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, 



