16 circular 870, u. s. department of agriculture 



Supplementing Range Forage During Critical Periods 



Although best adapted for grazing during the approximately 4 months 

 of adequate green forage, foothill ranges are of necessity grazed at other 

 times of the year. Only a limited acreage is used solely in the spring, 

 when the forage would promote most efficient livestock gains. The 

 foothills are the chief source of range forage during the fall and winter. 

 In many operations the livestock are kept on these ranges during the 

 entire year. Whenever foothill grazing extends beyond the green-forage 

 period, the natural range forage is now commonly supplemented during 

 part or all of the time that it is deficient. 



A practice of supplementing foothill range forage was developed by 

 the Division of Animal Husbandry, University of California, in their 

 part of the studies at the San Joaquin Experimental Range (2, 13). 

 Here, where there is little bur-clover, the practice is to feed 1 pound of 

 43-percent cottonseed cake per day per cow while depending on dry 

 range forage during the summer. This amount is increased to 1J^ to 2 

 pounds per day in September or October (before the start of calving), 

 after the better forage species have been removed by grazing through the 

 summer and fall. Rolled barley, at 1 pound per day, is added as a source 

 of energy-producing carbohydrates after the first effective fall rains. 

 Supplements are decreased gradually as new green forage becomes more 

 abundant in late winter. The daily amount of feed is increased slightly 

 in years when there is a low proportion of grass and clovers, when the 

 dry forage is leached by late spring rains, or when cattle weights are below 

 average. 



Ranchers must also take into account the year-to-year variations in 

 the length of the period with adequate green forage. During 14 years 

 of study the average length was 127 days, but the period varied from 

 72 days in 1944, 43 percent below average, to 176 days in 1935, 39 percent 

 above average. Variations between 15 to 30 percent above or below 

 average occurred in four other years. For operations in which cattle 

 are moved onto foothill ranges during the winter and moved off in late 

 spring, the variations can be met by purchasing supplemental feeds, 

 moving to other sources of range forage, or varying the date of buying 

 and selling stockers and feeders. For operations in which the cattle are 

 on foothill ranges the entire year, or from fall until late spring, such 

 variations can be met only by supplying sufficient feed to supplement 

 the deficiencies in the natural range forage. 



How the amount of supplements needed may differ from year to year 

 because of variations in the forage crop is suggested by records at the 

 experimental range. Supplemental feeding was started several weeks 

 later than desirable in some years because the cows to be supplemented 

 were mixed with unsupplemented cows in the grazing-intensity pastures 

 until about August 1. Nevertheless, for 10 years (1937-46) the yearly 

 supplement per cow varied from 288 to 462 pounds (13). 



Supplements increased cattle production. Averages reported for the 

 first 7 years (2) show a calf crop of 83.0 percent for the herd fed supple- 

 ments and 67.6 for the herd not fed supplements; calf weaning weights 

 at about 8 months of age were 470 and 417 pounds, respectively. An 

 average of 365 pounds of supplemental feed yearly produced 108 pounds 

 more calf weight per breeding cow in the supplemented herd. 



