R. L. KAURA 369
Crammer [1920] has shown that an absence of vitamin B is associated with a
diminution in the lymphoid tissues, i.e. those parts of the body where lymph
cells are produced, whilst Funk [1914] found that if vitamin B was absent
from the diet, cancer growths slackened and grafts were unsuccessful. Con-
versely Eardman and Haagen [1928] found a great occurrence of tumours in
rats when there was an excess of vitamin B in their diet. Tanniguchi [1928]
found that transplanted cancers (sarcoma) in hens showed least growth on
vitamin B deficient diet, whilst on a vitamin B rich diet the tumours
penetrated irregularly into the tissues. Bayon [1932] has suggested
that deficiency of vitamin C is responsible for the wide spread nature
of this disease where birds are kept intensively and are deprived
of vitamin C containing foods. Plimmer and his associates [1927]
suggest that birds require about 6 per cent of vitamin B in their ration. But,
most of the birds receive a diet containing an excess of vitamin B (present in
the outer layers of grains etc.) and a complete deficiency of vitamin C (present
in cabbage, grasses etc.), which constitute' vitamin imbalance ' and facilitate
the development of this disease in susceptible birds.
The use of rich, forcing mashes containing 18 per cent and more of proteins
of high biological value causing too rapid a growth-rate and the practice of
using in unlimited quantities mashes more especially those containing milk pro-
ducts and yeast which cause an excessive, abnormal, unnecessarily fast rate
of growth, early maturity and premature egg production are also liable to
influence adversely the development of latent fowl paralysis.
3. Management.—It is well known that coccidia and other parasites thrive
best on land which is badly drained, i.e. damp land. Prasites' eggs, coccidia
and disease producing bacteria frequently remain on soils for months and
even years, so that after constantly using such ground for from five to ten
years the land will have become stale and disease stricken and therefore un
favourable for the health of poultry unless it is ploughed or dug up and sown
with a crop, after which it may be considered to be relatively clean. A lack
of insoluble grit is undesirable as it causes an inefficient functioning of the
gizzard. Absence of ' natural' foods during the brooding period, notably
' living ' foods supplying animal proteins or vitamin C is also unfavour
able. With the use of slatted or wire floors which prevent the natural
act of perching it is not unreasonable to presume that nerves of the
legs are devitalized because of improper use, and this may be a
starting point for the disease. Pullet breeding, in-breeding and
the use of battery brooders result in birds which are less resistant to
disease and fowl paralysis is no exception. Flock mating where a large num-
ber of hens are mated to several cocks has the disadvantage that if one of the
stock cockerels is defective in any way, a large proportion of the resulting chicks
of the whole flock may inherit such abnormality. Breeding from birds possess-
ing grey, pearl-like, discoloured eye results in a progeny that may show a
hereditary tendency to fowl paralysis.
SYMPTOMS AND LESIONS
Birds of either sex, more commonly pullets, may be attacked usually
between the ages of 10 weeks and 10 months, although cases have been re-
corded in adult birds sometimes over two years of age, and also in four weeks