeds. Of course you can try to train steers or bulls too, research just shows that young female bovines learn the fastest (we will let you make of that what you will).
Susan’s Lazy Grower’s Method:
1) Feed cattle bucketfuls or handfuls of tender green weeds, such as chickweed, Sheppard’s purse, or dock, along with some grass. I just dump the weeds and grass in piles. This works especially good during the dry part of the summer when grass in the pasture is not very lush. Cows start associating weeds with special treats and will begin waiting for them when you enter the field to weed. Sometimes they wait patiently and sometimes they all start mooing at you! It is hard to ignore the staring!
2) Gradually start incorporating ‘tougher’ weeds such as Canada thistle or spotted knapweed in with the tender tastier weeds. It may take a short while but the cows will start eating the thistles too. I found they were more eager to try them during the summer when the grass is tougher.
3) If your cows are especially picky eaters, mix in some molasses with the prickly weeds for a little while to encourage consumption (I didn't’t do this but I had all summer to teach the cows).
Picture: Sammy chows down on a tasty Canada thistle. They normally eat them from the bottom up.
4) I knew my training was a success when I saw our cattle herd run straight for a patch of Canada thistle and eat it to the ground (believe me, that sight will bring tears to any grower’s eyes!).
5) Now the cows help control weeds in their pasture. We have noticed a big decrease in weed numbers. They also teach their calves to eat weeds. Weeds are a great food source for cattle.
For Edna's story about Susan and Sammy the cow see Women vs. Weeds.
When I looked up training cows to eat weeds to see if there were other methods of training, I found Kathy Voth's website. Kathy is an expert in convincing picking bovines to start chowing down on weeds and consults with ranchers on how to teach their herds to clean their pasture.
Kathy Voth’s Method (works well with pickier animals and is a lot quicker than my method):
1) Feed cattle a different treat, such as grain or cubed alfalfa or other special food, in feeders for 4 days. Cattle will associate treats of all sorts with the feeders and will learn to eat new foods.
2) On the 5th to 7th day mix weeds with the grain in the feeder. Some researchers have also coated weeds with a little molasses to encourage them to be thought of as treats. Within 2 days the cattle will eat plain weeds.
3) Let the cattle into a small weedy area to practice their new skills for several days before putting them back in the main pasture.
4) For more information on Kathy’s method check out her book Cows Eat Weeds (which sounds really interesting), her DVDs on teaching cows to eat weeds or her website Livestock for Landscapes.