Download Aspects of Animal Health in Organic Livestock Production

Aspects of Animal Health in
Organic Livestock Production
Douglas Gray
Veterinary Science Division
Aberdeen
Background
The number of conventional livestock farmers
converting to organic production has increased
dramatically in recent years. The pressures to
change are mainly market led with actual and
projected sales of organic produce rising
steadily. The reasons for this include negative
consumer perceptions of certain aspects of
conventional intensive animal production
systems. Unacceptable welfare conditions, drug
residues and alleged transfer of antibiotic
resistance from animal to human bacterial
infections have all resulted in the consumer
seeking “healthy” and ethically acceptable
food, including organic products. From the
farmer’s perspective, significant reductions in
net farm income, particularly in hill and upland
enterprises have encouraged farmers to look at
products which have added value and which
have some system of quality assurance.
Organic production satisfies both of these
requirements but the management skills
involved in developing and maintaining a
successful organic animal enterprise are
considerable. Safeguarding animal health and
welfare under organic rules is fundamental.
Organic Philosophy
Organic farming is a system which minimises
the use of non renewable external inputs of
agri-chemicals (including veterinary medicines)
and fertilisers. It is based on a closed,
rotational system in which animals have a
central role in the grass/clover leys which
comprise the fertility building phase of the crop
rotations. They provide the organic manure
needed for transfer of plant nutrients around the
farm. In addition, the maintenance of good
animal health and welfare is an important
principle of organic farming. In organic
systems, animal health is not seen simply as the
absence of disease; it is seen as a positive
characteristic which is to be achieved through
the application of biological and animal
husbandry principles, rather than reliance on
the routine use of conventional veterinary
medicines. Where medicines are required, the
use of complementary methods both for
prevention and treatment of disease is
encouraged. This aspect is one which causes
most difficulty for many conventionally trained
veterinary surgeons in the UK. It must be
emphasised however that good animal health
and welfare are integral to the philosophy of
organic production. Any practice which
compromises this will not be acceptable to the
certification bodies responsible for enforcing
organic standards.
Organic Livestock Standards
Within the European Union, Organic standards
are laid down in EU Regulation 2092/91 and
are interpreted and enforced in the UK by
UKROFS (The United Kingdom Register of
Organic Food Standards). Individual “sector
bodies” are responsible for inspecting and
certifying producers, processors and retailers of
organic produce and for ensuring that they
comply with the sector body standards. These
must at least conform to UKROFS standards
although some sector bodies apply more
stringent rules.
In relation to animal production the standards
have only recently become standardised across
Europe. EU Regulation 1804/99 came into
effect in August 2000. This specifies the
requirements for selecting, breeding, housing,
feeding and husbandry of animals and the
conditions for conversion of conventionally
reared animals to organic.The detail of the
standards will be found in the UKROFS
Standards Handbook or the standards produced
by individual sector bodies.
In relation to animal health and welfare, the
application of principles of breed selection,
good management, nutrition and husbandry,
appropriate to the animal species forms the
basis of disease prevention and good animal
welfare.
When clinical disease does occur, treatment of
individual animals is essential. The new
Regulation for the first time specifies that
where treatment of clinically ill animals is
necessary, complementary methods such as
homeopathy should be used in preference to
conventional veterinary medicines. This has the
proviso that the medicine used should be
efficacious for the condition being treated. The
use of conventional medicines may affect the
organic status of the animal and its products
and the withdrawal period for drugs is at least
twice that specified in the data sheet for that
product. The Regulation also prohibits the
prophylactic use of conventional medicines
(such as dry cow therapy for mastitis).
Although such routine use of medicines is not
permitted, where a proven disease problem
which cannot otherwise be prevented has arisen
on an organic unit, conventional prophylactic
vaccinations or other treatments may be
permitted. This must be as a result of
consultation with the sector body responsible
for certifying the individual organic unit.
Normally approval will only be given once
verifiable evidence of the problem has been
submitted and the sector body is satisfied that
alternative methods are not appropriate. Such
approval should be sought as part of the
livestock conversion plan.
