Agriculture Reference
In-Depth Information
each simulation, and only one factor will dif-
fer among them.
21 to day 28; 3225 kcal ME/kg, 20% CP from
day 29 to day 41) as shown Table 9.1 .
Reference scenario
Effect of indoor temperature
The reference scenario (Ref.) simulates the
performances of fast-growing broilers (Ross
PM3) reared at an animal density of 15 birds/
m² between 21 and 41 days of age. During
this period, birds were given two successive
diets (3175 kcal ME/kg, 21% CP from day
To show the influence of the temperature on
broiler performances through the regulation
of feed intake (see 'Feed intake regulation:
the notion of a thermostat'), we investigated a
scenario (T+6) in which we simulated the ef-
fect of chronic exposure to higher temperatures
The parameters for the calibration are
the index of maintenance ( IM ,
maintenance requirements) and the
activity factor ( AF , animal behaviour)
Model calibration
Global feed conversion ratio
Cumulated weight gain (g)
2
2000
Reference
Calibration
Reference
1.5
1000
Calibration
1
0
21
24
27
30 33
Age (days)
36
39
42
21
24
27
30 33
Age (days)
36
39
42
Calibration
Reference (your data)
Calibration
Reference (your data)
Adjust these parameters to
fit calibration (blue) with
reference (red)
IM
AF
68
0.3
Fig. 9.6. Calibration curves of the INAVI simulation model. IM (maintenance requirements coefficient) and
AF (activity factor, slope of change in physical activity with age) should be moved up to a strict recovery of
the calibration and reference curves of global feed conversion ratio and cumulative weight gain.
Table 9.1. Scenarios tested by INAVI simulation model.
Fine particle level
in feed (<0.5 mm)
Scenario
Feed ME content
Feed CP content
Indoor temperature
Reference (Ref.)
21- 28 days:
3175 kcal/kg
29- 41 days:
3225 kcal/kg
21- 24 days: 24°C
25- 28 days: 23°C
29- 32 days: 22°C
33- 41 days: 21°C
21- 28 days: 21%
29- 41 days: 20%
0%
T+6
Ref.
Ref.
+6°C compared to Ref.
Ref.
Fine100%
Ref.
Ref.
Ref.
21- 34 days: Ref.
35- 41 days: 100%
ME: metabolizable energy; CP: crude protein; Ref.: reference scenario; T+6: constant heat stress of 6°C; Fine100%: 100%
fine particles (<0.5 mm) instead of pellets for 7 days.
 
 
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