December, 1951]
ABSTRACTS
265
The type of reaction has no relation to the degree of immunity. The field strains also
vary in their virulence, which points out towards multiplicity of rinderpest virus
strains and for the same reason the antigenic value of the G. T. V. produced in the
State may vary.
The period of immunity in hill cattle is mentioned as 10 years and 3 to 5 years
in the Plain cattle. Degree and duration of immunity can be increased, by keeping
the vaccinated animals away from the heating effects of the sun, i.e. by vaccinating
them in winter; and by giving protein rich food to stimulate the antibody formation
in the body. The author prefers the subcutaneous system of inoculation to scari-
fication method, because of the severity of reaction obtained in the latter and because
of its being more or less an intra-glandular injection, on account of the intimate
connection between the skin and lymphatics. Immunity is likely to be stepped up
and prolonged if animal is given a suitable sensitizing dose 6 days prior to
immunising dose. (H.K.I.).
Protein as an Indicator of Pasture Forage Digestibility. R. M. FORBES (1950).
J. Anim Sci. 9, 231
I N the present article an attempt has been made to evolve method of calculating
the dry matter digestibility of forage from the protein content and the predicted
protein digestibility. Data from digestion trials with steers and sheep were used
for the purpose of these calculations. The digestibilities calculated by the protein
digestibility method were compared with similar data obtained by conventional and
lignin ratio methods. It was observed that the protein digestibility method gave
average results similar to those obtained by the other two methods, generally.
However, the slope of the regression lines relating dry matter digestibility to lignin
content of the forage was less when the protein digestibility method was used than
when either of the other two methods was used. The difference in slopes is, however,
statistically significant in case of lamb trials only. A consideration of the data in-
dicates that although the calculation of dry matter digestibility from predicted
protein digestibility fails to attain the expected accuracy in all cases, the method
may be used with a satisfactory degree of accuracy in case of grazing steers. (B.S.)
Bovine Mastitis. A Comparison of the Value of Diagnostic Methods. CHU, S. J.
(1949). J. Comp. Path Therap., 59, 81-90
A STUDY of 87 quarters from 26 cows affected with mastitis was made with a view
to correlate the results given by five indirect tests and the culture test of milk
samples with those given by the cultural and histopathological examination of the
udder tissue from which the milk was collected.
The accuracy of the indirect tests e.g. chloride test, catalase test, whiteside test,
bromothymol blue test and the total cell count, when judged on the basis of culture
test was 50.6, 46.0, 49.4, 55.2 and 45.0 per cent respectively, each test showing a high
percentage of false positives. When assessed upon histopathological examination
of the udder it was 87, 92, 82, 43.6 and 100 per cent respectively. The accuracy of
the culture test by a similar comparison with the histopathological examination was