Developing a grazing plan can lead to better pasture managementWritten by Gayle Smith
With summer grazing season approaching, it may be time to develop a grazing plan. According to Nebraska Extension Educator Troy Walz, the elements of good grazing management are stocking rate, timing of grazing or season of use, distribution and kind or class of livestock.
“Producers should develop a grazing strategy,” Walz said.
Factors like livestock management, production objectives, pasture objectives, plant resources and season of use can all help ranchers develop a good grazing management strategy, he explained.
Capacity and rate
“Grazing capacity is the total number of animals which may be sustained on a given area based on the total amount of forage available,” Walz said. “The stocking rate is the animal unit demand per unit area over a period of time. It is a management decision.”
Both are important considerations for maintaining an equilibrium between what is best for the cattle and the grass they graze.
The biggest influence is stocking rate, Walz said.
“It impacts how well the plant can recover from grazing during the growing season, as well as future forage production, the quality of available forage, animal performance and long-term change in species composition,” he said.
Stocking rate can be determined by animal units (AU), which is based on the standard that a 1,000-pound animal consumes 26 pounds of air-dry forage a day.
“The animal unit concept allows for expressing forage supply and demand using a common unit of measure,” Walz explained.
Walz said the amount of forage an animal consumes in a month is referred to as an AUM, or animal unit month. The standard is 780 pounds of air-dry forage for a 1,000-pound animal.
Using those figures, producers can adjust for larger or smaller animal size, or determine animal unit days or year.
Walz shared with producers some ways to determine available forage supply. Table values, based on ecological or range sites and species composition, are available.
Producers can also use data like hay yields, visual estimates or clip samples. They may also rely on records, observations and experience. Producers can also use vegetative zones to determine stocking rate.
“Grazing management is simply the manipulation of grazing animals to accomplish desired results in terms of animal, plant, land and/or economic responses,” Walz said.
Simply put, Walz said producers need to develop a scheme where they take half and leave half, while taking into account leaving behind forage for wildlife and trampling that will occur during grazing.
“The proportion of the total standing crop commonly allocated to different functions to maintain healthy rangeland under continuous grazing is harvest efficiency,” Walz said.
In the take half, leave half scenario, 50 percent of the plant is allocated to plant vigor or leaving half while 25 percent is allocated to livestock consumption, and another 25 percent is allocated to trampling, wildlife and insects.
Harvest efficiency is typically 25 percent.
Developing a system
Producers can make the most of the grass they have by developing a grazing system.
“The grazing system affects grazing distribution in a pasture,” he said. “Grazing distribution can be improved by fence placement and the location of water sources.”
Ultimately, improved grazing distribution will increase grazing efficiency, he continued.
Slope can also impact the amount of forage grazed. Walz shared a diagram indicating that, with a 10 percent slope, cattle still utilized 100 percent of the usable forage, but at 30 percent slope, the cattle only utilized 70 percent.
If they had to climb a 60 percent slope, the amount of usable forage grazed declined to 40 percent.
Producers can use various grazing systems to manipulate grazing distribution and control timing of grazing or season of use, Walz said.
The easiest system to manage is season-long continuous grazing.
“Producers only have to decide how many head to put in a pasture for how long,” he said.
Typically, the cattle graze in the same pasture from May through October. Although the cattle performance can be very good with the proper stocking rate, there is a risk of damage in preferred areas and grazing distribution may be less than desirable.
The cattle will keep grazing vegetative growth, which can be hard on plants but good for the cattle. In preferred areas, the cattle may cause blowouts and damage preferred grazing areas. Walz said grazing distribution may be poorer with this system because, depending upon water placement, cattle may not graze in certain areas, but that could be good for wildlife.
In a rest-rotation system, one pasture in the system is rested for a full year, which increases plant vigor for the rested pasture.
Walz said the stocking rate is proportionally higher in the other pastures, which may result in better grazing distribution.
Each pasture is grazed once a year in a deferred grazing system. Walz said the benefits are increased vigor in late-spring and early summer deferred pastures.
“It is well-suited for range grasses that benefit from seasonal rotational grazing. Grazing distribution will be good,” he explained.
Within this system, Walz said every pasture is grazed a different time of the year, which allows for more improvement in the vigor of grasses.
Producers with plenty of labor available could consider an intensively managed, short-duration grazing system.
In this system, each pasture is grazed one or more times during the year. Although it has excellent grazing distribution, inputs for fence and water may be higher, Walz said.
In an intensive system, producers will have more flexibility for when they use a pasture, and how they stock it. They may also be able to graze some pastures more often than others.