By Taylor Dill | Ohio State University Extension
Livestock producers have many annual forage options to supplement perennial forage production throughout the year. Producers can tailor their forage choice to best serve their nutrient needs.
In the late spring and summer, annual warm-season grasses, in a monoculture or a mixture, can supplement your production. If you are looking at terminating a hayfield after a first cutting because of a thinning stand or winter damage or want to double-crop after a winter cereal grain a summer annual can be planted.
Interseeding in late spring into a winter wheat stand toward the end of the season before it is harvested for grain is another option for a summer annual. Summer grasses that are high biomass producers are sudangrass, sorghum and sudangrass hybrids, and millet varieties.
All of these grasses can be planted after the soil reaches 60 degrees Fahrenheit and planted throughout the summer, after small grain harvest. Sudangrasses, and sorghum and sudangrass mixtures are fast-growing, high biomass producing forage and cover crop options.
Prussic acid
The main downside of these grasses is that they produce prussic acid, which is hydrogen cyanide. This compound is highest in young plants, and cutting or graze these grasses after the plant height reaches at least 18-20 inches tall is essential. Cutting at this height can provide two to three cuttings in a summer.
Prussic acid is generally lost during the curing process, so hay and silage are rarely toxic, even if the cut originally was. However, do not leave green chop out in a wagon overnight, the heat that gathers will release prussic acid and increase the risk of toxicity in the feed.
Seeding and cutting
These grasses should be seeded at a 1-inch seeding depth. If using a drill, the seeding rate should be 25-35 pounds per acre or 20-30 pounds per acre while broadcasting. Keeping the seeding rate high creates slimmer stems, which improves dry-down.
The nutrient content available during the season varies based on the growth stage. However, when cutting for hay, we recommend cutting at early vegetative stages, which would have a crude protein of 16.8%. This would occur about 45 days after planting for a first cutting and 25 days for a second cutting, obtaining between 3-6 tons per acre.
Nutrients
These summer grass options provide outstanding crude protein and yield benefits. Pearl millet and Japanese millet are similar forages but have some striking differences. Pearl millet will out yield Japanese millet by 4-6 tons per acre to 3-5 tons per acre; however, Japanese millet has a higher crude protein content of 17.2% to 11.5%.
There is also some evidence that shows that Pearl millet may cause butterfat depression, if you are using this forage, keep an eye on your butterfat levels.
Plant millet species between June 1 and July 15 at a depth between 0.5 inches and 1 inch at a seeding rate of 25-30 pounds per acre. These are to be harvested at boot stage, leaving 6-10 inches of stubble for regrowth.
With millets and sorghum and sudangrass mixtures, nitrate levels can become an issue in times of drought and nitrate does not leave after the hay is cut or cured.
Teff
Lastly, Teff is a newer warm-season annual being utilized in Ohio for forage production, traditionally raised for grain and moved over into a forage here in the United States from Africa. Teff is a low input and high-quality forage, averaging a protein between 12-17% and a yield of 4-7 tons per acre.
Teff does not have a high nitrogen requirement (50-70 pounds per acre), but the main management stress is weed control during the young vegetative stages. There is a lack of labeled herbicides and Teff does not get competitive until later stages, therefore, pre-plant weed control is imperative.
Many cuttings can be taken off of Teff if it is planted in the late spring, after the last frost date. Each cutting should precede heading. Teff should be seeded at 7-10 pounds per acre for coated seed on a very firm seedbed at a 1/4-inch depth maximum. This forage has potential on many farms looking at diversifying and can be especially profitable as a rotation between alfalfa crops.
Annual summer grasses have a lot of diversity and potential to improve farm efficiency and productivity, covering acreage all year round while providing improved soil health.
(Taylor Dill is an agriculture and natural resources educator for Ohio State University Extension in Darke County.)
