SHEEP-FEEDING TESTS WITH GREEN MATERIAL, 1918-1919 



As a result of the twenty feeding tests, 7 sheep were poisoned, 5 of 

 which died. The weight of green material required to make a sheep sick 

 or to kill it varied from 1J pounds to 4J pounds, the average fatal dose 

 being approximately 2.4 pounds. Because of the extremely irregular 

 way in which plants containing hydrocyanic acid act on animals, it 

 would be difficult to state accurately just how much of the plant is 

 required to kill a sheep or to make it sick. 



However, the above tests demonstrate conclusively that arrow-grass 

 is a plant containing an active poison, and, although the amounts neces- 

 sary to produce sickness or death may seem high, in reality they are 

 not"; for the plant is made up of a rather open cellular structure con- 

 taining a high percentage of water. Further, when poisoning does 

 take place death is likely to follow; this is shown by the fact that of 

 7 animals poisoned 5 died. Four of the deaths were caused by 2J 

 pounds or less of green material. 



A series of feeding tests with cattle made in spring, summer and 

 autumn with green arrow-grass failed to cause poisoning. The tests 

 are summarized in the table at the top of page 13. 



Two pounds of green arrow-grass had no effect on Steer No. 735. In 

 October this animal ate an average of 15J pounds daily for 7 days or 

 a total quantity of 110J pounds, with no bad effects. The material 

 for this test as shown in the table was collected during October. The 

 June feeding tests also resulted negatively. 



These results cannot be taken to mean that fresh green arrow-grass 

 is not poisonous to cattle; for we must constantly keep in mind the 

 irregular and apparently inconsistent action of plants containing 

 hydrocyanic acid. There is. a possibility that under different condi- 

 tions of feeding and at another time the feeding of the same quantity 

 or even less would have caused poisoning. Many valuable forage plants 

 in the sorghum group contain hydrocyanic acid; and yet they are 

 ordinarily fed without causing losses. However, on the other hand, 

 ratner serious losses in cattle have been caused by the sorghums. With 

 arrow-grass, the same erratic action may be expected. This test would 

 seem to indicate that pastures where arrow-grass grows are ordinarily 

 not dangerous to cattle; still, there is always a possibility that they 

 may eat just the right amount at the right time with deadly results. 



