Former Extension Educator, Local Food Systems and Small Farms
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Monday, February 1, 2016
Mob grazing, sounds a bit crazy but it just might be the answer to your pasture problems. Short duration, high-intensity grazing in small areas paired with multiple daily moves (and some focused oversight of animal performance) and you get mob grazing. A grazing system that improves forage, improves soil health, allows producers to increase stocking rate and improves animal health.
How does it work? Think of how wild horses, buffalo and bison moved about the western rangelands. They didn’t stay in one area, they freely grazed and moved on from lands that had been soiled by manure. They often didn’t return for months or even years, allowing the land to rest and recover. When pastures are allowed to rest, forage production improves. Mob grazers do just that, dividing pastures into smaller paddocks and allowing each paddock to rest for longer periods of time than traditional rotational grazing programs before returning to it.
To successfully use mob grazing in your operation, you need to determine an optimal stocking density (animal pounds per acre). We will talk about cows for the most part, but the concept can successfully be used in other species as well. For instance, 100, 1,000-lb. cows would be 100,000 lbs. On a half-acre, 100 cows would be 200,000 lbs., while 100 cows on 10 acres would be 10,000 lbs. The higher the density, with shorter grazing periods, the more uniform the urine/manure distribution will be. You’re fertilizing the entire piece – dumping more nitrogen back on that pasture. For instance, 100,000 lbs. of animals typically leave 50-55 lbs. of readily available nitrogen on the ground as urine. The higher the stock density, the more uniformly nitrogen is distributed large groups of cows confined in small areas become incredibly aggressive grazers. The key is to utilize smaller areas of pasture and multiple daily moves to get the most out of your forage.
Some producers are able to extend grazing by one to five months. Many have gone to year-round grazing, which many people say you can’t do in most areas. Stockpiling grass and grazing through winter help producers accomplish grazing longer, reducing or even eliminating the need for hay. Mob grazing also leads to greater plant diversity which is beneficial for nutritional needs of cattle and other livestock, as well as the health of the land. More diversity in plant life leads to a more resilient pasture. A mix of cool and warm-season grasses and broadleaf plants help pasture to withstand drought. Mob grazers are likely to find new plants each year, some have counted up to 100 different species in their pastures. Even with such plant diversity, livestock can still be picky eaters. They will have plants they favor over others which means some plants will always be grazed heavier and some will never get touched. An extended recovery period allows the heavily grazed plants to recover instead of get trampled out.
Mob grazing is hailed as a tool to quickly heal and build up worn-out soils. Traditionally grazed pasture can take a 100 years to renew the soil, but with mob grazing those changes can start to be seen in a few years. Mob grazers have seen soil organic matter increase up to 6% or better in just a few years. The heavy trampling of a high-stocking rate helps feed the soil biology. Leaving forage builds up organic matter cows can trample in the winter during the dormant season.
The livestock see benefits too. Fly burden is greatly reduced or almost gone. Horn flies, which plague many cow herds in the summer months, breed in fresh cow manure and hatch a new generation two weeks later. By the time the next generation hatches, the cattle or other livestock have moved on, leaving the fly population with no food source so they die off. Mob grazing also reduces internal parasites in much the same way. Cattle or other livestock aren’t constantly eating where they defecate, so they aren’t picking up worms. The worm larvae may move onto nearby foliage but if plants aren’t eaten short, the livestock won’t ingest worms breaking the parasite lifecycle.
Mob grazing won’t fit every operation. It takes extra labor and time to do it right. But if you have the tools to utilize it, even on a small portion of your land, you can do your pasture and livestock a world of good.