MAIN
STAKES FOR THE MANAGEMENT AND
UTILIZATION OF
RESIDUES IN ANIMAL PRODUCTION
Teachings and
limits from a method developed in France
Jean-Paul
DUBEUF
INRA-SAD.
F- 20230 San Giuliano
International Goat Association
dubeuf2@orange.fr
SUMMARY - In
the next decades, the world will have to face both an important
increase of the world population and the consequent need
for a dramatic growth of the food production including milk.
Due to the environmental constraints, the technological
advances in intensification will probably not to be sufficient,
control, management and valorisation of the residues of
the activities will be a challenge to achieve a true sustainable
development. Milk production is a very complex activity
with big amounts and diversity of residues. In France, a
method called DEXEL has been extended in both dairy and
meat cows, poultry and pig farms for the diagnosis of effluents
(green and white waters) and residues (manure) and their
management (Nitrogen balance). This nationwide method has
been used by a large program supported financially by the
public services for investment in the improvement of production
systems and equipment in dairy production.
The communication describes the method, the organization
and starts the discussion on the possible application of
its main principles in other socio-economical conditions.
The special situation and alternative solutions for pastoral
grazing systems are underlined in terms of utilization and
management of animal based wastes.
Key –Words : Residues, management, fertilization, milk production,
sustainability
Introduction
Being one of the more developed agricultural
and livestock producer, the amount of agricultural residues
and wastes in France, is
very important. Its estimation is about 55 million tons
from agricultural residues, 45 million tons of residues
from the forestry exploitation and above all, 250 millions tons of organic wastes, mainly
due to livestock production (Thermya, 2007). By comparison,
the total amount of domestic wastes in France is now
22 million tons for a total expense of 11 billions
€. But these residues and wastes of the agricultural
and livestock activities in France could be used and valorised
to prevent pollution and produce energy. In animal production
sector, most of the residues are composed by the dejections
of the animals (solid and liquid manure, brown waters) and
the residues of the products themselves (white waters for
milk production, silage juices). During decades, these dejections
and residues have not really been considered in the management
of the production systems. Their fertilizing values have
been largely underestimated in favour of mineral fertilizers
and the old traditional methods have been very often forgotten
in the more intensive systems and particularly in the western
countries. Nevertheless, under the pressure of local environmental
associations and because of the always higher effects of
the industrial animal sectors (poultry, pigs, and more recently
dairy cows) in often very populated regions, new environmental
regulations have imposed strict standards to control the
effect of these units on environment.
The awareness of the environmental impact of the
animal activities has not been limited at the level of the
more industrialized countries and the intensive animal production
systems have been developed in all continents.
In an always more
global world, the recent evidence of the global warming
and general deterioration of environmental world conditions
has focused on all human activities including obviously
agriculture and animal production. A recent FAO report has
underlined that animal production would be one of the main
responsible for emission of CO2 and that the world production
of meat and milk are likely to double in the next 20 years
with its related effects on residues.
Such a dramatic
situation imposes significant and collective actions to
limit these environmental effects. If more research results
are necessary before operative actions to control the emission
of CO2, the preservation of water quality and a more rationalised
management of fertilisation is largely possible thanks to
a strict stocking and management of the residues.
The aim of this
communication is to present the situation and the action
has engaged in France on these subjects for 14 years to
support the animal farms for a better management of their
residues and to discuss the condition of application in
other situations. The specific case of extensive systems
will be included in this discussion.
1
- The DEXEL method to improve the environmental situation
of the French animal farms
1.1 -The French
situation on pollutions of animal origin
In France, like
in many other European countries, we have observed an important
development of the animal production sector since the end
of the second world war and their concentration in some
regions. Although the bovine, caprine and ovine livestock
have regularly decreased, the porcine one has increased
from 10 millions heads to 15 millions heads, the poultry
one has doubled
from 1360 millions heads to 2800 millions. The drained and
irrigated lands have been multiplied by 4 in 30 years. 52%
of the methane emission in France comes from livestock production
(CITEPA, 2000). One consequence of such a situation has
been a structural excess in nitrates water contents overtaking
the European standard of 50 mg/l and in bacteriological
quality (see table 1). Meanwhile the consumption of mineral
fertilizers had regularly increased of 4 N2 units/year/ha
until the end of the 20th Century. An average
increase of the nitrate content of 1 to 2 mg/litre in surface
and deep waters has been observed during the past 30 years.
The Nitrogen excretion
by animal production can be estimated thanks to the French
Official Corpen standards.
