32 



BULLETIN 947, U. S. DEPARTMENT OF AGRICULTURE. 



Comparing these results with those in Table 8, showing the effect 

 of feeding green leaves in the corrals, it is interesting to note that the 

 average quantity, about 2.5 pounds, necessary to produce acute 

 cases, is only slightly greater than the average quantity, fed in the 

 corrals for three weeks, which produced chronic cases — namely, 2.2 

 pounds. While as large a quantity as 3.143 pounds has been fed 

 daily for 22 days before producing intoxication, it is evident that 

 when the feeding is not made in a single dose, but is continuous and 

 spread over a considerable period of time, much of the toxic principle 

 must be eliminated. 



Continued Forced Feeding. 



In some animals the forced feeding of green leaves was continued in 

 smaller doses for several days. The following table shows those in 

 which positive results were obtained: ' 



Table 



-Forced feedings of green leaves, in tvio or more days, which produced intoxi- 

 cation. 



Animal. 



1915. 



Sheep 355 



Sheep 358 



Sheep 327 



Average 



Days 

 fed. 



Days. 

 3 

 3 



7 



44 



Number 

 of feed- 

 ings. 



Quantity fed per hundredweight of 

 animal. 



Total. 



Pounds. 

 4.001 

 4.139 

 7.936 



5.359 



Daily 

 average. 



Pounds. 

 1.33 

 1.379 

 1.134 



1.281 



Result. 



Died. 

 Sick. 

 Do. 



According to Table 7, an average daily feeding of 1.281 pounds 

 continued for 4 J days produced sickness or death, or, in round num- 

 bers, 14; pounds given daily for 4 or 5 days produced intoxication. 

 As compared with voluntary feeding upon leaves (p. 33) these force- 

 fed animals were poisoned on a smaller dosage and in less time. 



TOXICITY OF LEAVES OF PLANT. 



It is to be presumed that sheep on the range, when eating H. 

 hoopesii feed mainly on the leaves. It is of special interest, therefore, 

 to know the dosage of leaves that will produce sickness or death. A 

 large number of feeding experiments were carried on, and Table 8 

 summarizes the results of corral feeding of green leaves. 



