You probably don't want to think about summer forages and grazing with all of the talk about dangerous wind chills, the polar vortex, and lots of snow. However, you should be because spring and summer are just around the corner.
This is a good time to study new developments in forage varieties and pasture grass species.
The 2014 seed and forage guides are out, and varietal test results have been published. If seed is not yet ordered for frost seeding, planned renovation, new pasture development, or for summer annuals, it should be done before supplies are reduced. Key points in pasture and forage development include choice of adapted varieties and species that will persist for several years and adding legumes to provide nitrogen. Some research has recommended diversifying pasture and forage systems to include warm season species in the summer and annual cool season species in the fall. Why should summer annuals be considered by all dairy producers? They are very drought tolerant and can fill a gap in feed when other species experience the "summer slump". They are great emergency forages during dry weather and are multipurpose, so you can be use them for grazing, silage, or for baling.
During the summer of 2013, we planted two summer annuals for grazing for the first time at the University of Minnesota West-Central Research and Outreach Center dairy in Morris. BMR sorghum-sudangrass and teff grass were planted to create a more uniform and extended forage supply. These grasses were seeded with a drill on May 28, 2013, but because of the late spring, this was about 2 weeks later than what we had planned.
BMR sorghum-sudangrass has increased in popularity due to the BMR gene and increased NDF digestibility (5 to 10% higher than regular sorghum-sudangrass). The plants have thick stems and are very leafy. Sorghum-sudangrass has moderate regrowth potential, but you should not graze or cut for forage until the plants are at least 18 inches tall to reduce prussic acid concentration. The ideal height for forage is 18 to 36 inches tall. When grazing sorghum-sudangrass, animals should be moved so they leave 6 to 8 inches of stubble, but they might waste 20 to 30% of the forage through grazing. Lastly, sorghums and sudangrasses are luxury consumers of potassium, so they should not be used for dry cow forages. For seeding rate, we seeded our fields and pastures at 20 pounds per acre.
Teff grass is native to Northern Africa. Teff is drought tolerant and can be seeded into many different soil types. With this grass, you will have high yield with competitive forage quality, and will have rapid growth for 9 to 12 weeks. The seed is very, very small, and we seeded our pastures at 8 pounds per acre.