34 CIRCULAR 804, U. S. DEPARTMENT OF AGRICULTURE 



more palatable than they are later. These species, plus the blue 

 grama and the many forbs of the rolling areas, should carry the burden 

 of grazing until late fall, when storms encourage movement to the 

 rough hills for browse and coarse grass forage as well as the protection 

 such areas afford. Range areas especially adapted to grazing during 

 critical winter or early spring periods should be reserved throughout 

 the summer and early fall in order to have them in good condition 

 when urgently needed. Some variation from this plan of seasonal 

 use may be necessary to obtain the use of all areas to the best ad- 

 vantage on individual ranges. 



Conservative stocking, frequent utilization checks, and regulated 

 seasonal grazing will not insure phenomenal success in range sheep 

 production or wholly eliminate the risks incident to a drought, but 

 they will stabilize operations over a long period of time and help to 

 perpetuate the range resources. 



RECOMMENDED STOCKING RATE FOR NORTHERN 

 GREAT PLAINS SHEEP RANGE DURING AVERAGE 



8- to 9-MONTH SEASON 



Rate of stocking, the relative intensity of animals on a range, is 

 usuaUy expressed as the number of acres of range allowed for each 

 animal for a specific period. It may also be expressed in numbers of 

 livestock per section (64 j acres) of range for the period. Range 

 managers find such numerical expressions useful, but recognize that at 

 best they are only guides to grazing capacity on comparable ranges. 

 Such a guide must be checked against results of stocking on a given 

 range and changes made as required to avoid stocking too heavily 

 for safety or too lightly for best results in the long run. 



During the 6 years of the grazing experiment, 1936-41, the stocking 

 was increased each year after 1936 (table 1, p. 4, and fig. 13) in all 

 pastures as the range recovered from drought. This was accom- 

 plished in 1937 by lengthening the grazing season and in 1938 to 1941 

 by annual increases in the number of sheep grazed, which brought 

 corresponding reductions in acreage per head. Precipitation in- 

 creased materially each year, except 1939, during the period (fig. 13). 

 With the favorable weather forage production increased also, as 

 judged by the amount of unused forage left on the ground at the 

 end of each grazing season. 



In 1941. the last year of the test, when the range had recovered 

 somewhat from drought and weather was quite favorable for growth, 

 the middle-sized pasture was stocked at the rate of 0.56 surface acre 

 per month per yearling ewe. 



A margin of safety in allotting range forage is essential because dry 

 or drought years of low forage production often occur. If there is no 

 such margin or reserve of forage, abnormal expense for supplemental 

 feed or heavy liquidation may be necessary in order to avoid disastrous 

 sheep losses. Although no supplemental feeding was done in the 

 experiment, it would have been required in the heavily grazed pasture 

 had the sheep been left on the range any longer each season. The 

 quantity, cost, and availability of supplemental feed reserves to meet 

 such emergencies on a ranch should be considered in determining the 

 additional range area needed to assure stability and safety for the 

 range operator. Twenty percent of additional range is the recom- 



