Oct. 1, 1925 
Abortion-Baderin Treatment of Gows 
669 
In the first guinea-pig inoculation test following the bacterin 
treatment of the cows it was demonstrated that 7 treated and 5 
control cows were eliminating the abortion organism in their milk; 
and in the second series of inoculations, 4 treated and 6 control cows 
showed infected udders. Before the third test was made one of the 
treated cows (No. 51) died. The third test indicated that 4 treated 
and 4 control cows were carriers of the microorganism. Five treated 
and 5 control cows produced milk that infected guinea pigs on the 
fourth test; 3 treated cows and 5 controls gave milk from which 
guinea pigs were infected on the fifth test; and 3 treated cows and 
5 controls gave milk from which guinea pigs were infected on the 
sixth test. 
The inoculation results indicated that the guinea-pig method of 
detecting Bact. abortus infection is by no means ideal or perfect. 
Not only was there a lack of uniformity in the results of the inocu¬ 
lation tests of milk of certain cows collected on different dates— 
irregularities which may have been due to an intermittent appearance 
of the infection in the milk—but the same sample of milk when 
administered to several guinea pigs in the same quantities frequently 
yielded conflicting results. The guinea-pig cultural results recorded 
m Table X plainly show that volumetricafly equal doses of material 
containing Bact. abortus do not always affect the animals in a similar 
manner. 
The number of bacterin-treated cows which continued to be carriers 
of Bad. abortus 608 days after the immunizing treatment, as 
indicated by the inoculation results, was 3, or approximately 43 per 
cent, while the number of controls was 5, or 62 per cent. Although 
the number of carriers after the treatment was larger in the control 
group, the difference did not appear to be sufficiently marked to 
justify the conclusion that the bacterin injections had any appre¬ 
ciable effect in overcoming the udder infection. Table XI shows the 
agglutination reactions that were obtained with blood serum from 
the 16 cows obtained on the different dates, and Table XII shows 
the agglutination reactions with the milk whey from the same ani¬ 
mals, as well as the milk yield for a 24-hour period preceding the 
collection of the samples. The blood reactions, while showing some 
variation in intensity on the different dates of collection, are more 
uniform, possibly, than might be expected when it is considered that 
a number of the cows, including Nos. 432, 17, 84, and 441, ceased, 
as far as the guinea-pig tests showed, to carry the infection in their 
udders for a period of from one to one and a half years. 
During the experiment comparatively few abortions occurred, 
while barrenness troubles were rather pronounced. The 15 cows 
which were carried through the experiment, continuing approximately 
two years, have produced 16 living calves. Five cows are now 
(April 3, 1924) heavy with calf. Cow 439 aborted a fetus in which 
Bact. abortus was present. Cow 84 aborted twice, the presence 
of Bact. abortus being demonstrated in the first abortion, but failure 
was experienced in isolating the organism in the second. Two of 
the cows (465 and 468) became pregnant only after ten services. 
Cow 247 seems to be permanently barren. Several other cows were 
bred five to six times before conception occurred. Table XIII gives 
some breeding data relative to the group since the experiment was 
undertaken. 
71486—26f-6 
