Highlighted Research: How the Growing Season Influences Range Forage Quality

Alex Orozco  Mitch Stephenson   

By Alex Orozco, UNL Research Technician and UNL M.S. Student, and Mitch Stephenson, UNL Range Management Specialist

Understanding how forage quality of different plant species changes during the growing season can help improve grazing management and livestock production. Having a clear understanding of the dominant plant species found in our pastures can improve coordination of nutrients available through rangeland species throughout growing season and livestock nutritional needs can improve the livestock management (animal performance, cost, etc.).

In 2020, a study conducted at the Gudmundsen Sandhills Laboratory (GSL) in Whitman, NE analyzed forage quality change on current-year growth of individual plant species on Sandhills upland range during the growing season (May-August). Every 7 to 14 days, forage samples of a cool-season grass (needle grasses), a warm-season grass (little bluestem), and a forb (stiff sunflower) were collected and analyzed for crude protein (CP) and Total Digestible Nutrients (TDN). Figure 1 below shows as the grazing season progressed, forage quality (CP and TDN) decreased for needle grasses, little bluestem, and stiff sunflower regardless of the functional group. Figures 2 through 4 shows the growing season of needle grasses, little bluestem, and stiff sunflower, respectively. Therefore, a better understanding of the forage species found in our pasture can help us better understand the forage quality of our range throughout the grazing season.

Crude Protein        TDN

Figure 1. Forage Quality (CP and TDN) of needle grasses, little bluestem, and stiff sunflower at Gudmundsen Sandhills Laboratory

Needle grass

Figure 2. Growning Season of Needle Grasses at Gudmundsen Sandhills Laboratory.

Little Bluestem

Figure 3. Growing Season of Little Bluestem at Gudmundsen Sandhills Laboratory.

Stiff Sunflower

Figure 4. Growing season of the Stiff Sunflower at Gudmundsen Sandhills Laboratory.