612 
Journal of Agricultural Research 
Vol. XXVIII, No. 7 
Table I,— Immunization results in animals subjected to artificial exposure to 
Bacterium abortus —Continued 
TREATED WITH ABORTION BACTERIN 
Experimental 
animal 
Date of 
treatment 
Date of 
breeding 
Date of 
exposure 
Exposure 
material 
(fetal 
stomach 
con¬ 
tents) 
Ges¬ 
ta¬ 
tion 
Outcome of 
pregnancy 
Results of 
uterine ex¬ 
amination 
6 
£ 
©. 
w 
CJ 
o 
4^ 
a 
a 
o 
S 
< 
pe¬ 
riod 
for Bad. 
abortus 
Heifer 423- 
Feb. 1,1917 
Mar. 23,1917 
June 8,1917 
21 
Cc. 
50 
Days 
282 
Living calf,_ 
Negative. 
Heifer 401. 
Mar. 2,1917 
Apr. 2,1917 
May 2,1917 
June 7,1917 
July 2,1917 
Aug. 4,1917 
Sept. 4,1917 
Oct. 5,1917 
Nov. 3,1917 
Dec. 3,1917 
Dec. 7,1917 
June 5,1918 
Aug. 8,1917 
Aug. 20,1918 
Jan. 5,1918 
70 
54 
25 
30 
231 
273 
Abortion—.. 
Living calf. - 
Do. 
Do. 
Heifer 404_ 
Jan. 2,1918 
Jan. 22,1918 
Feb. 2,1918 
Mar. 4,1918 
Mar. 25,1918 
Apr. 15,1918 
Feb. 1,1917 
Sept. 23,1918 
Oct. 14,1918 
May 24,1917 
Nov. 3,1918 
June 7,1917 
74 
21 
20 
50 
278 
162 
.do. 
Abortion.. 
Do. 
Positive. 
Heifer 464. 
Mar. 1,1917 
Apr. 2,1917 
May 2,1917 
June 2,1917 
July 2,1917 
Aug. 4,1917 
Sept. 4,1917 
Oct. 5,1917 
Oct. 5,1917 
June 25,1917 
Nov. 2,1917 
42 
5 
238 
.do. 
Do. 
Oct. 20,1917 
Nov. 2,1917 
Nov 16,1917 
Dec. 3,1917 
Dec. 18,1917 
Jan. 2,1918 
Jan. 31,1918 
Feb. 14,1918 
CONTROLS 
Heifer 446 
Heifer 422 
Heifer 460. 
Heifer 450. 
Heifer 413. 
May 4,1917 
May 4,1917 
June 16,1917 
Aug. 16,1917 
May 9,1917 
Heifer 430 
Jan. 7,1919 
Cow 470. 
Cow 453. 
Feb. 24,1919 
Dec. 18,1919 
June 8,1917 
June 8,1917 
Nov. 2,1917 
Dec. 13,1917 
June 8,1917 
r Feb. 24,1919 
[Mar. 19,1919 
May 24,1919 
May 10,1920 
21 
50 
182 
Abortion.... 
Positive. 
21 
50 
177 
_do- 
Do. 
42 
5 
265 
_do.. ... 
Do. 
54 
30 
241 
.do_ 
Do. 
21 
50 
206 
_do_ 
Do. 
80 
88 
20 
25 
} 223 
_do- 
Do. 
92 
50 
266 
Living calf. - 
Do. 
126 
22 
186 
Abortion.... 
Do. 
The source of the fetal-stomach contents used for exposure purposes is indi¬ 
cated in Table I in order that animals receiving similar exposure may be readily 
identified. The fetal material was transferred to sterile flasks at the times the 
fetuses were cultured and was held at refrigerator temperature until cultural 
results were ascertained. 
It may be observed by reference to Table I that seven vaccinated animals 
were carried through a second period of pregnancy without further administration 
of vaccine and that living calves were produced in all cases. Failure was further¬ 
more experienced in demonstrating the presence of Bacterium abortus in the 
placentas or uterine fluids of these animals at time of parturition. Four of the 
