Digestive efficiency of the growing rabbit
according to the restriction strategy
and the dietary energy concentration
T. Gidenne, Fortun-Lamothe L., Combes S.
INRA Toulouse, GenPhySE unit, France
65th Annual meeting of the European Federation of Animal Science
25-29 August 2014 ; Copenhagen, Denmark
CONTEXT
AND AIM
Intake limitation strategies after weaning of the rabbit
• Improve the digestive health (-20% intake respect to ad libitum)
• Improve the digestive efficiency and feed conversion
large variability among studies
Hypothesis
• Effect of the intake amount only ?
• Combined effect with digestible energy intake ? Or
diet composition.
• Interaction ?
Aim:
separate the effects of the ingested amount of those
from energy intake
.02
Experimental design
Model 2 X 2 : 100 vs 80% et Control vs High Energy "H"
Trial1 : 4 groups of 12 rabbits in metabolism cages
+ trial 2: 4 groups of 17 cages of 5 rabbits
(intake and growth measurements)
weaning
63d.
35d. old
70d.
Control diet + free intake (Ad Libitum)
Control diet + limited intake (80% of AL)
H diet + free intake
H diet + limited intake
(80% of AL)
(C100)
Ad Libitum
(C80)
Ad libitum
(H100)
Ad libitum
(H80)
49 to 53d
Fecal collections
Individual & total
.03
Ingredients and chemical composition of the experimental diets
Control
High energy
Ingredients (g/kg)
Wheat
Barley
Wheat bran
Soya bean meal
Sunflower meal
Alfalfa
Wheat straw
Sugarbeet pulp
Vegetable oil
Minerals + vitam.
115
115
190
40
160
190
68
100
0
22
60
60
190
115
140
190
63
100
60
22
148
141
19
337
169
164
91
72
345
157
Starch vs lipids
+ iso-ADF
Chemical composition (g/kg)
Crude protein (N X 6.25)
Starch
Crude fat
Neutral detergent fibre
Acid detergent fibre
.04
Results & discussion
Control vs High energy
Starch vs lipids / iso-ADF
Feed intake (trial 2)
From 35 to 49d
180
160
feed intake regulated
according to dietary DE
concentration
-5.4%
+46%
140
+43%
120
Back to free intake:
sharp increase of intake for
previously restricted rabbits
100
80
60
35-49d
C100
49-63d
H100
63-70d
C80
H80
.05
Nutrient digestion
Diet
Whole tract digestibility, %
90
Intake
DxI
Energy : <0.001
<0.001
0.012
C.P. : <0.001
<0.001
0.22
+7.1pts
+5.2pts
80
+5.3pts
+2.7pts
70
Energy digestion
improved by restriction,
but more with HE diet
60
50
Energy
C100
Crude protein
H100
C80
H80
Protein digestion highly
improved by restriction,
without interaction with
diet composition
.06
Diets
Energy intake
Control vs High energy
MJ ED/kg
Intake of digestible energy*
Ad-lib.
MJ/d
9.71 +12.2% 10.90
Restricted 10.14 +16.4% 11.80
NS
1,4
MJ ED/kg
+4.5%
+9%
1,2
+8.3%
1
0,8
Higher digestive efficiency
for the restricted rabbit
with a high energy diet
0,6
0,4
0,2
0
35-63d
C100
H100
C80
H80
Interaction
energy concentration
and energy digestion?
* : trial 2, measured on 17 cages of 5 rabbits per group
.07
Growth
Control vs High energy
(trial2)
Weight gain, g/d
75
70
35-49d
Intake level = **
65
+51%
60
[ Energy] =
55
49-63d
Intake level = **
[ Energy] = NS
50
45
40
63-70d
[Energy] = NS
35
30
**
35-49d
C100
49-63d
H100
63-70d
C80
Weight at slaughter (73d), g
2724
2787
2650
H80
***
Intake level :
High
compensatory growth
2693
.08
Feed conversion (trial2)
Control vs High energy
NS
3,50
3,00
35-49d
intake level; no effect
2,50
[Energy] = **
2,00
63-70d
[Energy] = NS
1,50
1,00
35-49d
C100
49-63d
H100
63-70d
C80
Intake level : ***
compensatory
growth
H80
.09
Health status (trial2)
Control vs High energy
Number of cases, for 85 rabbits per group (17 cages)
51
46
41
36
31
26
21
16
11
6
1
Mortality:
Lower for "80" restricted
groups (P=0.02)
35 -->70 d of age
Mortality:
[Energy] : unfavourable
effect (P=0.11) ??
Deads
C100
Morbids
H100
Deads+Morb
C80
49-63d : high incidence of cases
H80
Morbidity:
Higher number of cases,
only for high energy +
restriction = interaction?
Health risk (dead+morb)
[Energy] : unfavourable
effect (P=0.05)
.010
CONCLUSIONS
Limited intake level (-20% from AL) for 4 weeks =
1. Better digestion and feed efficiency
2. lower growth almost compensated at end of fattening
with one week of free intake
3. lower mortality
High dietary energy concentration :
• Interaction "energy level" X restriction for energy digestion
• Reduce the "negative impact" of a limited intake on growth
• Impact on digestive health ?? Interaction
.011
Thank you for your attention
Our team SYSED / NED
Sylvie Combes
Laurence
Fortun-Lamothe
Valérie Lozano
Laurent Cauquil
Olivier Zemb
Béatrice
Gabinaud
Christine
Julien
Carole Bannelier
Muriel Segura
Christelle Knudsen
Francis Enjalbert
Corine
Bayourthe
Géraldine
Pascal
Viviane Batailler
Annabelle
Troegeler
Marie Luce
Chemit