ABSTRACTS.
405
examination will often, but not invariably, reveal a beaded condition of the ribs and
enlargement of the parathyroids. The ash percentage of the leg bones is subnormal
and bone and plasma phosphatase values are high. Prevention under commercial
conditions can be done most simply by feeding 0.5—1 per cent of a good grade of cod
liver oil which contains sufficient amount of the anti-rachitic vitamin. The minimum
requirements of vitamin D seem to be linked with the optimum amounts and the
avail bility of calcium and phosphorus in the ration. The term " rickets " has been
used too loosely in experiments with chickens.
Although it is realised that some of the vitamins belonging to the B group, namely,
B 1 and B 2 are definitely required by chickens, there are many problems in this connec-
tion awaiting solution. The necessity for an external supply of vitamin C is also not
yet definitely proved.
The question of the supply of minerals has been studied. Calcium and phosphorus
metabolism is affected by the form in which they are fed as well as by the presence of
vitamin D and of other elements in the ration. Sodium chloride addition seems to be
necessary under certain commercial conditions. The subject of " leg weakness",
which is not a specific symptom of any disease, is discussed under the following head-
ings : (a) due to infestation by intestinal parasites ; (b) due to infection, specific
(fowl paralysis) and non-specific ; (c) due to dietary errors, such as deficiency of vitamin
D or calcium ; excess of magnesium ; " slipped tendon ", " perosis ", " hock disease "
or " deforming leg weakness " which may be due to excessive mineral feeding ; due to
deficiency of vitamin B (polyneutritis) and vitamin A, etc.
The hatchability of eggs is a matter of great importance from the commercial
standpoint. From the experiments reviewed, it seems that under conditions of confine
ment, birds kept for breeding require an animal protein supplement in the ration.
Good grades of milk powder, fish meal and meat meal are very useful in this connec-
tion. Vitamin D deficiency is an important factor in causing poor hatchability, which
can be rectified by the addition of suitable fish liver oils. A good grass range is a factor
of great importance in allowing the birds to supplement their dietary defects. The
proper development of chicken embryos is affected by many things, not the least of
which is the nutrition of the parents. [K. C. S.].
Surla premunition de l'enterite paratuberculeuse desbovides. H. VALLEE,
P. RINJARD, and M. VALLEE, (1934). Rev. Gen. Med. Vet. XLIII, 777.
The article gives an account of the technique of carrying out the so-called premu-
nition as a preventive measure for Johne's disease and gives statistics to support the
conclusion that the adoption of this method of vaccination is attended with no harmful
results and is efficacious.
The vaccination consists in the subcutaneous inoculation of 5 to 10 m. gm. of
unmodified Mycobacterium par tuberculosis bacilli in a non-absorbable vehicle of
vaseline and pulverised sand-stone. This produces a local inflammatory reaction,
which in time becomes a hard, cold, painless swelling. In a healthy animal, this