Fall and winter grazing can reduce cheatgrass populations, a University of Nevada study has shown.
The research, by rangeland specialists Barry Perryman and Ben Bruce, dispels theories that cheatgrass is only good for spring grazing, that dry cheatgrass has no nutritional value and that cows won’t eat it, anyway.
The two scientists conducted the experiment between 2006 and 2009 at the Gund Ranch near Eureka, NV. The results showed that cheatgrass biomass dropped from 500 lbs/acre to 90 lbs/acre.
The risk of wildfires was reduced, plus perennial grass production improved, says Perryman.
“Over the course of the study, production of perennial grasses increased from 45 lbs/acre to 577 lbs,” he says.
Perryman and Bruce began the research to investigate whether or not the previously held theories were true. Only grazing cheatgrass when it’s green seemed like an impractical solution for large-scale control.
“You can't get enough animals to graze it all, you don't know when it is going to be green, making it difficult to plan, and you don't know how many animals to bring to an area before it is too late,” says Perryman. “Our experiment showed that, once the seeds fell off the plants, the cheatgrass became palatable.”
Perryman also ruled out the notion that dry cheatgrass has no nutritional value.
“The protein content and energy of cheatgrass in the fall is at least as good, if not better, than perennial grasses,” he says. “The protein level fluctuated between 3.5% and 6%, but never went below the 3.5%. Energy levels measured 45% and above.”
Perryman and Bruce began their research by shifting the calving cycle to later in the season. They found that using that system would benefit ranchers, the rangeland and other wildlife.
“Fall grazing is of great benefit to ranchers, giving them another source of forage that previously was not considered nutritious,” says Bruce. “Also, decreasing cheatgrass increases perennial grass growth. We made sure that the cows were in the second trimester before putting them on a cheatgrass diet. This time in their production cycle is less nutritiously damaging. We supplemented their diet with Anipro liquid protein just as ranchers do when grazing with local perennial grasses in the fall.”
He points out that liquid protein supplement not only stimulates the cattle's appetite, but also keeps them in a specific area where the cheatgrass is located.
“Protein stimulates the microbes in the rumen and increases the cattle's appetite to consume the cheatgrass,” he says. “When we entered the study, we didn't know what condition the cows were going to be in after 30 to 60 days of a cheatgrass diet. We didn't want them to lose weight. We found that the cows either maintained their weight or gained weight.”
“Fall grazing is more logical because the cows consume it all the way including the litter, thus helping reduce cheatgrass the following years,” adds Perryman. “It's also easier because you know where the cheatgrass is and how much of it there is. You can decide when you want to graze it, you can measure how much forage there is, which then allows you to determine how many cows you can put there and for how long. In our research, we couldn't find a downside to fall grazing. The results were all positive.”
Cheatgrass is a common name given to downy brome by Western farmers who thought they had been given impure seed when the grass started spreading into their wheat fields. It’s an invasive species that began spreading quickly during the late 19th and early 20th centuries, displacing native plants. It can produce more than 10,000 plants per square yard and is highly flammable. Cheatgrass is currently the dominant species on more than 100 million acres of land in the intermountain West.