Abstract:
1. A form of paralysis or paresis prevalent in some parts of the Union
in young pigs is described. There was evidence already that it was due to a deficient diet.
2. Experiments were carried out to establish the cause of this disease
more definitely by feeding to young pigs rations low in vitamin A, in
calcium or both.
3. The pigs deficient in vitamin A developed symptoms which in the
earlier stages at any rate correspond with those seen in the natural disease.
An account of the symptoms and pathological changes noted in this artificial
avitaminosis is given.
4. The pigs on a combined vitamin A and Ca deficient diet developed
such a softening of the skeleton that within 80 days three out of four fractured
their spine and had to be destroyed. Other pigs started on the same
ration when somewhat older, and which presumably, therefore, had a greater
calcium (+ vitamin A) reserve in their body, did not develop such extreme
lesions.
5. Gilts on a vitamin A deficient diet showed irregularity in the oestrous
cycle. Oestrus occurred more frequently and persisted for abnormally long
periods.
6. A ration of equal parts by weight of skim milk and white maize is
physiologically complete for growth in pigs except that it is low in calcium
and in vitamin A.
The incorporation of 2 per cent. bonemeal and 10 per cent. lucerne
meal in such a diet or the substitution of yellow maize and bone meal for
white maize resulted in normal growth and good health in pigs. Where
green feed or other cheap sources of vitamin A are not available in adequate
quantities, such a supplementation should prevent all tendency to paralysis
and poor growth.
7. Cod liver oil administered to animals even in advanced stages of the
deficiency effected rapid and striking improvement in health. Some of the
lesions, however, could not be cured completely, e.g., bad cases of scoliosis
and blindness.
