146 DESCRIPTION OF FEEDING STUFFS 
According to Jaffa,?* sheep and cattle have subsisted altogether 
on salt bushes through an entire season, and sheep feeders and cattle 
men report favorably as to their nutritive value when eaten in con- 
nection with hay and grain feeds. 
Spineless cacti (species of Opuntia, Fig. 26) and prickly pears 
are desert plants used as a forage for cattle in cases of emer- 
gencies, and occasionally in a limited way as a regular forage crop. 
There are many varieties of cacti used for this purpose, some with, 
some without spines. The former are generally singed with a spe- 
cial gasolene torch before being fed to farm animals, while the 
latter are fed directly, either whole or after being run through a 
Fia. 26.—Spineless cactus yields large crops of a very watery feed under favorable con- 
itions; it is greatly relished by cattle and hogs. 
cutter. There is no material difference in the chemical composition 
of the two kinds of cacti. In the case of either kind the composition 
of the plants will vary according to the parts analyzed. The older, 
somewhat woody stems contain less water than the young, succulent 
joints. Cattle appear to prefer the more mature joints, and doubt-' 
tess derive the greater amount of nutriment from these. Spineless 
cacti will contain 75 to 92 per cent of water (average about 85 per 
cent), about 0.9 per cent protein, 2.6 per cent fiber, 14.7 per cent 
nitrogen-free extract, 0.4 per cent fat, and 4.2 per cent ash. As 
might be expected, the ash content and the nitrogen-free extract 
are very high, while protein is relatively low; it is, therefore, a 
starchy feed and has a very wide nutritive ratio. 
*% California Bulletin 132, 
