INCREASING FORAGE YIELDS ON INTERMOUNTAIN WINTER RANGES’ 17 
The weighted utilization of the three grasses taken together was also 
affected by the relative amount of total grass herbage available. In 
fact, the inverse relation of utilization to production was closer than 
that for any of the individual grass species. 
TABLE 4.—Average herbage yield, proportion of total, and herbage utiliza- 
tion of four major forage species in moderately grazed range pastures, 
1938-46 
Species and Herbage Proportion of Herbage 
pasture number yield total yield utilization 
Winterfat: Pounds per acre Percent Percent 
Sie eee ee ee 4 2 (7 
Oe en nce erie 6 3 59 
Qasr et ses 15 8 58 
eee eg ONS ee ees 28 15 62 
OX gee ara eS ee ae 90 45 49 
QE Cee 109 51 54 
Gi ee 118 51 48 
Indian ricegrass 
0 Fe SO aaa eee ew 5 3 73 
Qe esc ee 6 3 92 
EGE Pee ee ee a Nes 7 3 91 
7) Se OSES Se pls Ba 8 4 82 
Dee rg SER Fires a 9 5 77 
Dee ec ese meee ney Ga 19 10 60 
Gree Ps ie ee 21 11 66 
Galleta: 
(Gea e  Raa ees 9 8 29 
DO'S eae eI ES 12 6 73 
7d es cepts eRe aia 14 7 58 
QE ie se 15 7 65 
Oe ee ae St when SS ae 25 13 32 
Oe Fe i Soe ee EONS ieee 25 14 39 
DOR na oR ee 26 14 o4 
Sand dropseed: 
JI GPS es eacrnecne a ee a (#) (?) 48 
[Os Sele a a 1 (2) 57 
7d 0 ee RTs tee Dee a 6 4 28 
(DRESS ST oe ieee Se 24 12 9 
yen are pera cca te ea Ne ae 31 16 8 
De AS 37 21 20 
1S BU es ere ona ae 56 30 IL 
' Less than 1 pound per acre. 
2 Less than 1 percent. 
The degree of use of a grass species is affected by the relative avail- 
ability of herbage of other grasses. Sheep strive to include a certain 
amount of grass in their diet. If they cannot obtain it from the choice 
Indian ricegrass, they eat more galleta and sand dropseed. Utilization 
of galleta and sand dropseed was low in pastures 5 and 6, where Indian 
ricegrass yields were the greatest. In pastures 16, 19, and 20, where 
all three grasses were most heavily grazed, yields of Indian ricegrass 
and the other two grasses were relatively low. 
