3. By way of substitution of the young one of a parti- 
cular breed with a young one brought from farms which are with- 
out brucellosis and the raising of healthy flock from this 
young one in isolated farms. 
This is done in farms where brucellosic isolators are 
present and also in collective and state farms, where the iso- 
lators are thoroughly liquidated but the isolation of the 
animals positive for brucellosis is not stopped for a long time, 
4, By the method of substitution of the entire herd having 
brucellosis with healthy animals from farms free of brucellosis. 
This method is applied for the sanitation of sheep and swine 
farms against brucellosis, as well as for the sanitation of the 
cattle in areas and regions where there are solitary farms 
having brucellosis. which have not been subjected to other 
methods of sanitation for a long time. 
According to the data of many investigations, the young 
cattle, especially at an earlier age, possess high natural 
resistance against brucellosis. On this basis, for the liquida- 
tion of brucellosis in farms having brucellosis, isolated 
raising of the young cattle is done for the creation of a 
healthy herd. However, a series of contradictory data have been 
published. In our republic, there are examples where implement- 
ation of well thought-out system of measures on the raising of 
healthy herd from the young cattle obtained from the cows of the | 
herd having brucellosis ended in failure. Thus, in the collect- 
ive farm "Nove Zhitia'' of the Dnepropetrovsky region, after the 
establishment of diagnosis for brucellosis, all cows of the herd 
having brucellosis were given for slaughtering and the young 
cattle obtained from these were left behind on the farm. After 
carrying out the necessary sanitary measures for more than one 
year restrictions for brucellosis were Jifted from the farms. 
Within 11 months after this, the collective farm s01d out 80 
calves to a farm without having brucellosis in any other region. 
Before taking out from the farm and in the period of prophylac- 
tic quarantine, these calves gave negative results for brucello- 
Sis. However, abortions were registered after pairing among 
them and in the remaining calves left at the farm. From the 
fetus, a culture of brucellosis was isolated and with serolo- 
gical investigations of blood after PA and PCK many animals gave 
positive result for brucellosis. 
By taking into account the above-mentioned facts in a series. 
of farms having brucellosis, the calves were replaced by the ones 
a be 
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