30 
BULLETIN 947, U. 
DEPARTMENT OF AGRICULTURE. 
hie, however, that to be absorbed in the rumen or reticulum it must 
be in sufficient concentration to damage the epithelium. 
TOXIC DOSE FOR SHEEP. 
In determining the toxic dose a distinction should be made between 
poisoning by a single administration of the plant and the toxic result 
of prolonged feeding. It was found that no animal would eat enough 
in a single day to produce symptoms, but by the use of the balling 
gun it could be compelled to swallow enough to produce intoxication 
or death. Moreover, the whole aerial part of the plant including 
stems, leaves, and flowers was used with some animals while in other 
cases use was made of stem leaves, radical leaves, flowers or sterns, 
leaves, and fruit. 
Toxic dose of whole plant, including leaves, sterns, and flowers when 
fed. — Eight sheep were used in the feeding of the whole plant in 1915 
and two in 1916. Table 5 shows the result: 
Table 
-Summary of feedings of leaves, stems, and flowers. 
Animal. 
Sheep 316. 
Sheep 319. 
Sheep 326. 
Sheep 328. 
Sheep 329. 
Sheep 333 . 
Sheep 344 . 
Sheep 346 . 
Sheep 386. 
Sheep 38.5 . 
1915. 
Average . 
Total 
fed. per 
hundred- 
weight 
of 
animal. 
Pounds. 
2.19 
S2.468 
43. 299 
74. 713 
32. 865 
28. 372 
2.469 
80.311 
77. 166 
49. 074 
Total 
days 
fed. 
Bays. 
1 
21 
28 
19 
17 
24 
3 
59 
Average 
daily- 
feed per 
hundred- 
weight 
of 
animal. 
Pound. 
2.19 
3.9 
1.546 
3. 932 
1.933 
2.182 
.835 
1.361 
1. 434 
1.363 
Days 
before 
sick. 
Quan- 
tity per 
hundred- 
weight 
of 
animal 
to 
produce 
sickness. 
Days. 
Pounds. 
Pounds. 
21 
75.3 
3.1 
19 
74. 713 
3.9 
24 28. 372 
"23' ""35.7"" 
20 37. 579 
23 34.626 
21.6 
Daily 
average 
to 
produce 
sickness. 
Result. 
Not sick. 
Died. 
Not sick. 
Sick. 
Not sick. 
Weak. 
Not sick. 
Symptoms 
1.879 Very sick. 
1. 505 Do. 
2.17 
In all the cases of 1915 except sheep 310 the animals were given 
only the H. hoopesii. In the cases of 1 91 6, hay was fed with the plant. 
Averaging these cases, a daily feeding of 2.17 pounds continued 
21.6 days produced sickness or death. The limits of the daily dosage, 
however, were rather wide, varying from 1.18 pounds in Sheep 333 to 
3.9 pounds in Sheep 328. There was nothing in the conditions of 
the experiments to explain this wide divergence. 
TOXIC DOSE FOR CATTLE. 
Cattle 824 was made sick in 21 days, receiving in that time 52.6 
pounds while Cattle 827 was made sick in 39 days, receiving in that 
time 48.32 pounds. The two cases average in 30 days of feeding with 
