the interaction and mc4r genotype on feed and · 2015. 9. 15. · the interaction of gender and...
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The interaction of gender and MC4R genotype on feed intake and lean meat gain in growing finishing pigs
A. Van den Broeke, M. Aluwé, F. TuyttensS. Janssens, A. Coussé, N. Buys, S. Millet
Institute for Agricultural and Fisheries ResearchAnimal Sciences Unit
www.ilvo.vlaanderen.be
EAAP 2014
IntroductionMelanocortin 4 receptor: (Asp298Asn polymorphism)
→ association studies→ increased daily gain and lower lean meat content in pigs
Rodents and human: feed intake Effect on feed intake in pigs not well studiedAim: • effect on DFI• effect on DG and DLMG• effects on carcass quality • effect on FCR
Function MC4R
Function MC4R in rodents and humans:• part of leptin‐melanocortin pathway
• information adipose ssue → hypothalamic responses
• changes in feed intake andmetabolic rate
Leptin-melanocortin pathway
Leptin
ARC
Anorexigenic signalDecreased feed intakePVN
AgRP
AgRP
MC4R
MC4RMC4R
MC4R
MC4R
AgRP α-MSH
α-MSH
Other sites
AgRP
AgRP
AgRP
MC4R
MC4R
MC4R
MC4R MC4R
α-MSH
α-MSHMC4R
α-MSH
Increased energy expenditure
‐
LEPR
LEPR
LEPR
LEPR
α-MSHMC4R
Experimental design• interventional study• offspring of a commercial cross (hybrid sow X Piétrain) • Homozygous littermates of AG sow x AG sire
n EM G
AA 6ˣ11 6ˣ11
GG 6ˣ11 6ˣ11
Performances
• ad libitum three phase‐ feeding• 20‐40 kg: NEv: 9.6 MJ/kg; dLYS: 9.5 g/kg• 40‐70 kg: NEv: 9.4 MJ/kg; dLYS: 8.5 g/kg• 70‐110 kg: NEv 9.2 MJ/kg; dLYS: 7.5 g/kg
• Weekly data collection• individual weight• feed consumption per pen
• Slaughter: intended average live weight of 110 kg
Carcass quality
Carcass quality (n= 237)Individual data collection in slaughterhouse
• muscle thickness• backfat thickness• meat percentage
Performances: DFI
Gender P=0.528
Genotype P=0.001
1700
1800
1900
2000
2100
2200
g
Average daily feed intake (mean ± s.d.)
EM AA EM GG G AA G GG
n=44 pens
Performances: ADG
Gender P<0.001
Genotype P<0.001
GenderˣGenotype P=0.044
700725750775800825850875900925
g
Average daily gain
EM AA EM GG G AA G GG
bb
n=254 animals
a
b
Performances: DLMG
Gender P=0.051
Genotype P=0.544
n=254 animals
340
360
380
400
420
440
460
g
Daily lean meat gain
EM AA EM GG G AA G GG
Carcass quality
• No gender x genotype interaction for any carcass trait
0
5
10
15
20
mm
Back fat thickness
EM AA EM GG G AA G GG
Carcass quality: fat
CGM device
Gender P=0.875
Genotype P<0.001
60
61
62
63
64
65
66
67
%
Meat percentage
EM AA EM GG G AA G GG
Carcass quality
Gender P=0.281
Genotype P<0.001
2.2
2.3
2.4
2.5
2.6
2.7
2.8
g/g
Feed conversion ratio
EM AA EM GG G AA G GG
Gender P<0.001
Genotype P=0.570
Performances: FCRn=44 pens
• ↑ DG of AA animals due to↑ DFI• No effect on DLMG • Extra DG: extra fat deposition
• No effect on FCR although AA lower lean meat percentage: • faster growth AA animals: relatively lower maintenance requirements
• decreased energy expenditure??
Discussion
Leptin-melanocortin pathway
Leptin
LEPR
LEPR
ARC LEPR
LEPR
Anorexigenic signalDecreased feed intake
α-MSH
PVN
AgRP
AgRP
MC4R
MC4RMC4R
MC4R
MC4R
MC4R
AgRP α-MSH
α-MSH
Other sites
AgRP
AgRP
AgRP
MC4R
MC4R
MC4R
MC4R MC4R
α-MSH
α-MSHMC4R
α-MSH
Increased energy expenditure
‐
Leptin-melanocortin pathway
Leptin
ARC
Anorexigenic signalDecreased feed intake
α-MSH
PVN
AgRP
AgRP
MC4R
MC4RMC4R
MC4R
MC4R
MC4R
AgRP α-MSH
α-MSH
Other sites
AgRP
AgRP
AgRP
MC4R
MC4R
MC4R
MC4R MC4R
α-MSH
α-MSHMC4R
α-MSH
Increased energy expenditure
‐
??
??LEPR
LEPR
LEPR
LEPR
AA GG
Conclusions
↑ ADFI ↓
↑ ADG, EM ↓
↓ Meat percentage ↑
↑ Back fat thickness
↓
Thank you for your attention!