This calf is eating musk thistle, just like her mom taught her to do.

One of the common questions I get from folks who hear me talk about training livestock to eat weeds is whether or not it is a good way to control weeds.  For the answer, I’ll share what was in my head when I started trying to figure out the process for teaching animals to try a new food.

1.  Using herbicides is expensive.  Not only is there the cost of the chemical itself, but there’s the cost of the equipment to apply it, along with labor for learning about how to use it, sometimes getting certified to use it, then applying it.  And it’s not a one time cost, but something that is repeated over and over again.

2.  Herbicides don’t appear to be working.  In spite of our best efforts, weed populations continue to expand at about 14% per year.  So it seems like we’re pouring good money after bad.

3.  Producers are often low on forage, particularly in arid areas or during drought.  But weeds are always there, even in drought, AND they’re often higher in nutritional value than traditional grass-based forage.

4.  Margins are pretty low in agriculture and the producers who can reduce costs are the ones who are going to be successful.

5.  SO – If I can figure out how to get a cow to eat a weed, producers can eliminate the expense for weed control, they’ll have more feed at no additional cost, cows gain weight more rapidly when they eat higher protein foods, so farmers will be able to raise more, fatter cows more cheaply and they’ll make more money doing it.

Here’s an example of all those thoughts coming together in one project I did in 2010.  Nate Allington, a rancher in the Burns, Oregon area told me that his father-in-law had paid almost $400 for a gallon of herbicide to spray on Canada thistle.  Nate and I trained his cows to eat Scotch thistle, and then when they went to pasture, they added Canada and bull thistle to their diet. He said they ate them both into the ground.  So now he has cows that will do this every year, he never has to buy the herbicide, and he’s benefiting from the extra forage his cows have.

Cost Benefit Analysis

It turns out that for the one time cost of about $250 in materials and 8 hours over 7 days, a farmer/rancher can train 50 cows.  Those animals train their calves and herd mates, all of them eat first the target weed and then start exploring other weeds.  Over the last 4 years I’ve watched a group of trainees go from eating their normal grass forage, of which there was very little, to eating every single plant in a very, very weedy pasture.  In fact, in this pasture, I just completed a three year demonstration of how to manage cattle to reduce the weeds.  During the first grazing season we started with 100 cattle in a 500 acre pasture, and realized that because of the quantity of weeds they eat now I would need at least 300 to cover the whole pasture adequately.  That seems like a pretty profitable problem to have.

So that’s the cost benefit side of what I was thinking and how it works for a producer’s bottom line.  Here’s a short video of the Economics of Cows Eating Weeds: