Relationship between sperm production and boar taint risk
of purebred or crossbred entire offspring
Marie-José MERCAT,
[email protected]
Background
Genetics is a lever to reduce boar taint
Androstenone and skatole are heritable traits
Parois, JAS 2015,
93: 8: 3749-3758
Boar taint is related to sexual development
Strong genetic correlations with sexual steroids
Selection against boar taint might impact reproduction
66th EAAP Annual meeting , Warsaw, Poland 2015
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Mercat, Session 3
Objective
Study the link between
Sperm production of Artificial Insemination Center (AIC) boars
and
Boar taint risk of their purebred or crossbred offspring
Thanks to Utopige, a genomic selection program
L. Tusell, C. Larzul
H. Gilbert
EAAP 2015
S. Schwob
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Experimental design
INRA UETP
testing station
100 AIC Pietrain boars
3 varieties : 74 V1 ♂, 10 V2 ♂ and 16 V3 ♂
12 production sites
Sperm production data
7,6 purebred offspring
7,8 crossbred offspring from LW type sows
Entire male slaughtered around 110 kg live weight
Androstenone and skatole quantification
Liquid Chromatography in liquid fats
66th EAAP Annual meeting , Warsaw, Poland 2015
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Mercat, Session 3
Semen data analyzes
Total number of spermatozoa per semen collection
Gamma law, GLIMMIX SAS procedure
90 sperm collections per AIC boar on average
Repeated effect
Sire
Fixed effects
Random effect
Season (n=5)
Age class (n=3)
Number of collects in 15d (n=4)
Production site (n=12)
Covariates
Delay between collects
Age at collection (intra age class)
Mean predicted sperm production for each sire
Relation?
Boar taint risk of offspring
66th EAAP Annual meeting , Warsaw, Poland 2015
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Low boar taint odor risk as a whole
Total : 1 544 animals
ANDROSTENONE
ND
60%
]0.24 - 1]
50%
]1 - 2]
]2 - 3]
40%
>3µg/g
30%
20%
10%
0%
2.8%
1.6%
Purebred
Crossbred
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Low boar taint odor risk as a whole
Total : 1 544 animals
ANDROSTENONE
ND
60%
]0.24 - 1]
50%
]1 - 2]
]2 - 3]
40%
>3 µg/g
30%
20%
10%
0%
2.8%
1.6%
Purebred
Crossbred
66th EAAP Annual meeting , Warsaw, Poland 2015
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Low boar taint odor risk as a whole
Total : 1 544 animals
ANDROSTENONE
SKATOLE
ND
60%
]0,24 - 1]
50%
]1 - 2]
]2 - 3]
40%
>3 µg/g
30%
Less than 4% > 0.2 µg/g
Global risk
Global risk=0 Free of odor
Androstenone < 1 µg/g
and skatole < 0.2 µg/g
20%
10%
0%
2.8%
1.6%
Purebred
Global risk≠0 Potential risk
Androstenone ≥ 1 µg/g
and skatole ≥ 0.2 µg/g
Crossbred
66th EAAP Annual meeting , Warsaw, Poland 2015
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Percentage of odor free offspring (Global Risk=0) as a
function of sperm production
Quartile ranking of the AIC boars / their mean predicted sperm production
V1 variety boars
100%
Relative evolution of the %
offspring free of odor
95%
90%
85%
80%
All offspring
75%
70%
Q1
Q2
Q3
Q4
Sperm production
66th EAAP Annual meeting , Warsaw, Poland 2015
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Percentage of odor free offspring (Global Risk=0) as a
function of sperm production
Quartile ranking of the AIC boars / their mean predicted sperm production
V1 variety boars
Crossbred Q4-Q1
-10% odor free
Significant Khi-2
100%
Relative evolution of the %
offspring free of odor
95%
90%
85%
All offspring
Purebred offspring
Crossbred offspring
80%
75%
70%
Q1
Q2
Q3
Q4
Sperm production
66th EAAP Annual meeting , Warsaw, Poland 2015
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Mercat, Session 3
Percentage of odor free offspring (Global Risk=0) as a
function of sperm production
Quartile ranking of the AIC boars / their mean predicted sperm production
V1 variety boars
Crossbred Q4-Q1
-10% odor free
Significant Khi-2
Three Pietrain varieties
Same trends
Greater differences
Crossbred Q4-Q1 -25% odor free
V2 and V3 Pietrain varieties alone
Non significant Khi-2: lack of power?
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Average sperm production of the sires per
androstenone class
100
Average predicted sperm production of the sires for
each androstenone concentration class
V1 + V2 + V3 boars
Billions spermatozoa / collection
d
95
Andro ND
c
8,5 Billion/collection
b
90
Andro [0.24 - 1]
Andro [1 - 3]
a
85
Andro >3
80
All offspring
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Average sperm production of the sires per
androstenone class
100
Pour Average
chaque classe
predicted
de concentration
sperm production
en androsténone,
of the sires forcalcul
each de la
moyenne des productions
androstenone
spermatiques
concentration
prédites
class
moyennes des pères
d
V1 + V2 + V3 boars
Billions spermatozoa / collection
d
95
c
b
90
b
8,5
b ab
Andro ND
a
Andro [0.24 - 1]
b
4,4
a
10,8
c
Andro [1 - 3]
a
Andro >3
85
80
All offspring
66th EAAP Annual meeting , Warsaw, Poland 2015
Purebred offspring
13
Crossbred offspring
Mercat, Session 3
Conclusions
In an experiment with a low boar taint risk as a whole
A relation between sperm production of the sires and the risk of
odor of the offspring has been shown
Sires with higher sperm productivity have less offspring free of boar taint odor
than sires with lower sperm productivity
Sires of offspring with high androstenone contents produce more
spermatozoa than sires of offspring with low or undetectable contents
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Conclusions
Relation found with the 3 Pietrain varieties and with the V1 alone
But not with V2 et V3 Pietrain varieties alone (smaller sample size)
Effects are more pronounced on crossbred offspring than on purebred
offspring
Selection against odorous compounds might negatively impact
boar sperm production if reproduction traits are not included in
the breeding goal
In some populations like the V1 Pietrain variety
We will go on studying the link between boar taint and sperm
production in the frame of a new research program
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Acknowledgments
To Artificial Insemination
Centers
Choice Genetics France
Cobiporc
Gènes Diffusion
To the funders
ANR : ANR10-GENOM
BTV015
BIOPORC
INAPORC
To the UETP and
Pegase INRA
staff
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FranceAgrimer
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Thank you for your attention
www.ifip.asso.fr