LiveM_Macsur_Bilbao_2014

1. Norwegian University of Life Sciences 1
Impact of animal health on greenhouse gas emissions
in Norwegian dairying
Şeyda Özkan, Bouda Vosough Ahmadi, Helge Bonesmo, Olav Østerås,
Alistair Stott, Odd Magne Harstad
Livestock Modelling and Research Colloquium, Maritime Museum Bilbao, Spain
16 October 2014

2. Outline
• Introduction
• Mitigation and Animal Health
• High somatic cell count and replacement decisions
• Dynamic Programming & HolosNor
• Results & Discussion
• Final Remarks
Norwegian University of Life Sciences 2

3. Introduction
• GHG emissions in Norway increased by 6% between 1990 and 2011 (53.4 Mt CO2e in total).
• 4.5 MtCO2e emissions produced from agriculture in 2011 (a reduction by 11% from 1990 levels).
• About 90% of agricultural emissions in Norway are attributed to feed and livestock production.
• Emissions associated with production of concentrates and vegetables are rather low.
• Instead, a large proportion of arable land is only suitable for pasture production that can be grazed by
ruminants
• Dairy sector contributes 30% (plus emissions from replacement cows) of GHG emissions from animal
production.
• Major GHGs from agriculture are CH4 and N2O.
• Projected increase in population (and increased demand for food production) by 20% by 2030 is likely to
increase GHG emissions.
• Norwegian Ministry of Agriculture and Food suggests a 20% reduction in agricultural emissions from 1990
levels by 2020.
Norwegian University of Life Sciences 3

4. Norwegian University of Life Sciences 4
Animal type Numbers (1000) CH4
Enteric
CH4
Fertiliser
N2O
Total %
Dairy cattle 204 620 74 188 882 30
Beef cattle 70 174 19 34 227 8
Young cattle 476 627 99 157 883 30
Total 750 1421 192 379 1992 68
Sheep 1513 454 24 124 602 20
Goat 61 17 1 7 25 1
Horse 67 25 24 25 74 2
Pigs 561 23 30 52 105 4
Poultry 14803 2 36 33 71 2
Fur animal 212 0 3 8 11 <1
Other animals 76 14 16 106 4
TOTAL 2018 324 644 2986
Proportions among sources 67 11 22
Source: Grønlund and Harstad (2014
Table: Distribution of emissions between different animal categories

5. Animal Health
• Many studies on the impact of animal- and diet-related
factors on mitigating emissions
• Lack of research on the impact of management related
factors e.g. health, calving interval, fertility, extended
lactation
• Subclinical mastitis – somatic cell count
• Aim: Impact of high somatic cell count (and replacement
decisions) on GHG emissios
Norwegian University of Life Sciences 5

6. DP model - HolosNor
• A DP model of dairy cow replacement decision problem
• optimised total culling rate (voluntary and involuntary)
• Objective of the DP : maximise the expected gross
margins over feed (ENPV) by making appropriate
replacement decisions.
• HolosNor - farm-scale model
• Combined dairy and beef farming systems
• Accounts for all significant GHGs including soil C
changes
Norwegian University of Life Sciences 6

7. 3 scenarios examined
(i) a healthy herd with a somatic cell count of 50 000
cells/ml and below, and milk price of 4.7 NOK/kg;
(ii) a diseased herd with a somatic cell count of 200 000
cells/ml and above, and milk price of 4.7 NOK/kg;
(iii) a diseased herd in (ii) but with a milk price of 3.76
NOK/kg due to penalty.
Norwegian University of Life Sciences 7

8. Results - DP
Norwegian University of Life Sciences 8
Healthy
SCC (milk
@4.7/kg) S1
SCC (milk
@3.76/kg) S2
ENPV (NOK/year) 34 800 34 600 27 700
Voluntary culling rate (%) 10 13 12
Involuntary culling rate (%) 22 25 25
Total culling rate (%) 32 38 37
Table. The output of the DP model for ENPV and culling rates

9. Results - HolosNor
Norwegian University of Life Sciences 9
3.05
6.45
3.12
5.62
3.12
5.73
0
1
2
3
4
5
6
7
milk meat
kg CO2e emissions
kg product
H
S1
S2
Figure. The GHG emissions produced for kg milk and meat under three scenarios examined

10. Discussion
• Higher ENPVs in healthy herds than the diseased herds
(34 800 versus 34 600 and 27 700 NOK/year for healthy
and diseased cows, respectively).
• Increased GHG emissions per kg milk can be, in part,
attributed to the increased culling rate in the diseased
scenario, resulting in a younger herd
• The reduction in the GHG emissions produced per kg of
meat may be due to higher number of older than second
lactating cows in healthy herds than those in diseased
herds
Norwegian University of Life Sciences 10

11. Conclusion
• Potential for mitigation in herds with subclinical mastitis
• Ongoing studies on
-impact of varying SCC
-impact of higher heifer prices
- Varying penalties
- Extended lactation
- Fertility problems
- Diseases
Norwegian University of Life Sciences 11

12. Thank you
Şeyda Özkan
Department of Animal and Aquacultural Sciences
Norwegian University of Life Sciences
seyda.ozkan@nmbu.no