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THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [I, III
to base even an opinion as to whether or not deficiency of some of these may affect milk yield or
health.
The making good of gross mineral deficiencies in the rations of cows, by the addition of mineral
salts, involves no great difficulty. It is a simple matter to compute the approximate mineral
content of the ration from available analytical data, A comparison of the percentages of each of
the minerals present and of the ratios of these amounts to the percentage amount of protein or to the
energy value of the rations, with those found in either milk or good pasture, will show whether,
and roughly, to what extent, any of the minerals is deficient. Calcium and phosphorus can be
supplied in the form of bonemeal or ground limestone; sodium and chlorine as common salt.
So far as we know the only other mineral which may be deficient in certain rations or in certain
areas is iodine, which may be supplied as potassium iodide.
It is obvious that no mineral mixture of constant composition is adapted for use with all kinds
of rations. Further, the substances dealt with are easily obtainable, so that any intelligent person
can make cheaply the mineral mixture required for whatever ration is being used.
The addition of inorganic salts to deficient rations is, of course, only a second best method of
ensuring that the cow shall have a sufficient supply of all that is necessary. A slower, but
certainly more efficient, method is to grade up pastures and crops so that their mineral composition
more and more closely resembles that of milk, and thus provide also for indoor feeding a roughage
of high mineral content. Even then the selection of concentrates and other indoor feeds must
aim at securing the highest possible mineral content, so that the amounts supplied in a composite
ration may be in excess of that found in good pasture.
The viability of B. Tuberculosis (Bovinus) on pasture land, in stored faeces and
in liquid manure.
The following conclusions were arrived at as a result of a series of experiments carried out in
England by Messrs. R. Stenhouse Williams and W. A. Hoy, and published in the Journal of
Hygiene, Vol. XXX, No. 4, 14th November, 1930, viz :—
1. Under ordinary conditions in the south of England B. tuberculosis may remain alive and
virulent in cow's faeces exposed on pasture land for at least 5 months during the winter, for 2
months during spring and for 4 months during autumn. In summer no living organisms were
demonstrated after 2 months.
2. Under special conditions, e.g. protection from direct sunlight, the survival period may be
4 months during summer. In autumn faeces protected from earthworms, etc., yielded bacilli after
6 months.
3. Living and virulent B. tuberculosis were found after 12 months' storage in the naturally
infected faeces, and for a period of at least 2 years in the artificially infected faeces.
4. Living and virulent B. tuberculosis were found in stored liquid manure at least 4 months after
infection. During this time a gradual diminution of the virulence of the material was observed.
The Differentiation of the species of the Genus Brucella.—I. FOREST HUDDLESON.
(From Agricultural Experiment Station, Michigan State College of Agriculture and
Applied Science, Technical Bulletin No. 100, August 1929.)
SUMMARY AND CONCLUSIONS.
A total of 310 strains of the genus Brucella have been studied to determine the accuracy of a
rapid and simple method for distinguishing the main species to which they belong.