STOCKING RATE AND COW-CALF PRODUCTION ON SAND SAGEBRUSH RANGELAND

Authors: Gillen, Robert; Sims, Phillip

Submitted to: Journal of Range Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2002
Publication Date: 11/1/2002
Citation: GILLEN, R.L., SIMS, P.L. STOCKING RATE AND COW-CALF PRODUCTION ON SAND SAGEBRUSH RANGELAND. JOURNAL OF RANGE MANAGEMENT. 2002. v. 55. p. 542-550.

Interpretive Summary: Use of the proper stocking rate, the number of animals placed in a pasture to graze, is generally the most important management factor in sustainable grazing of Great Plains grasslands. Most previous research studies of stocking rate are limited by having compared only 3 individual stocking rates. Our objective was to determine the effect of a continuous spectrum of stocking rates, from low to high, on the performance of cows and calves and to determine the point where net economic returns might be maximized while still sustaining natural resources. The weight of cows declined as stocking rate increased because the amount of forage available to each animal declined as more animals were added to the pasture. Calf birth weight, average daily gain, and weaning weight all declined as stocking rate increased. However, the amount of calf produced per acre increased as stocking rate increased. This occurred because the decline in performance of individual animals was more than offset by the increase in the total number of animals. Net economic returns were maximized at a stocking rate considered to be slightly above moderate. By stocking 10% below this rate, livestock producers could reduce fluctuations in their annual net returns and reduce grazing impacts on natural resources while only reducing net income by 5%. However, as the selling price of livestock increases or as the gains of individual animals increases, producers will have an economic incentive to stock at higher rates.

Technical Abstract: Stocking rate is generally the most important management factor in sustainable grazing of Great Plains grasslands. Most stocking rate studies have compared only 2 or 3 discrete stocking rates. Our objective was to determine cow, calf, and economic performance on sand sagebrush (Artemisia filifolia Torr.) rangeland as a continuous function of stocking rate. Replicated stocking rates of 0.11, 0.15, and 0.22 head ha-1 were studied over an 8-year period. Cow weight declined as stocking rate increased in drought years but was not affected by stocking rate in wetter years. Weaning percentage was not affected by stocking rate but variation within treatment groups was high. Calf birth weight, average daily gain, and weaning weight all declined as stocking rate increased. Calf production cow-1 declined as stocking rate increased but calf production ha-1 increased. Net returns were maximized at $7.87 ha-1 year-1 at a stocking rate of 0.172 head ha-1, well within the range of experimental treatments. Net returns were within 5% of maximum between stocking rates of 0.156 and 0.183 head ha-1. The variability of all responses increased as stocking rate increased. Simulation indicated that improved livestock prices and increased animal productivity shifted the economic optimum stocking rate to higher levels, which would put more pressure on the conservation ethic of land managers.