NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
REGINALD
LOVELL
447
given quantity of suspension or, in the case of a toxoid, as the
number of doses estimated by a precipitation test, it is essential to test it by
animal experimentation.
One way is to immunize a series of animals—usually small laboratory
animals—and after a certain period, subject these and a number of control
animals to an injection of the living organizm or may be its toxin. The po-
tency of the product may be ascertained by a comparison between the two
groups of animals taking either death or a particular reaction as the end-point.
Another method, probably more efficient, possibly more drastic and
certainly nearer to natural circumstances is to immunize a number of experi-
mental animals and subject them to a disease environment. This has been
done with mice [Greenwood et al., 1936] whereby immunized animals are put
into cages in which an epidemic is occurring. The length of life of the
immunized mice compared with that of the non-immunized will give an indica-
tion of the value of the particular vaccine. It is of course obvious that this
technique is limited to diseases which occur readily and are capable of spread
in the experimental animal. It may be used, however, with prophylactics
prepared from certain Salmonella, Pasteurella and the virus of ectromelia. A
criticism which has been made against BCG is that, although knowledge is
available as to the fate of immunized calves injected artificially with living
tubercle bacilli some months later, there is as yet not a sufficient amount of
clear-cut evidence of the fate of immunized calves which are in an environment
where they are constantly and successively exposed to living tubercle bacilli.
The third and most effective way of testing prophylactics is only available
with the cooperation of the practitioner and stock-owner. Careful and critical
observation in field tests is essential before a final opinion can be given. As
immunization is only one factor and in this case the factor to be assessed—in
the control of disease, it is essential that a sufficient number of animals, similar
in all other respects, be left as controls. It is only by comparison of the
mortality or morbidity in such groups of animals that a particular prophylactic
can be valued. The preliminary work is done in the laboratory, but of
necessity in laboratory animals and possibly in a few of the larger animals, and
the final test is a field one. Cooperation of such a nature between the laboratory
worker, the practitioner and the stock-owner is therefore essential to progress
and increased control over the diseases of animals.
REFERENCES.
Avery, O. T. and Goebel, W. F. (1933). J. Exp. Med. 58, 731
Boivin, A. and Mesrobeanu, L. (1935). Rev. Immunol. 1, 553
—(1936).
Ibid. 2. 113
Bulloch, W. (1938). The History of Bacteriology. Oxf. Univ. Press
Cruickshank, J. C. and Freeman, G. G. (1937). Lancet. 4 Sept., 567
Dudley, S. F., May, P. M. and O'Flynn, J. A. (1934). Spec. Rept. Ser.Med. Res. Comm.
195
448 Immunization of Animals Against Bacterical Disease
Glenny, A. T., Pope, C. G., Waddington, H. and Wallace, U. (1926). J. Path. Bact.
29, 31
Goebel, W. F. (1939). Nature, Lond., 14 Jan., 77
Greenwood, M., Hill, A. B., Topley, W. W. C., and Wilson, J. (1936), Spec. Rept. Ser.
Med. Res. Comm. 209
Lovell, R. 1937. F. Path. Bact. 45, 339
Minett, F. C. (1937), .Vet. Rec. 49, 179
Nattan-Larrier, L., Ramon, G., and Grasset, E. (1927). Ann. Inst. Pasteur 41, 848
Raistrick, H., and Topley, W. W. C. (1934). Brit. F. Exp. Path. 15, 113
Ramon, G., and Descombey, P. (1927). Ann. Inst. Pasteur 41, 834
Stamp, T. C. and Hendry, E. B. (1937). Lancet. 30 Jan., 257
Tomcsik, J. and Ivanovics, G. (1936). Int. Congr. Microbiol, 2, 358
Topley, W. W. C., Raistrick, H., Wilson, J. Stacey, M., Challinor, S. W. and Clark,
R. O. J. (1937). Lancet. 30 Jan., 252
Vallery-Radot, R. (1919). The Life of Pasteur. Eng. Trans. R. L. Devonshire.
Constable, Lond.
Waldmann, O. (1938). Dtsch. tier ar ztl. Wschr. 46, 569.
