Chemical Composition, Grazing Value and Vegetative Changes of Herbage in a Typical Plains Pasture

Beginning in May, 1939, samples of buffalo grass, blue grama and Russian thistles were taken bi-monthly from fenced square-meter plots in a 32-acreterraced pasture for chemical composition study. Density readings were taken spring and fall from unfenced plots. Yearling Herefords gracing the pasture were weighed every fifteen days during the grazing season. Sheep were used to utilize weeds and surplus grass in 1940 and 1942 respectively. Moisture, crude protein, carotene and phosphorus were high in the three herbages during the early stages of growth but decreased rapidly as the plants approached maturity, usually during July. Buffalo grass proved to be superior to blue grama for winter pasture, and its chemical composition was affected less by clipping. Yearling Herefords grazing the pasture for an average of 129 days for 4 seasons made an average daily gain of 1.01 pounds and produced a yearly average of 29.3 pounds of beef per acre. The average daily gain for June was 1.47 pounds compared to .53 pound for August. Gains were high when the protein and carotene content of the herbage was high in June and correspondingly low in August. Sheep were used early in the seasons of 1940 and 1942 to utilize more completely weeds and surplus grass. The use of sheep added materially to the gracing capacity of the pasture. There was a great increase in the density of buffalo grass above the terrace ridges. In the dry season of 1940 there was a considerable decrease in density of grass on unflooded areas below the terraces. Although Russian thistles were prominent in dry seasons, the grasses tended to crowd them out during the wet seasons of 1941 and 1942.