28 CIRCULAR 870, U. S. DEPARTMENT OF AGRICULTURE 



"failure" of herbage production occurred in the vicinity of the experi- 

 mental range from 1877 to 1948. In years of extremely low precipitation, 

 however, severe forage shortages undoubtedly occurred during a con- 

 siderable part of the plant-growing season, and a shortage of water for 

 stock limited effective use of the forage after it dried. 



Stocking to Meet Forage Fluctuations 



To meet the fluctuations in the forage supply and obtain efficient 

 utilization of annual plants, some adjustment in stocking is needed nearly 

 every year. Whether a change in numbers of livestock is needed can 

 be judged in late spring, after almost all plant growth is complete, and 

 again at weaning time in the summer or fall. The extent of adjustment 

 and the classes of stock involved will depend on the type of operation 

 at each ranch. 



For ranches keeping the cattle on foothill range during all or most of 

 the year, the desirable flexibility can be had by operation of a breeding- 

 cow herd in which all or part of the calves are generally carried over and 

 sold at the end of the next green-forage season as long-yearlings. Essen- 

 tially, this practice consists of carrying enough cows and replacements 

 to utilize most of the forage in the years when yields are well below aver- 

 age. During the five dry years at the experimental range, total herbage 

 production was reduced a little more than 25 percent below average in 

 two of the years, but only about 10 percent below in two other years. 

 Probably the cow herd should not take more than 75 percent of the usable 

 herbage in average years. 



The extra forage in years of average production is utilized by yearlings. 

 If there is no extra, the young stock can be sold as weaners. In years of 

 above-average herbage production the increased forage yield may either 

 be utilized by bringing in outside animals, or be left on the ground to 

 replace any litter than may have been lost during dry years. 



If a year of very low herbage production occurs when maximum numbers 

 of yearlings are being carried, some animals can be sold earlier than usual 

 to save range roughage for use by the cow herd during the summer, fall, 

 and winter. Other adjustments can be made by heavier culling of cows 

 and replacements and possibly by earlier weaning. 



Almost yearly changes in stocking are necessary because a reserve of 

 forage cannot be built up on the ground in good years. Dry herbage of 

 annual plants is ruined by leaching during the winter. It appears feasible, 

 however, to keep a reserve of hay above the usual yearly needs {12). This 

 hay reserve, often obtainable at a lower cost before the start of a drought, 

 can be stored under cover with little deterioration. Besides filling part 

 of the needs for roughage in years of low grass production, the hay may 

 be needed in other emergencies, as when growth of green forage is greatly 

 delayed in late winter or when grass fires cause sudden loss of dry vegeta- 

 tion. 



Experience with both a breeding herd and yearlings at the experimental 

 range indicates that the foregoing method of operation is feasible and 

 will allow the necessary adjustments in livestock numbers in all except 

 the occasional years of extremely low herbage production. 



Fluctuations in the composition of the herbage crop should also be 

 considered in stocking foothill ranges. The amount of grass in the plant 

 mixture is of special importance on ranges grazed from summer until 



