ARS | Publication request: Sward Structures and Quality Differences among Temperate Grasses

Submitted to: American Forage and Grassland Council Conference Proceedings
Publication Type: Proceedings/Symposium
Publication Acceptance Date: May 11, 2005
Publication Date: June 14, 2005
Citation: Brink, G.B., Casler, M.D. 2005. Sward structure and quality differences among temperate grasses. In: Proceedings of the American Forage and Grassland Council. June 12-14, 2005, Bloomington, IL. 2005 CDROM.

Technical Abstract: Grass sward structure influences intake by grazing animals. Our objective was to determine dry matter (DM) and quality distribution within swards of diverse temperate grasses. When each grass reached approximately 10 in height during the spring, summer, and fall, the sward was harvested by layers: 8 to 10, 6 to 8, and 4 to 6 in. Ranking for sward DM density among the grasses was influenced by the sampling period. Grasses that typically exhibit vigorous early spring growth, such as timothy, smooth bromegrass, and quackgrass, produced more DM in the upper and middle portions of the canopy than orchardgrass, perennial ryegrass, and meadow fescue, while the opposite occurred in the summer. From the top to the bottom of the canopy, mean crude protein and neutral detergent fiber digestibility (NDFD) of all grasses decreased 5% and 3%, respectively, and neutral detergent fiber increased 10%. In perennial ryegrass, timothy, and meadow fescue, however, NDFD was similar throughout the canopy. The results suggest that depending on the season, grasses require different management to maximize utilization, and that forage quality differences between canopy layers permits more complete utilization of some grasses than others without forcing the animal to consume poorer quality forage.