314 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, IV
domestic animals should be among a country's most valuable assets, and that
every native who wishes to possess stock is entitled to attempt to do so, also that
the special importance which pastoral tribes attach to cattle must be respected ;
on the other hand, there is the realization that the natives ' present methods of
asserting their rights and privileges are prejudicial to general welfare.
A first task of such a department should be a survey of the distribution of stock.
When this was done in Tanganyika Territory, a very unsatisfactory state of affairs
was revealed.
No less than two-thirds of the Territory were found to be tsetse-infested and
therefore free from cattle, and carrying only a sparse population of smaller stock.
Two-ninths, although tsetse-free, carried a sparse animal population insufficient
for the ordinary needs of the natives of the same areas ; and the remaining one-
ninth was stocked to saturation.
The next step was to explain this distribution. The reason why the large
tsetse-infested area is nearly free from stock is obvious but the explanation of the
distribution of domestic animals on the fly-free areas was obtained only after some
years of study, and is briefly as follows :
The two-ninths of understocked country are for the most part high-lands with
granitic soils and a rainfall exceeding 30 in. Possibly the climax vegetation of
such country is evergreen forest, but frequently recurrent fires now permit only
a sub-climax of grassland or open deciduous savannah. The soils, too are leached
and lateritic. The tall pyrophytic grasses which grow under these conditions
furnish very great quantities of potential cattle-food so long as they are immature ;
after maturity they lose almost all nutritive value, so that animals which are fat
at the end of the rainy season lose condition rapidly throughout the cold dry
months which follow. The same conditions of close grass-formation and compara¬
tively cool moist climate are very favourable to the extra-host existence of ticks
and parasitic worms, so that tick-borne diseases, notably East Coast Fever of
cattle, and helminthiases, notably distomiasis of cattle and strongyloses of sheep
and goats, are enzootic. Skin diseases, such as streptothricosis and follicular
mange, affecting all classes of stock, are also prevalent. The net result is heavy
disease infestation in a low nutritional environment; a state of affairs leading
inevitably to small flocks and herds composed of individuals which are heavily
parasitized, frequently stunted, and of low fertility. There is usually a high mor-
tality among young stock, and those which survive do so by virtue of acquired
immunity to enzootic diseases imposed on an inherited high resistance to these
diseases. Few imported animals can survive in such a locality unless they come
from somewhat similar environment elsewhere. A somewhat surprising revela-
tion is that although the cattle of these areas show such high resistance to local
diseases, they offer little resistance to any unusual epizootic which may arise ;
for example, an uncontrolled outbreak of rinderpest is usually disastrous in its
consequences, and may completely exterminate a local cattle population.