1. Agroforestry for free-range pig production in Denmark
Authors: Anne Grete Kongsted*, Heidi Mai-Lis Andersen, John E. Hermansen, Dept. Agroecology, Aarhus University, DK
Date AU
University
European Union’s Seventh Framework Program for research, technological development and demonstration under grant agreement no

2. Free-range pig production in DK
Sows
Outdoor all year round on pasture
Nose-ringed
Pregnant sows in groups
Lactating sows in individual paddocks
Piglets weaned at 7-8 weeks of age
Growing pigs
Housed in stables with outdoor runs
2.3 m2/pig
Access to roughage
Slaughtered at 110 kg live weight

3. Why combine pigs and trees?
Overall idea
Increased productivity
Pork and tree biomass produced on the same area
Reduced nitrate leaching because the trees:
have deep root systems with nutrient uptakes across a long growing season
remove N from the area when harvested
are more robust to the pig's rooting behavior than grass

4. Why combine pigs and trees?
Overall idea ….continued
Reduced NH3 volatilization, since trees
Lower the wind speed over the ground
Reduce the solar radiation on the ground
Leaves ‘catch’ nitrogen
Improved animal welfare as the trees provide
Shadow
Shelter
An enriched environment

5. Systems with free-range pigs integrated with energy crops
Objective 1: to identify important challenges in terms of implementing integrated free-range pig and energy crop production in practice
Objective 2: to identify and communicate ‘best practice’ in relation to design and manage an agroforestry system for free-range pig production
Objective 3: to evaluate nutrient emissions, crop damages, crop yields and animal behaviour in a combined energy crop and pig production system

6. Description of the system
An overview over the individual farrowing paddocks with poplar trees

7. Description of the system
Each paddock is separated by an electric fence keeping the sow within the paddock,
but allows the piglets to run between paddocks

8. Description of the system
The paddock are provided with a hut, a feed- and water trough.
During warm periods a mud wallow is established to avoid sun burn

9. Description of the system
The low electric fence makes it possible to drive between paddocks with for example feed,
drinking water or water for the wallow

10. Description of the system
The trees as e.g. poplar and willows can be harvested on a regularly basis to produce tree biomass that can be used as e.g. rooting material for the growing pigs

11. Description of the system
The sows use the trees to provide shadows and rubbing for skin care

12. Description of the system
The sows use of the tress (rubbing and biting) can causes bark damages on individual trees, however the trees recover well during a year without pigs

13. Description of the system
The trees should be protected against the sows until the trees are four years (poplar). The piglets can have access after two years. This reduces the need for supplementing weed control

14. Preliminary results Benefits and challenges from the farmers point of view
The positive benefits of the systems were considered by the farmers to be
improved animal health and welfare
landscape aesthetics
reduced nutrient leaching and ammonia losses
enhanced biodiversity.

15. Preliminary results Benefits and challenges from the farmers point of view
The key negative issues of the systems were considered to be:
the administrative burden in relation to CAP support payment and labour requirements
The key challenges and constraints included
the fencing of the paddocks
restrictions in machinery access
the uncertainty over the profitability of the system

16. Preliminary results Effect of trees on environment
Nutrient surpluses in paddocks with lactating sows are often very high mainly due to high nutrient inputs from concentrated feed
Calculations of N balances at paddock level reveal that removal of N from tree biomass (20 % tree cover in each paddock) are not enough to counteract the high surpluses even if the trees (including leaves) are harvested once every year.

17. Preliminary results Effect of trees on environment
To reduce the risk of nutrient leaching in integrated systems with trees it is important that the majority of feces and urine is deposited close to the trees, however:
When the trees are placed at the end of the lactating paddock, a large proportion of the excretory behavior is performed outside the tree area.
The excretory behavior was affected by the hut and feed location
We expect that the majority of the urine and feces would be deposited in the tree area if the trees were places in the middle of the paddock with the main resources (hut and feed) placed on each side of the tree area

18. Recommendations
Poplar trees should be established at least four years before sow access to prevent destruction. Piglets can have access after two years without destroying the trees.
Cutting all branches in 1 m height seems to reduce tree bark damages of poplar trees. Further, it reduces the risk of sows using the branches as nest material in the farrowing huts. The latter may increase the risk of piglet mortality because the piglets’ mobility inside the hut is inhibited the first hours after birth.

19. Recommendations
Two rows of 4-year old poplar trees in each paddock established with 3 m intra- and inter-row spacing are not enough to prevent sunburn of lactating sows under Danish conditions. A mud wallow should therefore be provided.

20. Read and see more…
More details at: crops.html
A video clip from one of the farms:
pEcosystem (A Danish project, in Danish):
Homepage of one of the farms (in Danish):

21. European Union’s Seventh Framework Program for research, technological development and demonstration under grant agreement no