In 1989, the CGREC initiated a grazing-intensity research project that is ongoing. The objectives of the project are to determine the effect of grazing intensity on livestock performance and profitability and the sustainability of forage production. Five treatments are included in the study: no grazing, light, moderate, heavy, and extreme grazing. Each treatment is replicated three times in pastures of about 30 acres each except the no-grazing treatment, which consists of six 0.3-acre exclosures placed on both overflow and silty range sites. Livestock are not rotated between pastures and each pasture receives the same treatment each year. Our goal is to stock the pastures each year so when the cattle are removed in the fall, 65%, 50%, 35%, and 20% of the forage produced in an average year remains on the light, moderate, heavy, and extreme treatments, respectively. For these pastures, that means 2026, 1618, 933, and 480 lbs./ac. of forage remaining on the light, moderate, heavy, and extreme pastures, respectively. Table 1 presents the stocking history of the study and Figure 1 shows how much forage remained at the end of the grazing season each year.

To attain the desired grazing intensities, adjustments in stocking pressure are made each year based on information from previous years. Changes in the vegetation are determined by monitoring permanent plots located on silty and overflow range sites in each pasture and on the six exclosures. Table 2 lists the average production on these range sites during each year of the study and the total precipitation for the year

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