Table 1 - N2
effluent productions /type of animal (kg N2/animal/year)
( industrial pigs, poultry and beef excepted)
|
Type of animal |
kg N2/animal/year |
Livestock
(* 000 heads -2005) |
Total N2
(t-estimation) |
| Dairy cows : |
85 |
3895 |
331 075 |
|
Suckling cows : |
67 |
4029 |
269 334 |
| Sows for reproduction : |
17,5 |
1284 |
22 470 |
|
Total N2 by livestock for reproduction |
|
|
629 000 |
The table above
shows that the Nitrogen produced by dairy and suckling cows,
and sows for reproduction would be equivalent nearly
2 millions tonnes of mineral fertilizers. Only the non controllable
part of it would be used directly for grass production when
animals are grazing. The controllable fraction has to be
stocked and spread in the fields. For many years, these
liquid and solid manures were not included in the fertilisation
management. Because of the low cost of energy, they were
losses both for environment and energy preservation. The
Dexel method like all the rationalised fertilisation plans
aim to include them with both economical and environmental
effects without impact on crop yields. For instance 1 tonne
of solid bovine manure contains an average 5 N2
Units. 20 t /ha could save 100 U mineral fertilization.
If we include the poultry, porcine, and bovine industrial
units, the impact of these residues would be significantly
higher
Fig 1 – Map of
the vulnerable zones for water quality in France
In each region
and departments, the animal farms have to be in compliance
with the Departmental Sanitary Regulations that compel to
suppress any direct dumping of animal residues and dejections.
To apply the European Nitrates Regulation (1991) on water
quality, the French public services in coordination with
professional organisations have defined a plan to control
the pollutions of agricultural origin including animal production
(PMPOA).During the first period (1994-2000) the
biggest farms only were concerned by the plan but since
2000 all the milk, meat, poultry and pig units of the vulnerable
zones have been involved.
1.2 - Objectives,
organisation and main principles of the DEXEL method
Created by the
French Technical Institute for Animal Production (“Institut
de l’Elevage”), the DEXEL diagnosis has received the agreement
of the Ministries of Agriculture and Sustainable Development,
and the Water Authorities to be realised by certified experts
in animal units where PMPOA has to be applied for the management
of residues and the plan of modernisation of the animal
housing.
The DEXEL diagnosis
aims to identify and classify according to a hierarchy the
pollution dangers of waters by nitrates and indirectly by
pathogenic bacteria. It is realised in 3 stages (see figure
2).
The first one
“building and stocking units” identifies the animal housing
and the several building units, the effluent stocking units,
and their management according to the number of heads, the
type of animal and the effluents produced by each of them.
The second one
“Agronomy” does the stocktaking of each land plot, describes
the production system according to the crops and forage,
output and practices in mineral fertilization.
The third one
is dedicated to the dangers analysis, the agronomic indicators
being sum up, the spread organic and mineral fertilizers
being located and the stocking
equipment described.
The main dangers for pollution are identified and characterised
but they are connected
in a global integrated approach of the management
of the effluents and fertilization. The DEXEL method is
based upon the declarations of the farmers and is derived
from the main principles of the Hazard Analysis Critical
Control Points (HACCP).
Fig 2 Main principles of the DEXEL Method
A synthesis is
discussed with the farmer to propose progresses in the management
of fertilization and to improve the equipment and buildings
of the farms.
To make this work
operational, the authors of the methods have prepared
references to guide and ease the calculation. One
difficulty, for instance, is to estimate, the amount of
N2 exported on the grazing areas. A method has been proposed
to simplify the estimation according to the potential of
the meadows, the animal stocking rate, the type of animals
and the time of presence of animals. A common dossier
has been prepared with
clear forms and explanations on the calculation methods. Some examples are given in annex. The objective is to reach the
level of the “farm of pure water”.
1.3 - Application
of the method in France
This method has been applied in France since 1994 and more than 1300
experts have been trained to make the diagnosis. The method
has been improved during all this long period and for instance
a software has been created to facilitate the work of the
DEXEL agents and other individual or collective method have
been created to support the breeders in environmental management
of their farm (ADELE, PAQVEL). The impact of these training sessions has been very important
to make the technicians in animal production aware of the
situation and stakes of many animal farms. Like in many
other countries, investment on residues management and rationalised
equipment was not really considered important because not
directly productive. In the last period, the method has
been improved to be easier to apply and quicker to realise.
Although this
methods and its development have not solved all the negative
externalities of animal production, it has significantly
contributed to reduce them. Simultaneously, other actions
have been engaged for instance to collect the silage films
or the plastic empties.
This continuous
success has been the result of a good coordination and agreements
between the public services (that have supported financially
the method) and professional organisations that are particularly
well structured in France. Beyond, it is important to underline
that in many cases, the recommendations have been applied,
firstly because, significant financial supports have been
dedicated to residues management and under condition of
application of the method, secondly because France has created
a dense network of extension agents in all the regions.
