SUDAN GRASS AND RELATED PLANTS. 49 
return of $47.47 an acre above the value of the grain fed. With 
the whole milk valued at 30 cents a gallon, each acre of pasture 
returned $73.55 above the cost of the grain consumed by the cows. 
Hogs provided with Sudan grass pasture make good gains with 
60 to 70 per cent of the customary grain ration. Some experi- 
ment stations have found that Sudan grass is not equal to alfalfa as a 
pasture for brood sows during the summer months. The alfalfa 
pasture is ready earlier in the spring and continues growth later in 
the fall. Sudan grass can not be sown until the soil becomes warm 
and it is generally killed by the first frost in the fall. 
The most serious drawback to the use of Sudan grass as pasture 
for cattle, horses, and sheep is the danger of prussic-acid poisoning. 
All sorghums contain small amounts of this acid, and under certain 
conditions, such as an acute drought, the quantity is likely to reach 
dangerous proportions. Both Sudan grass and Johnson grass are 
less likely to contain injurious amounts of prussic acid than the 
larger sorghums. This has been definitely proved by Menaul and 
Dowell (15), who found by careful analysis only one-third as much 
prussic acid in Sudan grass as in the grain sorghums. Very few 
cases of poisoning due to pasturing Sudan grass have been reported 
to the United States Department of Agriculture, but at least three 
authentic cases are known. In each of these instances the trouble 
occurred while pasturing the grass after it had been injured by drought 
or frost. Caution and good judgment are therefore required in 
pasturing Sudan grass with any kind of live stock other than hogs, 
which do not appear susceptible to this form of poisoning. 
SOILING AND SILAGE. 
Green feed for dairy cattle and work animals can be supplied as 
needed during the summer from a field of Sudan grass. It is well 
adapted to soiling, because the growth is renewed quickly after 
cutting, and it is relished by both cattle and horses in the green 
state. The cost of labor prevents any very extended use of soiling 
crops in the United States, although the return per acre of land is 
much larger by this method of furnishing a succulent feed than it is 
by pasturing. 
Sudan grass silage has been used very little, for three reasons: 
(1) Sudan grass can be easily made into hay; (2) there is little waste 
in feeding it as hay; and (3) both sorghum and corn, which can be 
grown in the same regions as Sudan grass, make larger yields of silage. 
Because of these facts there have been very few experiments with 
Sudan grass silage. The Oklahoma Agricultural Experiment Station 
(6, 8) has done some work along this line. Its earliest publication 
(Bulletin 115) is concerned chiefly with chemical analyses and tem- 
peratures. In the 1918 work reported by Dowell and Friedemann, 