NATIONAL NUTRITION CONFERENCE*
VETERINARY ASPECTS OF NATIONAL NUTRITION
BY
WM. C. MILLER, M.R.C.V.S, F.R.S.E.
Royal Veterinary College, London
(Reprinted from the Veterinary Record, Vol. 51, No. 23, June 10, 1939)
I WOULD like in just a word to compliment the British Medical Asso-
ciation, and the Organization Committee of this Conference, for the great
wisdom of their decision to hold a series of meetings dealing with the much
neglected subject of nutrition. I would also thank them for the honour they
have done me in extending an invitation to speak.
INTRODUCTORY
In all probability, the first quarter of this century will be registered in
the archives of history as a period when the major attention was devoted to
the elucidation of disease causation upon a purely bacteriological basis.
Subsequently, and to some extent concurrently, we have seen a phase of
intensive investigation of diseases of plants, animals and men due to viruses :
a phase, the end of which has not yet been reached. Slowly during this time
it has become very clear that neither the bacterium nor the virus is the complete
answer to the question, ' What causes disease?' Minerals have enjoyed
a phase of popularity ; vitamins are fashionable, but though both are important,
neither of them is more than one factor in the cause of disease.
I think we may reasonably assume that a further contribution to the
solution of the general problem is being made and will continue
to be made by intensive study of the nutrition of the organizm,
viewed as a whole. Considerable progress is being made on the frontiers of
this newer knowledge, and although the horizons are as yet by no means
clear, various avenues are being opened up to give a far more lucid conception
of the situation. In the forefront of this endeavour there is a body of aca-
demic research workers in the realms of pure science—chemistry, bio-chemistry,
bio-physics, physiology and so on. Behind them are those who direct and
carry out applied research, whether to man, animals, or plants, and later
there are those whose task it is to effect consolidation by the organization,
control, and application of knowledge to the masses and to the individual.
* Conference summoned by the British Medical Association, held at the B. M. A.
House, London, on 27, 28 and 29 April, 1939.
( 449 )
450
National Nutrition Conference
Neither in human nor in veterinary medicine is the organisation perfect
but the structure is already loosely something along these lines.
It is my duty to outline (and it must be an outline only) the field of
activity of the veterinarian in relation to the health of the people, and to sug-
gest for your consideration what further functions he, whether independently
or as an integral unit in a coordinated plan, might usefully perform.
The activities of the veterinarian as a factor in human nutrition schemes
fall into five main categories.
ADMINISTRATIVE CONTROL OF ANIMAL DISEASE
The health of the public in Britiain is safeguarded to a very consider-
able extent by the control of certain diseases of animals exercised by the
Veterinary Staff of the Animal Health Division of the Ministry of Agriculture
and Fisheries, together with members of panels of part-time officers chosen
from among veterinary practitioners who perform local duties under the direc-
tion of an area official. This organization has recently been reconstituted
into a unified veterinary service.
It is well known to you that it is only during comparatively recent years
that a concerted effort has been made to reduce the incidence of certain
major diseases among animals which may be contracted by the human being,
and although much progress has been made, there is still much to do. By
the operation of the Agriculture Act a beginning has been made to eradicate
tuberculosis from dairy and other cattle stocks. Some 5,000 herds are already
attested free from tuberculosis and many more are in active process of being
cleared. Although the health of the animals themselves is the primary consi-
deration, 'pari passu a reduction in the amount of tuberculosis infected milk
available to the consumer will follow, and a reduction in human tuberculosis
of bovine origin will result. I would wish here to disarm possible criticism
by stating that while I fully appreciate and agree with the logic of the argu-
ments in favour of pasteurization of all milk for human consumption, it would
be deplorable if pasteurisation should ever become a substitute policy for
disease eradication. The two aspects are each of primary and should be of
complementary importance.
