Nutritional Value of Summer Forages

As has been documented on this blog, summer grazing in the northern Piedmont of North Carolina can be a challenge.  The forage base in this area is cool season grasses, which go dormant during the summer months.  This makes many folks think about something to use during the summer to provide good nutrition to their horses.  Often, the answer is to use a summer annual grass.  There was an article written last May (Summer Annuals) that describes which summer annuals are recommended for grazing horses and lists some that should not be grazed by horses.  This article will show a bit more of the differences between these recommended annual grasses used for summer grazing.

The grasses that were recommended were Pearl Millet, Crabgrass, and Teff. Note that most of the quality reports are based on cutting these grasses for hay. Let’s look at some test results for these forages.

Pearl Millet – according to researchers at the University of Georgia, protein levels range from 8 to 11%, depending on plant maturity at harvest. The Total Digestible Nutrient (TDN) levels ranged from 52% to 58%, so this can be a pretty good forage during the summer months.  Consider that the 2016 yield data from Tifton Georgia shows an average of 15,500 pounds of dry matter produced, horses should not go hungry using Pearl Millet for their summer grazing.  Pearl Millet does not produce prussic acid, so that should not be a worry in the fall after frost, but be careful and check for nitrates, especially after the plant has fast growth following a drought situation.

Crabgrass is a summer annual that not many people think of for use in grazing, but it is a solid performer during the summer months.  Crabgrass is an annual, and there are two named varieties that have been developed for use in pastures.  One of these is Red River Crabgrass and the other is Quick–N–Big.  There are some others generally classified as “common” crabgrass.  Researchers at the University of Arkansas found protein levels of crabgrass hay that was cut at the early heading stage averaged 14.3%, and the TDN of that hay averaged 59.1%.  Crabgrass cut at the late heading stage still averaged 11% protein and 54.8% TDN. Those numbers translate to some pretty high quality forage to graze horses on during the summer.  The folks at Arkansas found that crabgrass can produce over 8,000 pounds of dry matter per acre.  Crabgrass is usually planted in the fall with small grains, or in April mixed with fertilizer.  Crabgrass seed is small and light and does not flow well in a planter by itself.

Teff – This warm-season annual grass has received a lot of attention in different parts of the country over the last decade.  It also has pretty good protein (9 – 14%) and digestibility (55 - 64% TDN) depending on maturity at harvest/grazing.  The quality data is from New Mexico State University.  Production is between 8,000 and 12,000 pounds of dry matter per acre.  It is a very small seed that requires a good, firm seedbed and good seed placement. It is very easy to plant the seed too deep, so be careful.  Garry Lacefield, Extension Forages Specialist with the University of Kentucky, recommends that Teff not be grazed until the root system is fully established. It is a shallow-rooted grass that can be pulled up by grazing, especially if it is grazed too early.  Still, that’s not bad for a grass originally used as a grain crop in Ethiopia and other countries around the world.