Melissa Beck for Progressive Forage
Mob grazing is the rage, but what does that even mean? Well, it depends on who you ask. There is a lot of confusion over the term “mob grazing.” Most often, producers who use the term are really talking about management-intensive grazing.
But even among practitioners of mob grazing, there is a difference of opinion about what the term means, how it’s done, the benefits and even the negatives of the strategy.
What is mob grazing?
Jim Gerrish, an independent grazing lands consultant, says, “Mob grazing is a term I actually don’t use. There is so much variation in how people are interpreting and applying the term. However, from my perspective, if somebody is actually using mob grazing, I have two basic criteria: There is more than one class of livestock in their herd, and they’re moving more than once a day.”
Part of the misunderstanding about mob grazing is that several terms are used interchangeably for mob grazing. Conversely, the term mob grazing is often misapplied to various intensive grazing systems.
Greg Judy, owner of Green Pastures Farm in Missouri and author of several books about grazing, believes increasing stocking density makes grazing behavior and manure and urine distribution more efficient.
James R. Russell, professor emeritus, Iowa State University, conducted four different trials with mob grazing using as much as 500,000 pounds of animals per acre. He says, “Rather than being a season-long system, I believe that mob grazing should be thought of as a pasture management tool used for strategic purposes such as:
- Increasing the proportion of legume species in cool-season grass pastures;
- Improving wildlife habitat or forage quality in previous CRP land;
- Initiating stockpiling of forage for winter grazing.”
Russell added, “Mob grazing is actually most effective at changing the botanical composition of pastures under wet conditions depending on the soil seed bank.”
The biggest misconception among producers is: They think they will be able to increase stocking rate. However, according to Russell, it takes a such a long time for plants to recover that they may actually need more land and a lower stocking rate during the first two or three years of mob grazing.
The stocking density is largely determined by the amount of standing forage available.
Despite claims that mob grazing increases soil organic matter, in Russell’s studies there was no impact on organic matter.
There are misconceptions among some producers about how organic matter is accumulated and how much effect grazing strategies can have on organic matter content. “Soil organic matter is much more than just trampled plant residues.
It is primarily the result of micro-organisms and aggregates associated with plant roots and their exudates. Every soil is different and has different capacities to hold organic matter. Situations with perennial vegetation such as grassland have better organic matter capacities than cultivated land such as cropland,” Russell says.
Research shows moderate stocking rates increase organic matter. Pastures managed poorly will have lower soil organic matter than pastures grazed at a moderate stocking rate.
Judy says, “Trampled plants are the whole fertility cycle of our farms. Just because we did not graze them does not mean this forage was wasted. Trampled ungrazed plants feed the litter bank that covers our entire farm and keep soils insulated from the sun, preserve moisture and give the soil microbes a constant supply of food.”
“We manage 16 farms and have been able to double our stocking rates due to the increased fertility from mob grazing over the last 10 years. By doubling the number of animals that we are now grazing, it has cut our input costs in half,” Judy says.
In terms of benefits to the soil and forage, Gerrish says, “Done right, mob grazing absolutely can benefit the soil and forage base; done improperly, it’s worse than long-term continuous grazing because you can degrade a piece of land so rapidly. So the question becomes: What is ‘doing it right?’”
Making it your own
Gerrish says, “In term of the stock density, we move once a day here and generally will be somewhere between 50,000 and 90,000 pounds (per acre) live weight-basis stock density. We have one location where I move two or three times a day because we are working on weed control. But since we only have one class of livestock there, I’m not going to call it mob grazing.”
“Doing it right is leaving an appropriate amount of residual behind during the growing season. I have a hard time wanting to utilize more than 50 percent of the standing forage in a single grazing event. Out here, under irrigation we push it to 60 percent because we know we’re going to get water on it within three days of any grazing event. So we push it a little harder,” Gerrish says.
Chase and Krystal Groves, owners of Rocking CK Farms in Arkansas, run 80 cows and 250 to 350 forage-developed bulls as well as a custom grazing operation. They utilize rotational and strip grazing. They rotate at least every seven days and are working toward a system of short-duration grazing where the stock are moved multiple times a day.
Groves utilizes a type of mob grazing, not as a continuous practice but to manage forage in targeted situations. In the fall, they mob graze warm-season forages to remove excess, then no-till cool-season crops for winter grazing.
“Our goal is to mob graze cover crops and utilize land before planting cash crops,” Groves says.
Gerrish says, “The preferred term is ‘management-intensive grazing,’ emphasizing that the intensification is on the management, not on the grazing. That’s the important piece. Mob grazing, however it is described, is a subset under the umbrella of management-intensive grazing.
It’s a form of grazing that requires a much higher level of management than just turning them out in the spring and rounding up in the fall.”
“Back in the ’80s, when the commonly used term was ‘intensive grazing management,’ people picked up on the ‘intensive grazing’ but missed the ‘management.’ They put up fence and move the cattle around, but they’re coming back to the pastures way too quickly,” Gerrish says.
Regardless of what you call it, successful grazing management has the essential components of leaving a proper residual of standing forage and an appropriate recovery period between grazing events.
According to Gerrish, the rest period is key to success regardless of what grazing system you’re utilizing. “Out in some of the desert rangelands, the recovery period has to be longer than 12 months. They might have cattle on those for three months and then off for 15 months.
In Missouri, if I grazed it more severely than 50 percent, I had disappointing recovery and would have to allow for a longer recovery period. In any kind of grazing management, the recovery time is critical.”
Gerrish says, “The rest period depends on growing conditions. Out in Idaho, grazing irrigated pastures, we make it rain every three days, so our rest period is 35 to 50 days with the 50 coming later in the growing season, when the days are getting shorter and we get less sunshine. It is a significant amount of rest for those pastures.”
Judy says, “The downside is that mob grazing requires management and education. You simply cannot go out and move cows without knowing what you are doing.”
“This is not a system that you can use a calendar to move your herd with. You must be very flexible and observant to what is going on in your surroundings every day,” Judy says.
If animal performance is the goal, graziers use much lower animal density and have more success with well-managed rotational grazing than mob grazing.
Gerrish says, “There are a lot of people who have started mob grazing and have had disappointing animal performance, and I think that is mostly attributable to not leaving enough residual because they don’t want to waste any grass. The key to prioritizing animal performance is to never be afraid to ‘waste grass.’”
Whatever it’s called, all management-intensive grazing is a strategic approach and requires
close monitoring, flexibility, planning and is a balancing act between animal performance and forage utilization.