Animal 19 (2025) 101673
Con en s lis s a ailable a ScienceDi ec
Animal
The in e na ional jou nal o animal biosci ences
Pa e ns o plasma sexual s e oids in Du oc and Pie ain c ossb ed male
pigs in o ganic a ming and p edic ion o boa ain isk acco ding o
slaugh e weigh
A. P unie ,
PEGASE, INRAE, Ins i u Ag o, 35590 Sain -Gilles, F ance
B. Leb e
⁎
a i c l e i n o
A icle his o y:
Recei ed 28 Ap il 2025
Re ised 23 Sep embe 2025
Accep ed 23 Sep embe 2025
A ailable online 29 Sep embe 2025
Keywo ds:
17b–oes adiol
And os enone
Boa
Ska ole
Tes os e one
a b s a c
Boa ain isk in po k highly depends on a issue concen a ions o and os enone and ska ole, and
indole o a lowe ex en . Du ing pube al de elopmen , and os enone is inc easingly p oduced by es es
and accumula es in a issues. Ska ole and indole a e p oduced and abso bed along in he colon and also
accumula e in a issues. Ska ole and indole a e ca abolised in he li e , bu sexual s e oids (including
and os enone) inhibi hei li e deg ada ion. The e o e, slaugh e ing pigs be o e he pube al peak o
s e oid p oduc ion should educe boa ain isk and hus make i possible o aise male pigs wi hou
in lic ing de imen al cas a ion. In he p esen expe imen , non-cas a ed male pigs om wo geno ypes
di e ing in hei p opensi y o accumula e and os enone and ska ole in back a we e compa ed: La ge
Whi e × Du oc (D; n = 47) and La ge Whi e × Pie ain c ossb eds (P; n = 34). Blood samples we e d awn
om he jugula ein wo imes du ing g ow h (a a ound 85 kg BW and 133 days o age, and a ound
105 kg BW and 153 days o age) and he day be o e slaugh e (a ound 125 kg BW and 174 days o
age). Plasma es os e one and 17b-oes adiol, whose concen a ions inc ease du ing sexual de elopmen ,
we e measu ed in all samples and co ela ed wi h back a concen a ions o and os enone, ska ole and
indole measu ed a slaugh e . Plasma concen a ions o bo h ho mones inc eased (P < 0.05) om he i s
o he second, and om he second o he hi d sampling s age (P < 0.05). Plasma es os e one concen-
a ion did no di e be ween geno ypes (P > 0.1) whe eas plasma 17b-oes adiol was mo e han wice
highe in D han in P pigs (P < 0.001) ega dless o he age. Plasma 17b-oes adiol concen a ion measu ed
he day be o e slaugh e was highly co ela ed wi h back a and os enone ( = 0.91, P < 0.001). Es ima ing
back a and os enone concen a ion om ha o plasma 17b-oes adiol allowed o p edic ha educing
slaugh e BW om mo e han 125 kg o less han 110 kg would educe he pe cen age o ca casses wi h
and os enone concen a ion abo e 1.7
l
g/g liquid a (se e e h eshold limi o boa ain ) om 42 o
29% in D pigs and om 10 o 0% in P pigs, and wi h and os enone concen a ion abo e 3
l
g/g (less se e e
limi o boa ain ) om 19 o 7% in D pigs, whe eas none o he P pigs would be abo e his limi ega d-
less o he age. In conclusion, pig geno ype and educing slaugh e BW (and age) a e s ong le e s o a oid
boa ain .
© 2025 The Au ho s. Published by Else ie B.V. on behal o The animal Conso ium. This is an open access
a icle unde he CC BY license (h p://c ea i ecommons.o g/licenses/by/4.0/).
Implica ions
A oiding su gical cas a ion imp o es he wel a e o male pigs
bu he e is a isk o boa ain . This unpleasan odou and la ou
a e mainly due o and os enone and ska ole ha accumula e in a
along pube al de elopmen . The plasma concen a ion o 17b-
oes adiol is a good p edic o o back a and os enone. Thanks o
blood samples a di e en ages/BWs, we showed ha educing
age/BW a slaugh e should be e ec i e in educing he boa ain
isk ela ed o and os enone in Du oc c ossb ed male pigs. In pa -
allel, ska ole should be con olled by husband y p ac ices. Bo h
molecule s a e less p esen in back a o Pie ain c ossb eds.
