The objective of this study is to determine what stocking rate would result in the greatest economic return to the livestock producer in the long run. The results of this study indicate that for the past 20 years, the optimum stocking rate would have been 1.74 AUM/ton of forage. This is equal to 1,149 lbs. of forage for one animal unit, the equivalent of a 1,000 lb. cow and calf, for one month. Over the past 22 years forage production on our silty range sites has averaged 2,672 lbs./acre. So in a year with average production 0.43 acres of this range site would be enough to supply this amount of forage for a month. However production has varied through the years from being able to supply this amount of forage with 0.32 acres to requiring 0.98 acres. This emphasizes the importance of knowing how productive your pastures are and being able to recognize early in the grazing season if you are in a dry year and will need to find more pasture, or are in a wet year and will be able to lengthen your grazing season and save on hay.

Although 1.74 AUM/ton of forage would have provided the best economic return over the last 20 years, there are a number of reasons to consider a lighter stocking rate. First, the extreme and heavy pastures have been deteriorating in condition through the course of the study and may not be able to support the rates of gain we have seen in the past. Also, both profits and losses are higher at higher stocking rates depending on the difference between spring and fall livestock prices. The producer would experience more years with negative returns at the higher stocking rates.

It appears that the moderate stocking rate may be too conservative if maximizing profit is the objective. In only four out of 20 years, returns would have been higher with a stocking rate less than the moderate rate of 0.69 AUM/ton of forage. In all other years, a higher stocking rate would have resulted in higher returns. For a stocker operation in this area, the optimum stocking rate would fall in the range of 0.69 to 1.74 AUM/ton of forage.

Open heifers were used in this study so these stocking recommendations may not apply to a cow-calf operation because calf gains are largely dependent on the cows’ milk production. Higher stocking rates could reduce the cows’ condition and conception rates and result in higher over-wintering costs to bring the cows back up to condition to calve in the spring. Also, season-long grazing is used in this study; however, we recommend a rotation grazing system. By concentrating cattle on a smaller area for a shorter period of time, more of the grass plants will receive use. Later, when the cattle are moved back into the area, they can graze regrowth on the plants they grazed on the first rotation. In this way, producers can take advantage of the higher forage quality found on the extreme grazing treatment and still give plants a rest, thereby avoiding the reduced production also found on the extreme grazing treatment.

Future Research

We plan to continue this research for a number of years. Changes in the forage production and the plant species composition of the pastures are still continuing in response to the different grazing treatments and variation in annual weather patterns. These factors in turn will affect the animals’ responses to the grazing treatments. The pastures in this study are also being used for an ecosystem-modeling project conducted by Xuejun Dong.

Table of Contents

• Introduction
• Stocking Rate
• Livestock Response
• Effect of Grazing Intensity on Forage Production and Utilization, Soil Water and Forage Quality
• Plant Community Dynamics
• Recommendations