200 FEEDS AND FEEDING, ABRIDGED 



they become very emaciated. Fed in large amounts with no dry feed 

 cacti tend to produce scours. 



Spineless cacti, long known, but of late exploited as a novelty, have 

 only limited usefulness for stock feeding, both because they do not 

 survive where the temperature falls below 20° F., and because on the 

 open range cattle readily destroy them. Moreover, in the West, they 

 must be enclosed by rabbit-proof fences. 



The chief importance of cacti will undoubtedly be to furnish emer- 

 gency forage for stock in the semi-arid plains regions. For this pur- 

 pose plantations of the spiny cacti may be established on the open 

 range, where they will be able to grow and hold their own until drawn 

 upon in time of serious drought, for cattle will not graze them when 

 other feed is reasonably abundant. All cacti have little value in 

 humid regions. 



III. Poisonous Plants 



Only the briefest mention can be made of the leading plants poison- 

 ous to stock. One in trouble should send suspected specimens to the 

 experiment station of his state, or to the United States Department of 

 Agriculture. 



Plants carrying prussic acid. — Prussic acid, a deadly poison, is 

 found in many plants. The leaves of the wild cherry, especially 

 when wilted, are particularly fatal to cattle. When the sorghums, 

 both sweet and grain varieties, are stunted by drought, enough prus- 

 sic acid may develop to kill cattle grazing on them. Caution should 

 be used in feeding stunted or second-growth sorghum, kafir, Johnson- 

 grass, etc. Wilted or cured sorghum and sorghum silage are not 

 poisonous. 



Ergot. — The seeds of rye and many of the grasses are sometimes 

 attacked by a fungus which produces poisonous black masses known 

 as ergot. Affected animals should have their feed changed to remove 

 the cause, and be warmly housed and liberally fed. 



Forage poisoning. — During recent years serious losses of stock 

 have occurred from forage poisoning, or "blind staggers," caused by 

 eating moldy feed or drinking water that has passed thru moldy 

 vegetation. Horses and mules succumb most easily but cattle are also 

 affected. The mortality is high in well-developed cases; therefore, 

 animals showing the slightest symptoms should have their feed 

 changed. If moldy feed must be given, it should be fed sparingly 

 and mixed with other feeds of good quality. 



Cornstalk disease. — All efforts to determine the cause of a mysteri- 

 ous and fatal ailment, called corn-stalk disease, which attacks cattle 

 turned into stalk fields during fall and winter in the West, have 