⁎
Co esponding au ho .
E-mail add esses: [email p o ec ed] (A. P unie ), benedic e.leb e @in ae.
(B. Leb e ).
h ps://doi.o g/10.1016/j.animal.2025.101673
1751-7311/© 2025 The Au ho s. Published by Else ie B.V. on behal o The animal Conso ium.
This is an open access a icle unde he CC BY licens e (h p://c ea i ecommons.o g/licenses/by/4.0/).
In oduc ion
Su gical cas a ion o male pigle s wi hou pain ea men is
highly de imen al o animal wel a e (P unie e al., 2020). Tech-
niques o anaes hesia and analgesia a ailable o male pigle cas-
a ion only pa ially elie e pain (P unie e al., 2020), and
animals lose hei physical in eg i y, ha can be conside ed non-
e hical. The e o e, a be e solu ion, om he animal wel a e poin
o iew, would be a oiding cas a ion and aising non-cas a ed
male pigs, e en i wel a e p oblems ela ed o dele e ious beha-
iou s (moun ing and agg essi e beha iou s) may be encoun e ed
( on Bo ell e al., 2020). A oiding cas a ion o male pigs also has
he ad an age o imp o ing he e iciency o lean mea deposi ion
(be e eed con e sion, g ea e p o ein e en ion) , which educes
he en i onmen al impac s o po k p oduc ion and inc eases he
lean mea con en o ca casses and he e o e hei comme cial
alue (de Roes e al., 2009; Ba o ek e al., 2012a). Howe e , he
mea o non-cas a ed male pigs can p esen an unpleasan odou
and la ou , known as boa ain (Lunds öm e al., 2009). I is
mainly due o and os enone and ska ole ha a e s o ed in adipose
issue since hey a e lipophilic molecules. And os enone is a es ic-
ula s e oid. I s syn hesis and accumula ion in adipose issue
inc ease du ing pube al de elopmen . This pe iod is ma ked by
an inc ease in he syn hesis and elease in he gene al ci cula ion
o nume ous es icula s e oids such as and os enone, 17b-
oes adiol, oes one, es os e one and DHEA, and o hei sulpha ed
o ms (Schwa zenbe ge e al., 1993; Sinclai e al., 2001b;
Zama a skaia e al., 2004). This inc ease s a s be ween 3 and
5 mon hs o age and plasma concen a ions o es icula s e oids
peak a ound 7–8 mon hs o age. Pigs aised o mea p oduc ion
a e usually slaugh e ed a ound 5–6 mon hs o age so ha and os-
enone may ha e ime o accumula e in a (Zama a skaia and
Squi es, 2009). The e o e, and os enone a con en depends on
he s age o pube al de elopmen eached a he slaugh e s age
and hence on pigs’ age/BW a slaugh e as well as on en i onmen-
al ac o s ha may in luence pube al de elopmen (Pa ois e al.,
2018). I is also la gely unde gene ic in luence wi h la ge di e -
ences among some b eeds and a high he i abili y wi hin b eeds
(Zama a skaia and Squi es, 2009; Pa ois e al., 2018). Fo example,
a and os enone has been shown o be highe in Du oc han in
Land ace boa s (Oskam e al., 2010). Finally, wha e e he biologi-
cal eason, high di e ences in a and os enone concen a ion exis
be ween pigs a a gi en age o BW (Zama a skaia and Squi es,
2009). Ska ole is me abolised om yp ophan by gu bac e ia
and i s con en in adipose issue is highly depende n on heal h s a-
us, pig en i onmen al o husband y ac o s, especially s ess
be o e slaugh e (Wesoly e al., 2015), die composi ion (Wesoly
and Weile , 2012; Aluwé e al., 2017; Seoni e al., 2021), pen di -
iness and lack o en ila io n (Hansen e al., 1994; Thomsen e al.,
2015; Pa ois e al., 2017b). In addi ion, es icula s e oids play an
impo an ole in he con ol o ska ole accumula ion since hey
educe he li e ca abolism o ska ole, a ou ing i s ans e in
he gene al ci cula ion and inally i s accumula ion in he adipose
issue (Zama a skaia and Squi es, 2009).