Conversion to Organic Status
During the process of converting from
conventional to organic production a plan must
be implemented which addresses the animal
health and welfare problems of the individual
unit. This plan should be drawn up by the
farmer and agreed with the relevant sector body
before the start of the conversion period.
Technical assistance should be sought from the
veterinary surgeon who normally provides
animal health advice for the unit and from other
advisers as required. Further information on
converting to organic production can be found
in SAC Technical Note T451.
Methods of Disease Control
As previously stated, the health of organic
livestock is to be safeguarded using the
principles of preventive husbandry. These
principles
are equally
applicable
to
conventional livestock systems. The organic
system if designed and applied properly should
promote the animal`s immune system, reduce
exposure to infectious agents and reduce the
chances of nutritional or metabolic diseases .
General Methods for Livestock Enterprises
The principles of disease prevention are based
on the following aims:
A. Infectious Disease:
1. Reduce Exposure to Infectious Agents:
Closed flocks and herds: Biosecurity
Create disease free populations: High
health status herds/Health schemes. (eg
EAE, MV, BVD, IBR, EP)
Reduced stocking density. (pneumonia)
Hygiene: Navel dressing. (Navel ill, scours).
Milking routine. (Mastitis). Disinfection.
Remove/Separate Carrier Animals:
(immune v susceptible). Avoid mixed ages
in buildings. Provide sick bays. Quarantine.
Grazing management: Clean grazing
systems. (Parasitic diseases).
Mixed species farming: Rotations. Some
disease agents are specific to a livestock
Species (eg IBR, parasitic worms).
2. Stimulate Natural Immunity.
Colostrum management. (Passive protection
- scours).
Adequate nutrition: Energy, protein,
minerals, trace elements and vitamins.
Natural exposure to disease agents at low
level of challenge. Stocking density. Grazing
management
Reduce stress. Provide shelter.
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3. Select Animals with Innate Resistance:
Use breeds appropriate to conditions and
available nutrition.
Genetic resistance. Use breed and
individual animal variation.
B. Nutritional Deficiencies and Metabolic
Disease:
1. Provide adequate nutrition:
Energy, Protein, Minerals, Vitamins.
Nutrition appropriate to species, age,
production stage and level of production.
2. Reduce stress: Avoid sudden changes in
feeding, housing, movements.
3. Provide adequate and appropriate housing
or shelter as required.
4. Select animals appropriate to production
requirements. Breed characteristics.
5. Soil/Plant/Animal Interactions:
Minerals. Trace elements.
Specific Methods for Organic Enterprises
The following are some examples of the general
methods shown above.
A. Infectious or Parasitic Diseases:
Enzootic Abortion of Ewes:
Closed flocks or purchase EAE
Accredited female replacements.
Enzootic Pneumonia of Pigs:
Health Schemes. High health status.
IBR/BVD/Leptospirosis/Johnes in Cattle:
Purchase from known sources.
Health schemes.
Maedi visna/CAE in sheep/goats:
Quarantine and test on purchase.
Purchase Accredited animals.
Parasitic Gastroenteritis of Ruminants:
Clean grazing systems (annual cattle,
sheep, crop rotations).
Alternate grazing systems eg annual
rotation with sheep/cattle.
Mixed grazing eg cattle/sheep.
Strategic grazing eg clean pasture for
weaned lambs. (reseeds or silage
aftermath).
Use older immune animals to “clean”
pastures.(eg suckler cows and calves).
Reduce stocking density.
Scour and Navel Ill in Young Animals:
Adequate maternal nutrition.
Outdoor calving and lambing.
Hygiene at birth and first few days.
Navel treatment.
Adequate colostrum intake in first four
hours.
Adequate pre weaning nutrition.
Avoid stress at weaning.
Pneumonia in Cattle:
Outwintering where possible.
Avoid simultaneous weaning and
housing.
Avoid stress at housing (transport,
management practices etc.)
Reduce stocking density at housing.