2- Discussion
: teachings and limits of this methods for other countries
From this significant
experience, we can underline that
to impulse the management of residues in animal production
requires several conditions :
-
a high financial background to solve the
identified problems that could be from private or public
origin.
-
a collective organisation and will to train
the farmers who were not always conscious initially of the
importance of this management. The farmers are generally
afraid that the valorisation of manure would reduce their
drops and requires much “bureaucracy”.
-
Efficient public services to make apply
the regulation.
The method, we
have described here is very well adapted for the very intensive
units that have developed dramatically in the Western countries
and in the suburban very populated areas. It could be applied
in many countries with similar conditions. It is also a
good example of the importance of a political decision to
impulse structural changes. An adapted sensitisation on
these problems and these method with lighter procedures
in many developing countries where suburban areas are facing
dramatic problems partly because of the settlement of huge poultry, pig or even
beef intensive units.
This method has
insisted on the global and technical management of the animal
wastes in well organised units. For small family livestock
units, particularly in mountainous areas, there could be
too little available for spreading these effluents and the
effluent management could be a problem. Aubry et al. (2006) have developed a synthetic representation
of practical knowledge about farmers practices. Their model
was based on data collected through expertise, bibliography,
and farm surveys, in La Reunion, a tropical and mountainous
southern French island. They have shown that the effluent management
is more reasoned in terms of spreading dates than in terms
of quantities, always very difficult to estimate. A more
empirical and more traditional close to the farmers practices
would be necessary for small and medium family units but
in all cases, didactic and collective financial efforts
would be required when investment is necessary. The development
of methods of treatment of the residues like composting
or production of bio gas (in addition with valorisation
of other vegetal residues could be planned. The process
is now operating (see annex3) and numerous projects have
began to build such units to produce electricity in many
countries (like for instance the French Indian cooperation
project to build a biomass power plant in India to produce
50 000 MW with agricultural and organic residues, 2005).
Nevertheless, the development of biogas plants using animal
dejections keeps low in France (Observatory of energy 2002)
as shown on table below and information, training and financial
aid are needed to impulse these innovations. .
Table 2- Renewable energy
from agricultural, industrial and domestic residues by biogas productionin France
1999 - 2000 and2001 provisional (source DGEMP, May 2002)
*
production of renewable thermal energy
(heat or driving force)
For the extensive
pastoral systems, the question of land available and concentration
of wastes is less accurate but efforts have to be focused
on the protection of the water collecting areas from the
dung pats of the flocks and herds and the storage and control
of chemical products for veterinary or sanitary purpose.
Conclusion
For the near future,
the mission of extension services will be not only to support
the farmers to produce more but also to help them to take
in account the environmental situation in spite of their
economical difficulties.
In all the continents, the preservation of bacteriological
and chemical quality of water will be a strategic challenge
for mankind. We will have to calculate more and to be more
trained. The management of effluents and residues has to
be organised everywhere including small farms. The traditional know how could be a way to limit the utilization
of expensive chemical products with an high environmental
impact. These subjects would not be limited to water quality
preservation. Although in no word, the DEXEL method can
not be considered a model for other situations and countries,
it has been an innovative and demonstrative approach of
the need for more adapted and teaching support. Nevertheless,
the food urgencies could prioritise short terms solutions
rather than sustainable rationalised but more expensive
ones. It is the reason why it seems to be so important to
create didactic and collective methods to undertake dramatic
changes everywhere in our management of our resources.
References
Actu Environnement, 2005. http://www.actu-environnement.com/ae/news/1253.php4
Aubry,
Ch., Paillat, J-M, Guerrin, F.; 2006. A conceptual representation
of animal waste management at the farm scale: The case of
the Reunion Island .; Agricultural Systems; 88; 2-3. ; 294-315
CITEPA, 2000.
http://www.citepa.org/emissions/nationale/Ges/ges_ch4.htm
FAO ; 2007 ; Livestock’s long shadow ; environmental
issues and options ; http://www.virtualcentre.org
Manneville
Vincent, 2004, Synthèse sur le diagnostic des exploitations
d’élevage, Institut de l’élevage ; 85pp. Can
be consulted in French at :
http://www.inst-elevage.asso.fr/html1/IMG/pdf/Dexel_Methode_et_referentiel.pdf
French Ministry
of Agriculture; Official statistics (1970 –2000)
Thermya SA; 2007.
http://www.thermya.com/pdf/la_biomasse.pdf
Agence
thermique Energie Environnement (2007); http://www.biogaz.atee.fr
Appendix 1– examples of information and calculation forms for the Dexel diagnosis
Appendix 2
– Scheme of a Biogas production unit