A. P unie and B. Leb e Animal 19 (2025) 101673
In o de o educe he isk o ain ed mea , di e en le e s can
be ac i a ed a a m le el: (a) using a pig geno ype wi h slow sex-
ual de elopmen allowing o slaugh e he male pigs be o e accu-
mula ion o and os enone, (b) using a geno ype wi h a low
po en ial o and os enone accumula ion e en when sexually
ma u e, (c) slaugh e animals a a su icien ly ea ly age/BW o p e-
cede and os enone accumula ion. The s a egy applied in pig a m-
ing and aiming a educing boa ain can be ocused on
and os enone since i s concen a ion may in luence ha o ska ole
due o hei in e ela ed me abolism men ioned abo e and since
le e s ela ed o pig eeding and, pen cleanliness and en ila ion
can be easily ac i a ed by a me s o educe he isk o boa ain
due o ska ole.
In he p esen expe imen , we explo ed he le e o educing
age/BW a slaugh e in wo di e en geno ypes o non-cas a ed
male pigs, La ge Whi e × Pie ain and La ge Whi e × Du oc c osses,
which may ha e di e en back a and os enone concen a ions
(Oskam e al., 2010; Ma hu e al., 2013). Ou wo k is based on
he animal expe imen desc ibed in de ail by Leb e e al. (2024),
aiming a e alua ing he e ec o male pigs’ geno ype: La ge
Whi e × Du oc (D) s La ge Whi e × Pie ain (P) on wel a e indica-
o s, ca cass and po k quali y ai s in o ganic a ming. We demon-
s a ed ha wel a e indica o s (skin sc a ches, ail lesions) showed
less p oblems in D han P c ossb eds, e en hough he occu ence
o hese p oblems was o e all low. G ow h a e and inal BW (a -
e age o 127 kg) did no di e be ween geno ypes, bu D pigs had
lowe ca cass lean mea con en (Table S1) and highe back a con-
cen a ions o and os enone, and o ska ole o a lesse ex en , han
P pigs, sugges ing a highe isk o ejec ion by consume s due o
boa ain . In he p esen s udy, on he same D and P animals, we
measu ed plasma concen a ions o es os e one and 17b−oes a-
diol, wo key es icula s e oids, a h ee di e en physiological
s ages: ea ly and mid- a ening pe iods and he day be o e slaugh-
e , in o de o p edic back a and os enone o male pigs a di e -
en s ages o g ow h in bo h geno ypes. Based on he ac ha
plasma es os e one and e en mo e plasma 17b-oes adiol concen-
a ions a e highly linked o back a and os enone concen a ion
(Pa ois e al., 2015), we hypo hesised ha plasma concen a ion
o hese molecules could p edic back a and os enone and, conse-
quen ly, boa ain isk.
2
Ma e ial and me hods
Animals and expe imen al design
The pigs we e aised a he INRAE Po ganic (ce i ied o ganic)
expe imen al a m (INRAE GenESI, 86 480 Rouillé, F ance;
h ps://doi.o g/10.15454/1. 5572415481185847E12). The expe i-
men al p o ocol was app o ed by he local e hical commi ee
and ob ained he go e nmen al au ho isa ion (see E hics app o al
sec ion below). The expe imen was ca ied ou on a o al o 81
non-cas a ed male pigs bo n om La ge Whi e sows (INRAE Po -
ganic he d) insemina ed wi h semen om ei he Du oc (D;
Nucléus, 35 650 Le Rheu, F ance) o Pie ain NN boa s (P; Nucléus,
non-ca ie s o he halo hane mu a ion a he RYR1 gene and cho-
sen o hei low isk o boa ain ).
