Don T. Winch

Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)




The use of summer annual forage crops to supplement cool season perennial forages for grazing has become popular in the mid-western area of the United States. Sudangrass (Sorghum sudanese (Piper) Stapf.) is one of the most important sources of annual summer feed in this area. With the advent of more vigorous and well adapted varieties and hybrids the use of sundangrass has greatly increased. It produces high yields of good quality forage in a short period of time. Sudangrass makes its best growth during mid-summer when most pasture species are dormant or semi-dormant (14). It will tolerate long periods of drought and make rapid growth when moisture becomes available. Because of its annual nature it makes an excellent emergency forage when perennial species have failed. Research work on the management of sudangrass has been limited. Questions still exist as to how this crop should be grazed and what stocking rates should be used. The approximate rate of gain and yield of animal products that could be expected were not well established. The hydroncyanic acid content of new sudan hybrids under grazing management is not well known. Other questions concerning the production and grazing management of sudangrass pertained to: (1) response to nitrogen fertilizer; (2) the height to which sudan should be grazed; and (3) the yield of new hybrids in comparison with a standard variety. Two experiments were designed to provide information concerning the use of sudangrass for beef production. One was a non-grazing experiment, the objectives of which were to determine the dry matter yield, hydroncyanic acid content1, and nitrate content of three sudangrass types2 as influenced by three cutting heights and three fertility levels. The other was a grazing experiment. The objectives of this study were: (1) to determine the effect of three grazing systems on animal performance; (2) to determine the effect of three grazing systems on animal performance; (2) to observe the influence of row width on yield and the amount of trampling and waste during grazing; and (3) to draw a relationship between the cutting treatments of the non-grazing experiment and the grazing systems of the grazing experiment.

Library of Congress Subject Headings

Sudan Grass




South Dakota State University