From the aspect of livestock health, it is now well authenticated that
in the tubercle-free herd the incidence of intercurrent and sporadic diseases
and illnesses has markedly diminished. Further, the efficiency of the herd
as a milk producing unit is increased by approximately 25 per cent. This
means that 20 cows free from tuberculosis can constitute a herd equal in
efficiency to one of 25 cows which contains some reactors. The eradication
of bovine tuberculosis would enable approximately 200 million gallons of
extra milk to be produced annually without increasing the total number of cows
in the country above present levels. Put in another way, there would be avail-
able about two oz. more milk per head of the whole population daily without
any extra cost of production.
WM. C.
MILLER
451
Since the same system of eradicating tuberculosis is now being extended
to beef breeding herds, the butcher buying from such a tubercle-free herd
has no risks to run of condemnation of carcase meat from tuberculosis. I
do not know the annual loss to the country occassioned by condemnation
for tuberculosis, but it is tremendous. Some of the animal diseases, apart
from tuberculosis, which can cause illness in man include brucellosis, mastitis,
some forms of mange and ringworm, and of lesser frequence, anthrax,
psittacosis, salmonellosis, glanders and rabies. Fortunately, glanders and
rabies, owing to the vigorous policy pursued in past years, are no longer
indigenous in Britain.
Apart from the direct protection of public health afforded by this type of
control, however, the veterinary staff of the Ministry of Agriculture is res-
ponsible for indirect conservation of animal health in that control is exercised
over such diseases as swine fever, foot-and-mouth disease, sheep scab, sheep
pox, etc. The net result is that a quantity of sound animal food products—
meat, milk and eggs—is made available for human food purposes which
might otherwise be lost or at best be of inferior quality. Such activity helps
to maintain supplies and to stabilize prices. The shortage of meat and milk
suffered by European countries during the extensive outbreaks of foot-and-
mouth disease in 1937-38 and even at present, gives some basis for comparison,
and indicates what conditions might be like in Britain without such control.
Professor Müssemeier recently reported that, in spite of preventive measures,
the loss from foot-and-mouth disease in Germany during the recent extensive
outbreak is not less than 1,000 million marks (£83,000,000).
FOOD INSPECTION SERVICES
Britain even to-day lags behind many foreign countries in the organiza-
tion of its food inspection services. The antiquated system whereby the
medical officer of health or the sanitary inspector (neither of whom has any
specialized knowledge of animal health or disease), is primarily responsible
for the inspection and seizure of unsound or diseased animal food products,
and what is far more important, for passing meat as fit for human consumption,
still operates in many parts of England, while in many of the smaller towns and
villages there is still much meat prepared and sold for human consumption
which is not examined by any one.
Where, however, efficient veterinary inspection is carried out a barrier
is created to protect the public from the effects of consuming diseased or
unsound animal food products. In certain large cities, not only meat and
milk, but fish, preserved food, fruit, vegetables and so on, come under the
same scrutiny. Harmful foods are seized and safely destroyed, while a
constant watch is maintained upon the general quality and wholesomeness of
the food sold for human consumption. I need not enlarge further upon the
importance of this work to the supply of wholesome and safe foods for public
consumption : it is sufficiently obvious. The need for the extension of these
services in the public interest is equally obvious.
Q
452
National Nutrition Conference
CONTROL AND TREATMENT OF SPORADIC AND OTHER ANIMAL DISEASE UPON
PRODUCERS PREMISES
The functions of the local veterinary practitioner, in so far as treatment
of disease amongst food producing animals is concerned, are similarly well
known. The field is a wide one and under the present system it is impossible
to estimate the full importance of this work. The Loveday Committee
recently estimated that some £19,000,000 are lost annually to livestock owners,
and so to agriculture, on account of animal disease. The potential loss pre-
vented by the activities of local practitioners is probably at least another
£19,000,000 : this assumes only a 50 per cent efficiency figure in the treatment
of animal disease. (I feel sure that many of my colleagues would take me to
task for accusing them of only 50 per cent efficiency, and the saving they
effect may well be greater).
By securing the confidence of his clients, the veterinary practitioner in
breeding and rearing districts plays an increasing part in securing a better,
healthier, and more efficient livestock population. He is in a position to act
as guide, philosopher, and friend to those who seek his help in matters of
animal management, breeding, feeding and along other lines not directly
concerned with animal disease. In this way he plays a not inconsiderable
part in ensuring a healthier human population, especially in so far as animal
foods are concerned. He is capable of contributing a far greater service when
called upon to do so.