The expe imen al p o ocol and housing en i onmen we e
de ailed in (Leb e e al., 2024). B ie ly, pigs we e p oduced in
wo successi e ba ches (6 weeks apa be ween he wo ba ches),
including 30 D and 22 P pigs o he i s ba ch, and 17 D and 12
P pigs o he second ba ch. Expe imen al pigs we e selec ed on
he basis o hei BW a 70 days (a e age and SD o BW we e bal-
anced be ween geno ypes) and aised by geno ype in a collec i e
pen on deep s aw bedding (1.3 m
2
/pig) wi h esh s aw added
weekly, and wi h ee access o a co e ed ou doo a ea on a con-
c e e loo (1.0 m
2
/pig). All animals we e ed ad libi um he same
o ganic g owing (16.01% CP, 9.44 MJ NE/kg, om 10 un il 16 weeks
o age) and inishing die s (14.07% CP, 9.33 MJ NE/kg, om
16 weeks o age un il slaugh e ), as de ailed in Leb e e al.
(2024). The die s we e o mula ed in o de o ul il animal nu i-
ional equi emen s and we e o e ed as pelle s. Pigs had pe ma-
nen access o g assland hay dis ibu ed in a ack in each pen
and had ee access o wa e .
Blood sampling and de e mina ion o plasma s e oid concen a io ns
Pigs we e weighed indi idually a 2-week in e als. Th ee blood
samples we e scheduled pe pig a a ound 85 (S1), 105 (S2) and
125 kg (S3) BW, wi h a minimum o wo weeks be ween wo suc-
cessi e blood samples, he las blood sample being aken he day
be o e slaugh e . In p ac ice, he mean BW was 83 kg (n = 77 pigs),
103 kg (n = 78 pigs) and 127 BW (n = 80 pigs) o he 1s , 2nd and
3 d blood samples, espec i ely, and did no di e be ween geno-
ypes (Table 1). Blood samples we e d awn om he jugula ein.
The s ess associa ed wi h blood sampling was limi ed by using
−−−−−−
−−−−−−
−−−−−−
highly expe ienced echnicians and by imposing a maximum du a-
ion o 2 min o he whole p ocedu e, including ca ching he ani-
mal and applying he lasso o immobilisa ion. Blood was collec ed
in ubes con aining hepa in (10 ml) and cen i uged (2 500 × g o
10 min a +4 °C), and he plasma was s o ed a −20 °C un il anal-
ysis. The h ee blood samples we e collec ed in all excep h ee D
pigs ( wo pigs wi h he i s sample missing, one pig wi h he i s
and second samples missing). Plasma 17b-oes adiol and es os-
e one concen a ions we e measu ed using ELISA ki s (ST AIA-
Pack hsE2 and ST AIA-Pack Tes os e one; Tosoh Co po a ion,
Tokyo, Japan) de eloped o an au oma ic analyse (AIA 1800;
Tosoh Co po a ion) as desc ibed by Pa ois e al. (2017a). As
desc ibed by he manu ac u e o he 17b−oes adiol assay,
c oss− eac i i y wi h he sulpha e o m was low (0.03%). The
de ec ion limi s we e espec i ely 3 pg/ml o plasma o 17b-
oes adiol and 0.01 ng/ml o es os e one. Fo 17b-oes adiol,
in e -assay CVs we e 4.5% and 3.4%, and in a-assay CVs we e 3.2
and 1.4% a 67 and 764 pg/ml, espec i ely. Fo es os e one,
in e -assay CVs we e 6.0 and 2.5% a 0.09 and 1.45 ng/ml, espec-
i ely, and in a-assay CVs we e 5.3and 1.8% a 0.05 and 1.50 ng/
ml, espec i ely.
A. P unie and B. Leb e Animal 19 (2025) 101673
Table 1
In luence o geno ype and s age a blood sampling on age, BW, plasma es os e one and 17 b-oes adiol concen a ions and back a concen a ions o and os enone, ska ole and
indole in non-cas a ed male pigs.
