ORIGINAL ARTICLES
INCIDENCE OF BRUCELLOSIS IN DAIRY HERDS IN BENGAL
By RAM NARAIN MOHAN, Veterinary Investigation Officer, Bengal
(Received for publication on 5 July 1945)*
A S in other Provinces, attention to contagious abortions in cattle in Bengal followed the inception
in 1932 of the scheme for the appointment of a Veterinary Investigation Officer, with the help
of funds from the Indian Council of Agricultural Research. The observations made have been recorded
in the various annual reports of the officers, but it has been considered advisable to present the
results in a consolidated form, especially because Polding's [1943] publication dealing with incidence
of Brucellosis in India does not cover Bengal and Assam. Moreover, though the broader features
of the abortion disease in organized herds in Bengal have been found similar to those noted elsewhere,
some of the observations have been quite interesting and instructive.
METHODS
In the earlier period, from 1934 to 1941, the investigations were restricted chiefly to one or two
important herds, at least one of which suffered a serious outbreak of abortions and still-births. Speci-
mens of blood serum taken from aborting and other animals of these herds, were, from time to time,
and often repeatedly, despatched to the Indian Veterinary Research Institute, Mukteswar, where
they were subjected to the standard tube agglutination test. Later on, from 1942 to 1945, when
periodical consignments of suitable antigen and a portable outfit for a quick slide agglutination test
were received from Mukteswar, the survey was extended to some more, herds located in different
parts of the Province. Unpreserved specimens of blood serum, generally from all available adult
stock and sometimes including a few grown-up calves, were tested on the spot within a few to 24
hours, taking the usual precautions. The reactions obtained were mostly clear-cut and the percen-
tage of doubtful reactions was small.
While some consignments of antigen went bad comparatively soon, others remained well and
discriminatingly agglutinable (checked against fresher consignments) for long periods, in one case for
more than a year at room temperature.
The occurrence of positive reactions in any herd was regarded rather as an indication of the
presence of infection in the herd than a correct and dependable index of the extent of infection. The
herd owners were advised accordingly and, where necessary, suitable hygenic control measures
were prescribed.
RESULTS
The main results are summarized in Table I. Brief notes concerning individual herds and history
of abortions, etc. in them are also given. It will be seen that out of thirteen herds tested, Brucella
infection was definitely demonstrated in only eight. Herd No. 1, originally composed of Welsh
and Sahiwal cattle and believed to have been previously free from infection, suffered a serious out-
break of the disease following the introduction of a batch of Jersey cattle from Australia in February
1934. The following figures give an idea about the spread of the disease in this herd.
Year
1934-35
.
.
.
.
.
1935-36
.
.
.
.
.
1936-37 . . . . .
1937-38 . . . . .
Average number of cows in the
herd
75 (18 Jersey) . . .
84 ( do. ) . . .
98 (25 Jersey) . . .
100
.
.
.
.
.
Abortions
7 (All in original herd) . .
30 (3 Jersey) . . . .
19 (6 Jersey) . . . .
11 (9 Jersey) . . . .
Percentage
9.3
35.7
19.4
11.0
*Resubmitted for publication on 28 July 1947.
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