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ABSTRACTS
The organisms are considered to be the terminal cause of the pneumonia. The
presence of a primary filterable virus is suspected but its identity has yet to be deter-
mined. The natural mode of infection is unknown. It is suggested that changes in
environment and weather conditions may precipitate outbreaks. [S. G.]
Some aspects of feeding in relation to livestock diseases. W. C. MILLER (1938).
Vet. Rec. 50, No. 33, 1041-1047.
THE author presented this paper at a meeting of the Royal Counties Division, N.
W. M. A. held at Oxford and discussed in general terms, on a broad basis, some
aspects of faulty feeding responsible for certain livestock diseases, without, however,
entering into details of a specific deficiency caused by a particular substance.
The author remarked that the farm animals in Great Britain have been gradually
changed by the activities of the breeders and feeders into ' creatures' which require
a very different type of dietary intake from their ancestors. The modern dairy
cow must eat and deal with a far heavier and richer diet than the wild cow, her
ancestor ; a level of feeding which might readily kill a cow of African indigenous breed,
can be very well tolerated by a cow of a modern British dairy breed.
Referring to some conditions which are typically regarded as being due to errors
in feeding, the author divided the consideration of the subject into different arbitrary
categories.
(a) Overfeeding with balanced foods.—Among conditions which fall into this
category, but which may be brought about by other associated factors (such as lack
of exercise or work) are :—various forms of colic, myohaemoglobinuria, lymphangitis
(non-specific) urticaria, some forms of male and female sterility or infertility and
diffuse lipomatosis.
(b) Overfeeding with one or more food principles.—When the rations are in an
unbalanced condition, particularly when there is excess of one ingredient, the digestion
and assimilation of the whole of the food may be readily upset and illness may
follow. For instance (i) excess of fats causes ketonaemia, acetonaemia, acetonuria
and acidosis; (ii) excess of proteins causes acidosis, and pregnancy toxaemia.
Besides this, faeces assume an offensive odour, urine becomes thick and more
viscid than normal, of high specific gravity ; and in pronounced cases of some duration,
the skin shows eruption or scaliness, appetite is impaired or lost, the breath may have
a strong unusual taint and there may be some oedema in dependant parts of the body.
(c) Underfeeding and deficiencies in diet.—Underfeeding
in general or feeding
on theoretically adequate rations which have been stored for sometime and which have
suffered deterioration due to oxidation and fermentative changes, besides offering non-
nutritious herbage from rough grazings leads the animals to suffer from chronic
constipation, hard, dry and staring coat, with sunken eyes and little or no flesh. It is
animals of this class which are prone to suffer from parasitic invasion, hoose and liver
flukes etc. if opportunity for infestation arises. The inadequacy of calcium, phosphorus
and magnesium intakes during the growing stages may be responsible for making
these animals susceptible to diseases, although it has not been clearly shown that
milk fever can be prevented by feeding adequate minerals and catalysts to the calves
and heifers in a herd which are destined to become heavy milking cows in later life.