Fi s s age o
blood
sampling
Second s age
o blood
sampling
Thi d s age o
blood
sampling
Du oc
c ossb ed
Pie ain
c ossb eds
P- alue
1
77 pigs 78 pigs 80 pigs 43 o 46 pigs 34 pigs
I em lsmean SE lsmean SE lsmean SE lsmean SE lsmean SE S age Geno ype Ba ch
Age a sampling, days 133
a
1.1 153
b
1.1 174
c
1.1 154 1.4 153 1.7 <0.001 0.59 0.93
BW a sampling, kg 83
a
1.2 103
b
1.2 127
c
1.2 104 1.5 107 1.7 <0.001 0.73 0.24
Plasma es os e one, ng/ml 1.3
a
0.12 2.0
b
0.19 2.9
c
0.27 2.1 0.19 1.7 0.18 <0.001 0.14 <0.001
Plasma 17b−oes adiol, pg/ml 14.0
a
1.64 20.1
b
1.96 26.4
c
2.24 28.8 2.79 12.6 8.68 <0.001 <0.001 0.002
1.32 (0.29,
3.16)
0.60
(0.17,1.40)
Back a and os enone,
l
g/g liquid a
2,3
−0.002 0.004
0.02
(0.02,0.14)
0.02
(0.02,0.03)
Back a ska ole,
l
g/g liquid a
2,3
−0.05 0.75
0.02 (0.02,
0.06)
0.02 (0.02,
0.02)
Back a indole,
l
g/g liquid a
2,3
−0.03 0.08
Abb e ia ion: lsmean = leas -squa e mean.
a, b, c
lsmeans ollowed by di e en supe sc ip s di e ed signi ican ly (P < 0.01).
1
Fo age, BW, es os e one and 17b−oes adiol, P- alues o he ixed e ec s o s age a blood sampling, geno ype and ba ch, ob ained om analyses o a iance applied o
da a ( he in e ac ion Geno ype × S age was emo ed in all models since i was ne e signi ican wi h P > 0.1). Fo and os enone, ska ole and indole, he ba ch and geno ype
e ec s we e analysed by a non-pa ame ic es as indica ed in Leb e e al. (2024).
2
Back a was sampled on ca casses o pigs slaugh e ed he day a e he 3 d blood sampling.
3
Median, and i s and las decile alues be ween b acke s (da a om Leb e e al., 2024).
Slaugh e
In o de o limi a iabili y in BW a slaugh e , pigs we e
slaugh e ed in wo di e en se ies o each ba ch, sepa a ed by
wo (ba ch 1) o h ee weeks (ba ch 2). Slaugh e was pe o med
in a comme cial aba oi (Coope l, 79 800 Sain e-Eanne) a a mean
BW o 125 kg ( ange 96–163 kg) and a mean age o 176 days ( ange
165–191 days). The hea ies hal o he pigs om each geno ype
we e slaugh e ed in he i s se ies, and he o he hal emained
in hei o iginal pen un il he second se ies o slaugh e . The day
be o e slaugh e , pigs we e sampled o blood, indi idually
weighed, and g ouped wi hin geno ype in wo di e en pens om
a oo ed pla o m. No eed was a ailable bu pigs had ee access o
wa e . Du ing he ollowing nigh , all pigs we e loaded in o he
same uck and anspo ed wi hou non-expe imen al pigs o
he slaugh e house (maximum du a ion o 30 min). In he slaugh-
e house, hey we e all placed in a single pen wi h ee wa e a ail-
able (s ill wi hou mixing wi h non-expe imen al pigs) o 50 min
o 2 h. Pigs we e slaugh e ed in he ea ly mo ning using elec ical
s unning a high ol age, ollowed by exsanguina ion.
3
Back a sampling and biochemical analyses o boa ain componen s
Twen y- ou hou s a e slaugh e , a piece o back a (whole
hickness, i.e. including bo h a laye s) was collec ed a he neck
le el, acuum packaged and s o ed a −20 °C un il analysis o
and os enone, ska ole and indole concen a ions by HPLC, as p e i-
ously desc ibed (Ba o ek e al., 2012b; Van Baelen e al., 2024).
