In mob grazing, a large number of animals are restricted to a small area, either eating or trampling all the plants before being moved to new grass after a few hours. It usually starts later than conventional rotational grazing, when pastures have more growth, and is followed by a longer recovery period. So pastures typically are mob-grazed just once or twice per season
Mob grazing has increased the carrying capacity of Bruce Anderson’s pastures, but he hasn’t seen any of the other benefits frequently claimed for the method also known as ultra-high stock-density grazing.
“I think it has a role and a place where it can be very effective,” says Anderson, University of Nebraska Extension forage specialist. “But also there are situations when it may not be most suitable.”
His pastures are on clay-loam soils, and when it rains, the cattle quickly turn them into a “muddy mess,” he says. The muddiness is exacerbated in areas where the cattle trail back over grazed areas to get water.
“There gets to be way more damage than I’d like to see for the long-term health of the stand,” he says. “You end up having a loss in regrowth and stand density in subsequent growth periods.”
Anderson began mob grazing his herd of about 40 cow-calf pairs two seasons ago, thanks mostly to Terry Gompert, a Knox County, NE, Extension educator. Gompert, who passed away this past March, was a leading mob-grazing proponent.
“His enthusiasm encouraged me to give it a try, both to see if I could improve the output from my grazing as well as to give me experience and knowledge to talk to other people about it,” says Anderson.
“It’s probably the most controversial and discussed grazing topic that’s out there right now,” he adds.
In mob grazing, a large number of animals are restricted to a small area, either eating or trampling all the plants before being moved to new grass after a few hours. It usually starts later than conventional rotational grazing, when pastures have more growth, and is followed by a longer recovery period. So pastures typically are mob-grazed just once or twice per season.
Some mob graziers stock up to a million pounds of cattle per acre, but Anderson peaked at about half that amount.
“The higher you go the more often you have to give them a fresh patch during the day,” he says. “You have to come up with some comfortable level where you’re able to get the animal impact you’re seeking from the high-intensity grazing vs. the amount of labor and logistics challenges that you’re dealing with.”
He has moved his herd up to four times a day, but because of the labor requirement prefers to do it two or three times. He does one or two of the moves, and his wife, Diane, does the others.
The 70 acres of pasture include a diverse mixture of cool-season species, mostly bromegrass, bluegrass, orchardgrass, alfalfa and clover, plus 12 acres of bluestem, indiangrass and other warm-season grasses. So far, he’s most satisfied with mob grazing on the warm-season species, but that may be because he hasn’t had mud problems on that pasture.
“When it’s been dry on the cool-season portion, things have gone very, very well,” he says.
His calves gain about 2 lbs/day, the same as when he practiced conventional rotational grazing. They selectively graze higher-quality forages in the pastures while their mothers mostly eat the lower-quality material, he says.
Better grass utilization, faster regrowth, more plant diversity and enhanced nutrient recycling are among the advantages often reported by mob graziers. Anderson’s grass utilization has improved, increasing the productivity of his pastures by about 20%. He spends more time with his cattle now, too, so he’s able to catch health and other problems earlier.
“Any intensification that puts you out there more frequently is going to give you a chance to take care of the animal husbandry part of things more effectively,” he says.
But none of the other benefits have materialized.
“I think there are some legitimate questions about some of the responses that have been claimed,” he says. “They certainly won’t happen overnight and probably will take several seasons before changes become apparent.”
He tells interested graziers to weigh expected benefits against the higher cost of labor and other inputs, mostly fencing and water distribution, then try it on a few acres. But don’t ease into high stocking rates.
“If you’re going to seek the benefits of ultra-high stock density, you need to go to ultra-high stock density. But don’t do it all year.”
Pastures with excess spring growth are good places to experiment.
“Start grazing in May the way you might normally,” he advises. “If grasses start to get away from you in a certain area, that’s the more manageable area to give high-intensity grazing a test. If you do it where the grass is only 8-10” tall, you’ll be moving 12 times a day.
“It might take some creativity to figure out the water and fencing,” he says. “But when conditions are dry it doesn’t hurt to allow the animals to walk back for a day or two across areas that have been intensively grazed to get their water. You don’t have to have water in each little piece that you graze.”