COLONIAL WORK
I would like to summarize very briefly the part played in many of the
colonies by the veterinary officer, since the work there not only upon disease
control but also upon animal husbandry, and all that this entails, has an
important bearing upon nutrition and well-being of the native races, upon the
industrial efficiency of the colony and therefore indirectly upon the population
of Britain so far as it is affected by colonial enterprise, and resulting national
wealth, employment, trade, etc.
The work has gradually developed from the control of the major
devastating epizoötics which formerly brought famine and havoc in their
trail, through the stages of investigation and control of more local diseases,
until now progressive colonies are pursuing an active policy of improvement
of livestock by the encouragement of proper systems of grazing, conservation
of forage and other crops for use during droughts and periods of shortage,
improved methods of management, breed selection, use of imported sires for
grading up scrub stock, and better processing of meat and milk products.
The whole of this work must be under constant expert supervision so that the
reactions of stock to differing environmental conditions can be watched and
any necessary measures immediately taken, and so that epizootics, which are
still liable to recrudesce, may be controlled and eradicated promptly and
efficiently. The veterinary officer is the indispensible keystone to the success
WM. C.
MILLER
453
of this work, and though cooperation with medical, educational, agricultural
and administrative departments, is eminently desirable, no other service can
play such an impressive and important function.
The above policy actively pursued is calculated to make possible a higher
standard of living for the native. He pays his tax, purchases implements,
grows better garden produce ; by using more animal manure he increases soil
fertility, and is thereby encouraged to adopt settled instead of nomadic farm-
ing systems, is better nourished, happy and contented; these factors acting
together provide a powerful insurance against social unrest.
POSITIVE POLICY OF DISEASE PREVENTION
Many of the veterinary functions outlined earlier are best described as
being of a negative nature, in that each is concerned with the limitation of
disease in one form or another after it has already occurred. There is, how-
ever, a far more important part to be played by those with a veterinary train-
ing and an adequate knowledge of livestock. There is the positive policy,
far more comprehensive and important, of disease prevention. The study of
health, as an end in itself and of the measures and methods to achieve and
maintain health must be carried on as a complementary but fundamental
study by those whose work may be mainly concerned with disease.
The training of the veterinarian has until recent years been along lines
concerned wholly or mainly with the diseases of animals. Doubtless this
type of educational structure was adequate in the earlier and more spacious
years of this and a former century. The power of the infective agent and its
action upon the tissues were regarded as all important. The farmer was
content so long as his animals could be treated when suffering from this or that
active diseased process. To a large extent among the older members of the
community this view is perhaps still held. There is, however, an acute
realization both by farmers and veterinarians that more is needed.
Eminent men in medicine, whose names are familiar to you all, biologists,
sociologists, and others, are doing much to make the public aware that mere
freedom from obvious disease is not enough. And so during recent years,
revolutionary developments relating to human health have been seen—
physical fitness schemes, ante-natal clinics, advisory centres, milk for school
children, and various other mechanisms which all aim at increasing human
health and the enjoyment of life.
Among primary producers of animal food-stuffs a certain amount of
change has similarly begun. The functions of the veterinarian are slowly
extending to embrace advice on the details of housing, breeding, rearing,
feeding, exercise, and general and particular methods of management in stud,
herd and flock.
It is not perhaps desirable, even if it were possible, to discuss these matters
in detail, but it is possible to state quite categorically that the veterinarian
who does not have to spend a very considerable proportion of his daily working
WM. C.
MILLER
457
foolish but very common. Many old-established pastures are long overdue
for ploughing, cropping for one or two years, and re-sowing with proper grass
seed strains and mixtures.