Back a sample was missing o one Du oc pig, and his pig was
emo ed om he s a is ical analyses. B ie ly, back a samples
we e mel ed in a mic owa e and cen i uged and he liquid phase
was emo ed and s o ed a −20° C o 2 weeks. All samples we e
analysed by HPLC (Agilen Technologies, 1200 se ies, San a Cla a,
CA, USA) wi h a C18 column (wa e s sun i e, 3.5
l
m, 4.6 × 75 mm,
USA). Flow a e was 1.2 ml/min o ska ole and 1.0 ml/min o
and os enone. The de ec ion limi s we e 0.08
l
g/g o liquid a
o and os enone and 0.02
l
g/g o liquid a o ska ole and indole,
and hese alues we e assigned o pigs wi h concen a ions below
hose limi s.
S a is ical a
nalyses
S a is ical analyses we e pe o med wi h he R so wa e ( e -
sion 4.3.3, The R Co e Team, 2024). Age, BW, plasma es os e one
and plasma 17b-oes adiol we e analysed using an analysis o
a iance (ANOVA) including he geno ype (n = 2), he ba ch
(n = 2) and he sampling s age (n = 3 pe pig excep o wo pigs
wi h one sample and one pig wi h wo samples), he in e ac ion
be ween sampling s age and geno ype as ixed e ec s and he
animal (n = 80) as a andom e ec (lme p ocedu e om he
nlme package and Ano a p ocedu e o he ca package). When
he in e ac ion was no signi ican , i was emo ed om he
model. The no mali y o he dis ibu ion o he esiduals was
checked o each a iable, and leas squa e means as well as
he SEs o he lsmeans we e calcula ed using he lsmeans p oce-
du e o he emmeans package. A squa e- oo ans o ma ion was
applied o plasma 17b-oes adiol and o plasma es os e one o
each a no mal dis ibu ion o he esiduals. Fo hese ans-
o med da a, leas squa e means and SE we e back calcula ed
speci ying ‘‘ ype = esponse” in he lsmeans p ocedu e. Spea man
co ela ions be ween back a and os enone, ska ole and indole
and plasma 17b-oes adiol and es os e one concen a ions we e
calcula ed using aw da a.
A. P unie and B. Leb e Animal 19 (2025) 101673
The in luence o BW on he isk o boa ain was assessed based
on he p edic ion o back a and os enone concen a ion om
plasma 17b-oes adiol concen a ion. Fi s , we checked ha he
ela ionship be ween a and os enone and plasma 17b-
oes adiol a S3 was no in luenced by he geno ype by including
he geno ype, plasma 17b-oes adiol a S3 and hei in e ac ion
as explana o y ac o s o a and os enone using he lm p ocedu e.
The analysis was pe o med on he whole se o 80 pigs a e
squa e oo ans o ma ion o bo h concen a ions o no malise
he da a. Second, he pa ame e s o he linea eg ession be ween
plasma 17b-oes adiol a S3 and a and os enone we e calcula ed.
Thi d, a and os enone was es ima ed om plasma 17b-
oes adiol. Fou h, indi idual es ima ions o a and os enone con-
cen a ions we e alloca ed o h ee classes o pigs acco ding o
hei BW de e mined a blood sampling: 87 o 110 kg BW (n = 9
P plus 14 D pigs), 110 o 125 kg BW (n = 15 P plus 18 D pigs),
and 125 o 163 kg BW (n = 21 P + 26 D pigs). In each class, a gi en
pig was p esen only once. A o al o 23 pigs we e p esen in wo
di e en classes.
Resul s and discussion
Age, BW, plasma es os e one and 17 b-oes adiol a sampling
As shown in Table 1, age and BW inc eased om he i s o he
second, and om he second o he hi d blood sampling s age
(P < 0.001). Age and BW did no di e acco ding o geno ype o
ba ch (P > 0.1). Plasma 17b-oes adiol and es os e one also
inc eased be ween he i s and he second, and be ween he sec-
ond and he hi d blood sampling s ages ( P < 0.001). This is due
o he pig pube al de elopmen in ag eemen wi h p e ious
s udies (Zama a skaia e al., 2004; P unie e al., 2013).
