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Management

Annual forages provide alternative grazing

Producers who are short on grass or want to rest their pastures may want to consider planting annual forages. According to University of Nebraska Range and Forage Specialist Jerry Volesky, annuals can be a good fit with a grazing program, if proper planning is done ahead of time.

Many annuals can be used for grazing, Volesky said. Some of the more common cool season annuals are oats, spring triticale, spring barley, field peas, Italian or annual ryegrass, turnips, radishes, winter wheat and rye. Warm-season annuals like millet, S-S hybrids, sorghum, sudangrass, crabgrass, teff and corn can also provide grazing for livestock, he added. 

“Grazing is not as efficient as haying these annuals,” Volesky cautioned producers. 

Grazing interrupts plant growth more than haying because haying takes place more toward the end of the plant’s growing cycle, he explained. 

“Grazing interrupts plant growth, and may reduce the potential of future growth,” he added. 

As an example, Volesky said if a cow grazes off the growth point of an oat plant, any future growth of the tiller of that plant will be lost. Losses can also occur from trampling. 

Planning ahead

It is important to plan ahead when additional grazing may be needed, the range specialist continued. The plants will need adequate time to grow to the appropriate stage or height before they are grazed. 

Volesky encouraged producers to consider planting different types of annuals that can be rotationally grazed and to stagger the planting dates of warm season annuals to prevent them from growing too rapidly before they can be grazed. 

“Producers will want to start grazing these annuals at a younger stage of growth or at a shorter height,” he explained. “Animals can be added as needed depending upon the growth of the forage.” 

Producers should have a backup pasture in case plants are consumed quicker than expected, or the stocking rate doesn’t work out as planned, he said. 

“It is important to have something to fall back on,” added Volesky. 

Producers should start grazing annuals at the appropriate stage of growth or height. For small, cool season grains that are spring-planted, they shouldn’t be grazed before they reach six to eight inches tall, which should be around May 15-25. 

Late-planted small grains should be allowed more growth before they are grazed. Volesky recommended Oct.1. 

For warm season annuals, like sudangrass and pearl millet, the plants should be 15 to 20 inches tall and 18 to 24 inches tall for S-S hybrids. 

Grazing rotations

Simple grazing rotations can be beneficial, Volesky said. 

In an example using the warm-season annual, sudangrass, with staggered seeding, Volesky showed the annual in Field A was seeded on June 1 and grazed when it reached 15 to 20 inches tall for seven to 10 days. The cattle were then moved to Field B, which was seeded on June 12 and grazed when it reached 15 to 20 inches tall for seven to 10 days. The cattle then moved to field C, which was seeded on June 26 and also grazed for seven to 10 days when it reached 15 to 20 inches tall. The cattle then moved back to Field A, and the cycle was repeated. 

Combinations

“Growing these annuals in combination can also work out well,” Volesky said. 

He showed an example of planting rye the previous fall and grazing it in April and May. Sorghum sudangrass is then planted the first of June and grazed from July through September. 

Volesky cautioned producers that they will need to have native pasture or some other type of feed for livestock during the month of June, while the sorghum sudangrass is growing. 

Another alternative is planting oats in late March and grazing in late May and June. Sorghum sudangrass is then planted July 1 and grazed in August and September.

Stocking rates

Volesky said there is always a lot of concern from producers regarding what is a proper stocking rate for annuals. Volesky said he likes to use an animal unit concept, based on one animal unit (AU) is equivalent to a 1,000 pound animal, and one AUM (animal unit month) is equivalent to 780 pounds of forage. This is based on 30 days in a month where 26 pounds of forage is consumed per day. 

A cow/calf pair is considered 1.5 AU, and a weaned calf (500 pounds) is considered 0.5 AU. 

Volesky said when working with annuals, it is important to consider grazing efficiency. 

“A rule of thumb is 1.3 AUM per ton of potential forage,” he said, assuming 50 percent grazing efficiency. 

Fall and winter grazing options

Volesky said producers can consider leaving some of the warm-season annuals growth and stockpiling it by either leaving it standing in the field or windrow grazing. 

Cool-season annuals, like oats and turnips, can be grazed after freeze-down or also by windrow grazing, he added. Volesky said he has done some work utilizing windrow grazing during the summer. His research was with winter rye and showed the importance of harvesting the crop at the optimum maturity so the animals will utilize it efficiently in the windrows, he said.

Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.