Training and Education.—If the veterinarian is to fulfil an adequate
function in the structure of modern social organization and play the part which
his special training and knowledge of the animal in health and disease fits him
to carry out, the change in approach which has already occurred should be
further emphasized and greatly encouraged at colleges and teaching insti-
tutions. For too long the veterinary profession has somewhat blindly modelled
its courses of study upon those of the profession of human medicine. Human
medical schools have been established in the centres of dense human popula-
tion ; veterinary schools are no longer in the centres of dense animal popula-
tion. Field stations are urgently needed so that fuller immediate contact
between the student, the soil and the farm animal can be achieved. The
bias towards the horse (and more recently to dogs and cats) should be changed,
and the food-producing animals should receive the major amount of atten-
tion. A detailed intensive study of health should run concurrently with the
study of disease, and great emphasis should be laid upon prevention.
The British Administration, both Central and Local, should utilize
veterinary services—whether of whole-time or of part-time officers—to the
fullest capacity. Most continental countries, in particular Denmark,
Germany, Italy, and Russia, some of which have not the natural and special
advantages we possess in Britian, are far ahead of us in their veterinary
control of animal health and disease, while in the U.S.A. the veterinarian
plays an even greater part than in Europe. In many of the Dominions and
self-governing dependencies and in some of the colonies veterinary services
are employed far more usefully and with greater advantage to the community.
It is hardly necessary to indicate that should a state of emergency arise
it may be necessary to contemplate malicious spread of serious disease among
food-producing animals and measures for their control and the protection of
the public may become more necessary than they are when no such emergency
exists.
I have attempted to give an outline of some of the ways in which veteri-
nary members of the community are contributing and might be called upon
further to contribute towards an improvement in the levels of nutrition and so
in the health of the general public. The various aspects dealt with have
compelled me to be perhaps somewhat sectional and parochial, but I trust I
have not conveyed an impression that the major and primary aspect of the
urgent need for a general improvement in the health of crops, animals and
mankind has been forgotten.
460
ABSTRACTS
The following requirements of animals in relation to reproduction have been dis-
cussed.
(1) ENERGY REQUIREMENTS
The additional requirements for pregnancy are trivial in the early stages of gestation
but a 15 per cent addition to the basic maintenance is required in the closing weeks of
the gestation.
(2) PROTEIN REQUIREMENTS
In quickly growing animals, i.e., sow, the additional requirement for food protein
imposed by pregnancy is no less than 32 per cent on the average of the whole period and
70 per cent in the closing stage of gestation, but if the rate of development is slower as
in the case of the cow, the maintenance requirement may be increased during gestation
by an average of 17 per cent over the whole period or 40 per cent in the closing stage.
(3) VITAMIN REQUIREMENTS
The author considers that only for vitamins A and E there seems to be a clear case for
postulating that the maternal diet must include extra amounts to cover any specific re-
quirements for reproduction. The simplest practical safeguard against deficiency of
vitamin A lies in the supply of leafy green-stuff. Where this is not available the inclu-
sion of yellow maize in the ration will be helpful.
Although the basic need of vitamin E for reproductive efficiency has been demons-
trated, there is little evidence as yet that breeding trouble due to deficiency of this factor
are met with more than rarely in farm animals. Nor indeed, is it to be expected that
this type of trouble would be often met with in view of the supply of the vitamin in green-
stuffs or the germ of cereal grains.
The specific requirement of vitamin D for reproduction would seem probable, but
conclusive evidence has not yet been obtained especially as regards farm animals.
(4) MINERAL REQUIREMENTS
Taking a minimum requirement of 0.10 per cent each of calcium and phosphorus
in the dry matter of the food for the ' empty ' dry cow, an increase by 0.07 per cent for
dry in calf cow and a further addition of 0.07 per cent for each gallon of milk has been
recommended.
The other minerals that may be required in breeding practice are iron, iodine and
salt, but nothing has been suggested with regard to their quantitative requirements.
(N.D.K.).
Rinderpest: The immunizing value of frozen desiccated goat spleen, PFAFF,
G. (1938), J. S. Afr. Vet. Med. Assn., 9, (4) 188.9
THE author describes the preparation of the vaccine by killing infected goats on the
fourth day, several spleens are removed asceptically and pooled so as to have a fair
concentration of virus. They are then ground in a Latapie pulper, dried in vacuo over
calcium chloride and stored at 42°F.