CHAPTER XII 

 STOCK-POISONING PLANTS AND THEIR CONTROL 



Notwithstanding the improved methods of management 

 adopted by stockmen more or less generally in recent years, the 

 livestock industry is nevertheless confronted with some very 

 difiticult problems. One of the biggest problems is the enormous 

 annual toll of stock losses due to disease, predatory animals, 

 injurious plants, and accidents of all sorts. Two phases of this 

 problem, outside, of course, of bacterial pathology, come within 

 the domain of botany, viz., (i) the existence of poisonous plants, 

 many of which are devoured by livestock often with fatal effect ; 

 and (2) the presence of plants which at some stage in their de- 

 velopment cause mechanical injury, not uncommonly weakening 

 the animal seriously and sometimes causing death. 



The poisonous-plant problem is most serious in the far West 

 where the losses each year are very heavy — sometimes, indeed, 

 outnumbering the combined losses caused by contagious and 

 infectious diseases and by predatory animals. On the National 

 Forest range alone approximately 8,000 cattle and 20,000 sheep, 

 valued at about $500,000, die annually from the eating of 

 poisonous plants; yet the acreage of National Forest range is 

 only a small part of the grazing grounds of the West. More- 

 over, the percentage of losses from poison on the high mountain 

 Forest range is probably less than on ranges of lower ele- 

 vation, especially the public-domain lands, most of which are 

 badly overgrazed. Losses in the plains region from loco, for 

 instance, each year vary from 5 to 50 per cent of all the stock 

 grazed. 



Stockmen may prevent much of the heavy financial loss now 

 241 



^-- 



