70 
BULLETIN 365, U. S. DEPARTMENT OF AGRICULTURE. 
Jt/A/£-* JULY * /4UGC/ST * S£f7r 
25 30 5 IO 'S 20 25 30 A 9 /4 /9 24- 29 3 8 S3 
/30 
/20 
k t/O 
80 
V) 
* 50 
40 
30 
♦ 
• 
< 
i 
Fig. 10. — Chart of feeding of Delphinium barbeyi to cattle 
experimentally poisoned in 1909 based on weekly aver- 
ages. The weights of plant are given per thousand 
pounds of animal. 
toxicity plays a more important part in those years. The average 
toxic dose for 1 day's feeding in 1910 was 54.9 pounds, and in 1911 
it was 69.5 pounds. It thus appears that, in the general average of 
cases, cattle weighing 
1,000 pounds will be 
poisoned if they eat 
as much as 60 pounds 
in one day. This 
quantity varies, how- 
ever, within wide 
limits, in one case 
being as low as 30 
pounds, and at the 
other extreme as 
high as 93.3 pounds. 
A tabulation of 
the quantities eaten 
the first day by ani- 
mals poisoned in 2, 
3, or 4 days shows that few exceeded the toxic limit; of 15 cases 
in 1909, No. 115 ate 37 pounds, No. 98 ate 58.16 pounds, and No. 112 
ate 56.5 pounds. Of 15 cases in 1910, No. 612 ate 43 pounds, No. 610 
ate 36 pounds, and 
No. 121 ate 38 
pounds, while in 
1911, of 6 cases, No. 
639 ate 62.2 pounds 
and No. 647 ate 46 
pounds. It will be 
noticed that only one 
of these exceeded the 
average quantity 
which poisons in 1 
day's feeding, but 
that all exceeded the 
minimum. 
While some of the 
differences in the 
toxic dose can be ex- 
plained by seasonal 
differences in the plants and the duration of feeding, many remained 
unexplained. These differences, under apparently the same condi- 
tions, are shown in cases 637, 646, 639, 647, and 640 of 1911. All these 
animals were fed between July 25 and July 31, with the following 
Jt/A/£ x JOJ. Y x SIOGISST 
1 5 W /S SO 2S 30 & /O /S 20 2S 30 4 9 /4 /9 24 
150 
140 
130 
120 
k 
^ /oo 
& 90 
t0 80 
■M 
^ So 
so 
40 
30 
• 
• 
• 
1 
• 
• 
< 
1 
Fig. 11. — Chart of feeding of Delphinium barteyi to cat- 
tle experimentally poisoned in 1910 based on weekly 
averages. The weights of plant are given per thou- 
sand pounds of animal. 
