Elevage Biologique - Itab

Individual variability in exploratory behaviour in organic broiler production
Germain K. 1 , Simonet P. 1 , Leterrier C. 2 , Juin H. 1 , Guémené D. 3,4
1
INRA, UE 1206- Elevage alternatif et santé des monogastriques, Le Magneraud, F-17700 Saint Pierre d’Amilly
2
INRA, UMR 85, Physiologie de la reproduction et des comportements, F-37380 Nouzilly
3
INRA, UR 83 –Unité de recherches avicoles, F-37380 Nouzilly
4
SYSAAF, Centre INRA de Tours , UR 83, F-37380 Nouzilly
Introduction
In France, organic broilers production is increasing. From a behavioural point of view, very few data are available about the use of space
under such rearing conditions. Studies in free-range previously showed that the outdoor runs offered to the birds are often poorly used and
that some laying out encourage chickens to move away from the house (Mirabito et al., 2002). The aim of the present study was to
characterise exploratory behaviour of chickens in two free range systems, one of a meadow type and one planted with trees and to
focus on inter-individual variability in this behaviour.
Material and Methods
Animals and rearing systems (Germain et al., 2010a)
- Experimental facility on INRA Le Magneraud (Platform “AlterAvi”).
- 8 units with a 75 m² mobile barn and a 2 500 m² outdoor run each
- Outdoor runs : oak plantation (n=4) or meadow type (n=4).
- 6000 broilers (750/unit) reared until 84 days of age (Avril 2009-Juillet 2009)
- Outdoor run access after 28 days of age.
Observational technique
- 100 birds/unit equipped with a numbered poncho (Figure 1).
- Behavioural observations conducted on Day 35, 49 and 63.
- 7 scans / day.
- 16 predefined areas : Zone A, B, C and D, divided in 4 observation areas each. (Figure 2).
- Measures : number of tagged birds went outside each observation day, number of bird was
seen outside over the 7 scans, and number of areas used by each bird.
100
90
80
70
60
50
40
30
20
10
0
* *
Day 35 Day 49 Day 63
Figure 3. Percentage of tagged chickens seen outside the house
(* indicates significant differences between « Trees » and « Meadow »)
Trees
Meadow
Results
3
2,5
2
1,5
1
,5
0
Zone A
Zone B
Zone C
Zone D
5 m
10 m
15 m
20 m
* * *
Building
12,5 m
1 2 3 4
Day 35 Day 49 Day 63
Figure 4. Occurrence of observations outside the house per chicken per day
(* indicates significant differences between « Trees » and « Meadow »)
Figure 1 : Tagged bird
Observer
Figure 2 : Predefined
areas of a outdoor run
Trees
Meadow
70
60
50
40
30
20
10
0
M B A
M B A M B A
Day 35 Day 49 Day 63
Figure 5. Percentage of chickens seen outside in the morning only (M) (6 - 11H),
in the afternoon only (A) (after 14H) or in both parts of the day (B).
3
Day 49
3
Day 63
2,5
2,5
2
2
1,5
1,5
1
a b b c c 1
a b bc c c
,5
,5
0
0
0 1 2 3 4 or more
0 1 2 3 4 or more
Figure 6. Influence of the number of areas in Zone A used on D35 (X axis)
on the average number of areas used on D49 and D63.
(The number of areas used per day can vary from 0 to 7. Different letters indicate significant differences)
Conclusion
⇒ The percentage of tagged birds seen outside increased with age and was higher in units with trees on Day 49 and 63 (Figure 3).
⇒ Birds were seen outside the house only 1.9 time over the daily scans as an average, but this number increased with age and was higher
in units with trees (Figure 4). This increase in exploratory behaviour can be explained by anti-predator behaviour. Indeed, in the present
study, the mortality due to predation was higher in M units (Germain et al., 2010b).
⇒ There was a broiler inter-individual variability in the use of space but the daily rhythm was less apparent with age (Figure 5).
⇒ The activity of the birds at an early age (Day 35) was correlated with the one observed on Day 49 and 63 (Figure 6).
⇒ Nevertheless, when considering the entire rearing period, some birds could be considered as sedentary, remaining inside over most
scans, while others were considered as exploratory.
References
GERMAIN K., JUIN H., GUÉMENÉ D. 2010a. AlterAvi: an experimental facility to investigate free range and organic poultry production. Proceedings of the 13th European Poultry Conference. Tours 23-25 August 2010.
GERMAIN K., JUIN H., LESSIRE M. 2010b. Effect of the outdoor run characteristics on growth performance in broiler organic production. Proceedings of the 13th European Poultry Conference. Tours 23-25 August 2010.
MIRABITO L., JOLY T., LUBAC S., AUBERT C., MATHIEU V., HILAIRE C., FAURE J.M., ARNOULD C., CHAUVE C. 2002. Impact of the presence of peach tree orchards and familiar objects in the outdoor runs on the
occupation of the space by "label rouge" type chickens. Sciences & Techniques Avicoles: 29-35
XIII th European Poultry Conference -23-27 August 2010-Tours, France