1. Excretion factors
Task 2: In-depth analysis of methodologies for calculation and presentation
Léon Šebek, 28 March 2014

2. Aim of Task 2 For 10 selected EU-27 countries
Identify and analyse differences in methodologies
Point out accuracy and reliability of the excretion coefficients in use
Compare excretion coefficients

3. Countries under consideration
Denmark, Estonia,
France, Germany,
Ireland, Italy, The
Netherlands, Poland,
Spain and
the United Kingdom

4. Different methodologies Methods for quantifying excretion coefficients for livestock
Direct measurements of manure in storage
Direct excretion measurements with livestock
Metabolic and mechanistic models
Input-output measurements (balance method)

5. Accuracy and reliability
Balance method building blocks for N and P excretion coefficients (kg per animal per year)
Level 1
Level 2
Level 3
Output
Input
Data origin
Accuracy and reliability

6. Accuracy and reliability of excretion coefficients
Method used
Measurements, models, defaults or expert judgement?
Aggregation level: animal or country?
Building block level?
Data origin
Statistical reference
Update interval
Comparing quality

7. Accuracy and reliability Quality of data origin
Statistical
reference
Update interval in years
Over-all 1
2-5
5-10
>10
score
Yes No
1 Measurements input-output
Animal x
1Y1
Farm
1Y2
Region
1Y3
Country
1Y4
2 Modelling approach
2Y1
2Y2 X
2N1
2N2
3 Measurements manure
animal category
3N1
animal species
3N2
3N3
3N4
4 Defaults
4Y2
4Y3
common literature
4N2
country specific information
4N3
5 Expert judgement
5Y3
5Y4
5N3

8. Accuracy and reliability building blocks of balance method
Data origin

9. Accuracy and reliability Quality of data origin
Building block
Country DK Fr
Ger
Irl It NL UK
Esp P
Est
N intake
1Y1
2Y1
2Y2
2Y3
5N4
5N1
N deposition
5N3
Feed intake
1Y3
4N3
5Y1
Feed composition
Animal production
3Y1
Animal composition
4Y1
4Y2
Method used B
SFOM1
IPCC
1) SFOM: A tool for simulating quantity and quality of organic fertilizers produced at the farm. Jadczyszyn, e.a., 2000.
Building block
Country DK Fr
Ger
Irl It NL UK
Esp P
Est
N intake
+++ ++ +
--- -
N deposition --
Feed intake
+/-
Feed composition
Animal production
Animal composition
Total
Method used B
SFOM
IPCC

10. Conclusions methods, accuracy and reliability Estimating N and P excretion coefficients at national level
Best method available: balance method
Accuracy and reliability is strongly affected by quality of data origin
Data preferably from well documented origin, regular updates and with respect to all building blocks of the balance method
For the 8 out of 10 selected countries: sufficient accuracy and reliability to make direct comparisons

11. Comparing excretion coefficients Animal categorization
National total N and P excretions
animal numbers x average excretion per animal (kg/year)
Different species and different animal categories
Large differences in categorization between countries
Categorization based on husbandry systems
Data collection based on local categorization
Uniform categorization
Farm System Survey or Livestock registers
Possible loss of quality of data origin

12. N excretion coefficients cattle for some selected countries (kg/animal/year)
Category
France2
Germany2
Netherlands2
Poland1
Dairy
Milk (kg/yr)
weight (kg)
136.7
>5000
105.6
86.7
6000
114.5
7000
125.2
119.3
8000
133.0
9000
144.9
>10.000
160.4
Beef
0-440
29.0
30-640
37.3
32.3
22.8
45-625
35.3
45-700
40.1
1) Not balance method, but system based on mineral excretion by manure.
2) Different excretion coefficients related to well defined different diets

13. N excretion coefficients pigs for some selected countries (kg/animal/year)
Category
Denmark
France3
Germany4
Ireland
Spain
Average present sow incl. piglets to weaning
26.41
20.4 – 24.6
20.1
20.44
Average present sow incl. piglets up to the grower period
34.9–37.3
26.22
Weaned piglets
0.532
0.56–0.622
3.3 – 3.4
6.5
1.71
Growing–finishing pig
3.12
3.8–4.62
10.96
7.69
1) Based on a performance level of 26.0 weaned piglets (7.3 kg) per sow per year.
2) Animal basis
3) First value is based on a 2-phase feeding system; the second value is based on a standard feeding system.
4) Based on a performance level of 22.0 weaned piglets (28 kg) per sow per year. The first value is based on N/P low diets, the second value is based on standard diets.
5) Based on growth rate of 800 g/d.
6) Range of 25 – 100 kg BW.

14. N excretion coefficients poultry for some selected countries (kg/animal/year)
Category
Denmark
France
Germany1
Italy UK
Broiler chickens, 30 days
0.317
Broiler chickens, 32 days
0.346
Broiler chickens, 35 days
0.395
Broiler chickens, 40 days
0.478
0.36
0.429
Broiler chickens, 45 days
0.563
0.0512
Barn-reared chickens, 56 days1
0.351
0.0682
Broiler chickens organic, 81 days1
0.508
0.1252
Laying hens, free-range
0.875
0.703
0.830
Laying hens, organic
1.010
0.718
Laying hens, barn-reared
0.864
Laying hens, cages
0.684
0.713
0.754
0.720
1) The first value is based on N/P low diets, the second value is based on standard diets.
2) On an animal basis.
3) Variation due to different strains.

15. Conclusions comparison of countries Estimating N and P excretion coefficients at national level
Observed differences between countries largely due to regional differences
Animal husbandry systems
Animal categorization
Uniform animal categorization
Clarity in what is compared
Possible negative effect on data quality
when uniform categorization differs significantly from local categorization

16. National N and P excretion proposal for a common method for EU-27
Uniform animal categories
Country specific defaults per uniform animal category
Based on calculations with balance method for regional animal categories
Translate regional category defaults to uniform category defaults
Check national excretion
Update of defaults in short intervals (1-3 years)

17. Thank you for your attention!
Discussion