Impact of Selection for Digestive Efficiency on Microbiota Composition in the Chicken.
OBJECTIVE
Feed efficiency and its digestive component, digestive efficiency, are key factors in the environmental impact and economic output of poultry production. The interaction between the host and intestinal microbiota has a crucial role in the determination of the ability of the bird to digest its food and to the birds' feed efficiency. We therefore investigated the phenotypic and genetic relationships between birds' efficiency and the composition of the cecal microbiota in a F2 cross between broiler lines divergently selected for their high or low digestive efficiency.


METHODS
Analyses were performed on 144 birds with extreme feed efficiency values at 3 weeks, with feed conversion values of 1.41±0.05 and 2.02±0.04 in the efficient and non-efficient groups, respectively. The total numbers of Lactobacillus, L. salivarius, L. crispatus, C. coccoides, C. leptum and E. coli per gram of cecal content were measured.


RESULTS
The two groups mainly differed in larger counts of Lactobacillus, L. salivarius and E. coli in less efficient birds. The equilibrium between bacterial groups was also affected, efficient birds showing higher C. leptum, C. coccoides and L. salivarius to E. coli ratios. The heritability of the composition of microbiota was also estimated and L. crispatus, C. leptum, and C. coccoides to E. coli ratios were moderately but significantly heritable (0.16 to 0.24). The coefficient of fecal digestive use of dry matter was genetically and positively correlated with L. crispatus, C. leptum, C. coccoides (0.50 to 0.76) and negatively with E. coli (-0.66). Lipid digestibility was negatively correlated with E. coli (-0.64), and AMEn positively correlated with C. coccoides and with the C. coccoides to Lactobacillus ratio (0.48 to 0.64). We also detected 14 Quantitative Trait Loci (QTL) for microbiota on the host genome, mostly on C. leptum and Lactobacillus. The QTL for C. leptum on GGA6 was close to genome-wide significance. This region mainly includes genes involved in anti-inflammatory responses and in the motility of the gastrointestinal tract.
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Sandrine
S
Mignon-Grasteau
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Agnès
A
Narcy
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Nicole
N
Rideau
INRA, LABOGENA, Domaine de Vilvert, Jouy en Josas cedex, France.
Céline
C
Chantry-Darmon
INRA, LABOGENA, Domaine de Vilvert, Jouy en Josas cedex, France.
Marie-Yvonne
MY
Boscher
INRA, UE1295 PEAT, Nouzilly, France.
Nadine
N
Sellier
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Marie
M
Chabault
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Barbara
B
Konsak-Ilievski
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Elisabeth
E
Le Bihan-Duval
UR83 Recherches Avicoles, INRA, Nouzilly, France.
Irène
I
Gabriel
D000818:Animals; D002645:Chickens; D004063:Digestion / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology; D007778:Lactobacillus / Q000235:genetics / Q000502:physiology; D064307:Microbiota / Q000235:genetics / Q000502:physiology*; D040641:Quantitative Trait Loci / Q000235:genetics