Avoid multi age housing.
Provide well ventilated and drained
housing.
Provide adequate nutrition without
dust.
B. Trace Element Deficiencies at Grass:
Provide mixed species swards eg
clover/ryegrass plus herbs rich in trace
elements (eg chicory, ribwort).
Minimise potash fertiliser inputs.
Complementary Medicines Complementary medicine systems include:
Herbal remedies.
Acupuncture.
Homoeopathy.
Bio-dynamic techniques.
There is an increasing interest in such methods
in the human medicine field where practitioners
specialising in the techniques are readily
available. In veterinary medicine in Britain
there are few veterinary surgeons with an
interest and even fewer practising. The main
reason for the scepticism expressed by
conventionally trained vets is the lack of
documented scientific evidence to back up the
claims for these methods as applied to animals.
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Anecdotal evidence regarding their efficacy
does exist but very few reports have been
published of properly designed and controlled
trials where these methods have been compared
to conventional treatments or to no treatment.
However, pressure from animal owners may at
least increase the awareness of practising
veterinary surgeons to the existence of such
treatments and an understanding of the theory
behind them. In future it may be necessary to
register homeopathic remedies if a claim for
efficacy is made.
At this stage it must be emphasised that where
individual animals present with clinical disease
then veterinary attention must be sought to
allow appropriate treatment. Where alternative
medicines have been used to prevent disease
without success then again professional advice
should be sought.
Monitoring Animal Health
From the above it can be seen that the
maintenance of good animal health in organic
livestock requires considerable management
skill and stockmanship. Preventive husbandry
programmes are an integral part of the overall
system and must be planned accordingly.
Some conventional animal production systems
have disease problems despite the use of
sophisticated veterinary medicines. It is
unlikely that organic systems will be different.
However the emphasis placed on good animal
health and welfare in organic production makes
it even more important that the system does not
fail. The occurrence of cases of clinical disease
is proof that the system has failed. It is
important where such cases occur that
treatment is carried out promptly and that an
attempt is made to obtain a specific diagnosis.
This will allow changes to be made to the
disease prevention programme on a rational
basis. It is thus important that the health and
wellbeing of animals is checked on a regular
basis by experienced stockpersons.
However it is well known that clinical disease
is only one aspect of the animal welfare costs
of disease processes. Subclinical disease is both
more common and more costly in terms of
production loss and animal welfare. By its
nature subclinical disease is difficult to assess
and requires excellent animal observation skills
and the maintenance and interpretation of
management records. Thus a successful system
requires traditional stockmanship skills as well
as modern management skills and technical
knowledge.
Beyond this, organic farmers should be
encouraged to monitor and record the disease
status of their animals. An examples of this is
carrying out faecal worm egg counts to assess
the effectiveness of a parasite control strategy.
The information may also be used to justify
treatments. Other examples are bacteriology to
determine which mastitis pathogens are present.
On present evidence, the demand for organic
produce including animal protein will continue
to grow. This demand can only be satisfied
from UK sources by the conversion of existing
conventional livestock units to organic. This
conversion
will
require
considerable
management skill , particularly in the areas of
animal health and welfare. This represents a
considerable but worthwhile challenge and
opportunity for farmers, their advisers
(including veterinary surgeons) and research
scientists.
Background Reading
Gray, D. and Hovi, M. (2001) Animal Health
and Welfare on Organic Farms. Organic
Livestock Farming. Chalcome Publications.
UKROFS (1997) Standards for Organic Food
Production, UK Register of Organic Food
Standards, London.
Lampkin, N (1990) Organic Farming, Farming
Press, Ipswich
SAC (1991) A Survey of Organic Livestock
Producers for the Kintail Land Research
Foundation.
Roderick, S, Short, N and Hovi, M (1996)
Organic Livestock Production. Animal Health
and Welfare Research Priorities. The
University of Reading.
Weller, R F and Cooper, A (1996) The health
Status of Dairy Herds Converting From
Conventional to Organic Dairy Farming. IGER
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