Tailoring grazing programs to season optimizes animal, plant healthWritten by Emilee Gibb
As livestock producers are planning their grazing systems for the year, University of Wyoming State Beef Extension Specialist Steve Paisley explains that many factors need to be considered for each season to optimize both plant and animal health.
The intensity that pastures are grazed and the length of time that animals are left in the pasture is partially dependent on the time of year, says Paisley.
He explains that typical springtime grazing programs rapidly move animals through small allotments.
“Usually, if we’re going to graze in the spring, we graze pretty moderate to heavy, so we try and graze smaller or more concentrated areas more heavily in the spring because that’s when the rapid growth hits,” Paisley says.
Alternatively, summer and fall grazing is normally done at a slower pace.
“Forage growth slows down, and we move cattle a little slower in the summer months,” continues Paisley.
Paisley explains that while every intensive grazing program is different, there are general recommendations for how long to allow animals to graze.
“If we’re in some kind of rapid movement or intensive grazing type of program, we’ll graze anywhere from three to seven days and then allow a minimum of 21 days recovery after that. That’s kind of a rule of thumb but every pasture size and number of cattle varies,” he says.
From the perspective of plant health, intensive grazing in the spring is the most harmful, says Paisley.
“From the plant’s standpoint, probably the most detrimental time to graze grass is when they’re using up their root reserves to have a rapid growth phase,” he continues.
Repeatedly grazing the same pastures in the spring without a deferment period negatively impacts plant health. Alternatively, Paisley explains that rotational grazing programs aim to vary the time of year that pastures are utilized.
“If we graze the same location heavily during the same spring period every year, we’re going to negatively impact those grasses. The idea is we have the ability from a rotation standpoint to never graze the same pastures at the same time every year,” says Paisley.
As plants enter dormancy in the fall, intensively grazing the pasture will not have significant impacts on overall plant health.
“If we really want to protect or encourage grasses in a particular pasture, don’t graze it until after it goes dormant because then we’re going to allow it to respond and recover. Then we can graze it when it’s little or no impact on the plants,” he explains.
“If we’re unfamiliar with the pasture, there are resources we can use to estimate and determine how long we should leave animals on a pasture,” says Paisley.
He explains that producers need to estimate total forage production in the pasture, then stock appropriately. Forage production will vary greatly depending on predominant grass types.
“In short-grass prairie, that is primarily buffalo grass and other short grasses, we’re going to stock those with fewer than we would a real rapid growing pasture, like a brome-type pasture. It depends on the location,” says Paisley.
The Natural Resource Conservation Service can be an excellent resource for recommendations on forage production and soil types for general areas around the state, says Paisley.
When determining stocking rates, Paisley explains that producers should estimate that livestock will remove 50 percent of the standing forage before moving to a new area.
“Try to work off of some guidelines to begin with. Know what an animal will eat each day and then try to back-calculate to what that is,” says Paisley.
As producers transition to different pastures for seasonal grazing, multiple other factors influence how heavily animals can be stocked.
Water availability is an important factor to be considered in grazing plans, says Paisley.
“We need to think about if there is enough water, especially if we’re concentrating a lot of animals in a small area,” he explains.
The presence of noxious weeds in pastures, particularly in the spring, should also be noted when deciding when to transition animals to new pastures.
“Other things that we typically think about in the spring time is that’s when we a lot of times will have our potentially noxious weeds, whether it’s lupines, larkspurs, death camas or any of those types of plants,” says Paisley.
He notes that intensive grazing programs can make noxious weeds become an even greater problem.
“Anytime we work with an intensive grazing type of a program, we can force animals to eat plants that they typically don’t eat,” continues Paisley.
Paisley stresses that not every pasture will be suitable for an intensive grazing program.
“We’ll have to look at that when we’re grazing to minimize the impacts of some of the plants that are in that pasture. We may have to wait until late summer or fall to graze it,” concludes Paisley.