20
As the Department extends and inoculation work develops, the demand for
this serum will, doubtless, increase greatly.
113. Mallein.—3,407 doses of Mallein were prepared at Muktesar, against
1,514 doses last year, and 2,606 doses were indented for during the year. The
demand can now be met in India.
114. Tuberculine.—There has been practically no demand for Tuberculine
excepting for experimental purposes.
115. In addition to the preparation of this large amount of serum,
research work has also been carried on in various directions. In regard to
Rinderpest serum, experiments were conducted with a view to determine the
protective value of various anti-Rinderpest sera, prepared by hyper-immunizing
different breeds of cattle with virulent blood obtained from the same and other
breeds, after allowing periods varying from five and-a-half to six years to
elapse, during which intervals the sera were deposited at Muktesar. It was
found that:—
(i) Plains animals hyper-immunized with hill blood, the serum lost 33
% of its protective value in six years.
(ii) Hill bull hyper-immunized with virulent hill blood, the serum
retained its previous protective power after six years.
(iii) Buffalo hyper-immunized with virulent blood, the serum had lost
none of its protective power in six years.
It will be seen therefore that a higher protective serum results from
hyper-immunizing an animal with virulent blood from the same species.
116. Some serum No. XXII which had been kept for a year in a pit at
Nagpur, was tested and found to have lost little of its protective power.
117. Work has been continued with Piroplasmosis, Trypanosomiasis, and
it has been ascertained that 50 % or more of all plains bulls, and the majority
of hill bulls at the Laboratory, are the subjects of Piroplasma in one form or
another. A separate report will be issued dealing with these two diseases.
118. Doctor Lingard records the discovery of a spirillum in the blood of
cattle and notes that (i) it was impossible to convey the spirillum by subcuta-
neous inoculation of blood to either monkeys or other small animals, (ii) that
the spirillum could not be found in ticks, (iii) that emulsion of ticks removed
from a sick bull did not produce the disease on subcutaneous inoculation into
healthy animals. The spirillum therefore seems to differ from that discovered
by Theiler in South Africa.
119. In the hyper-immunization of cattle against Anthrax, considerable
saving of time, labor and a great reduction in the quantity of culture material
utilized, as well as a minimum risk to those conducting the operations has been
secured by the introduction of the use of the intravenous method of injecting
bovines used for the purpose.
120. Numerous interesting points regarding Hæmorrhagic Septicæmia
have been worked out, and as before stated a polyvalent anti-bacterial serum
has been produced, which confers on plains animals a passive protection against
the inoculated disease for a month at least.
121. In this connection the following results obtained with the serum of
bovines immunized with the causal agent of Hæmorrhage Septicæmia :—
(i)—The disease does not appear to infect by the gastro-intestinal canal,
unless an abrasion exists.
(ii)—Hill animals require a larger dose of anti bacterial serum, than
plains animals to produce protection.
(iii)— The protection of plains animals lasted 4 weeks, but had disap-
peared in 7 weeks, whilst the same dose did not protect hill
animals for 8 days.
(iv)—Active immunity can be produced by the simultaneous method.