Fig. 1. In luence o geno ype (La ge Whi e × Du oc: D c ossb eds s La ge Whi e × Pie ain: P c ossb eds) in non-cas a ed male pigs on plasma concen a ions (adjus ed
means ± SE) o 17b-oes adiol and es os e one measu ed a h ee s ages du ing g ow h (S age 1: a ound 133 days o age 83 kg o BW, S age 2: a ound 153 days o age and
103 kg o BW, S age 3: a ound 74 days o age and 127 kg o BW). Da a we e analysed by ANOVA wi h geno ype and s age o sampling as main e ec s and pig as a andom
e ec ( he in e ac ion Geno ype × S age was emo ed in all models since i was ne e signi ican wi h P > 0.1). Da a a e ep esen ed as boxplo s a e squa e oo
ans o ma ion, as he s a is ical analyses we e pe o med a e squa e oo ans o ma ion.
4
Plasma es os e one was o e all highe in he i s (2.9 ± 0.24
ng/ml, adjus ed mean ± SE) han in he second ba ch (1.26 ± 0.14
ng/ml, P < 0.001), and his was also he case o plasma 17b-
oes adiol ( i s ba ch: 25.9 ± 2.46 pg/ml, second ba ch: 14.6 ± 2.
46 pg/ml, P < 0.002). This e ec could be explained by he in luence
o he season and especially o he ligh du a ion. Indeed, pigs om
he i s ba ch we e sampled be ween mid-Decembe and ea ly
Feb ua y unde sho e days han hose om he second ba ch ha
we e sampled be ween la e Janua y and la e Ma ch. E en hough
domes ic pigs a e no pu ely seasonal b eede s, hey can be in lu-
enced by he season, wi h a endency o plasma es os e one o
inc ease in male pigs subjec ed o a educ ion in daily ligh du a-
ion (Weile e al., 1996; Ande sson e al., 1998; P unie e al.,
2013). Al e na i ely, he di e ence be ween ba ches may be
explained by indi idual di e ences (Zama a skaia and Squi es,
2009; Pa ois e al., 2018). Indeed, male pigs om he wo ba ches
we e bo n om di e en sows and di e en boa s (only wo ou o
i e Du oc boa s we e simila be ween he wo ba ches). Di e -
ences in he edi a y p opensi y o deposi a and os enone
be ween si es could he e o e also con ibu e o explain he ba ch
e ec on a and os enone concen a ion.
Geno ype had a s ong in luence on plasma 17b-oes adiol wi h
highe alues in D han P pigs ( P < 0.001), bu no on plasma es os-
e one concen a ion (P > 0.10) (Table 1). The in e ac ion be ween
sampling s age and geno ype was no signi ican o he wo ho -
mones (P > 0.1). The di e ence in plasma 17b-oes adiol be ween
geno ypes was al eady p esen a he i s sampling s age, i.e.
a ound 133 days o age and 83 kg o BW (Table 1; Fig. 1). Simila
plasma es os e one bu highe plasma 17b-oes adiol concen a-
ions in Du oc c ossb ed han Pie ain c ossb ed male pigs we e
also obse ed a an ea lie s age, i.e. abou 50 kg BW and 100 days
o age by Hey man e al. (2019). A abou 80 kg BW and 120 days o
age, close o ou i s sampling s age, hese au ho s obse ed again
highe plasma 17b-oes adiol in Du oc han Pie ain c ossb ed
male pigs bu he di e ence was no mo e signi ican . In pa allel
o plasma 17b-oes adiol, back a and os enone concen a ion in
ou s udy was highe in he Du oc han Pie ain c ossb ed pigs
(Table 1). This di e ence be ween he wo geno ypes which is in
ag eemen wi h he li e a u e (We ne e al., 2020) was al eady
discussed in Leb e e al. (2024).
A. P unie and B. Leb e Animal 19 (2025) 101673
Ac oss geno ypes, a and os enone concen a ion was e y
highly co ela ed wi h plasma 17b-oes adiol concen a ion and
signi ican ly co ela ed wi h plasma es os e one concen a ion
(Table 2, Fig. 2). Fa ska ole was signi ican ly co ela ed only wi h
plasma 17b-oes adiol concen a ion bu he co ela ion coe icien
was much lowe han o and os enone (Table 2, Fig. 2). Fa indole
was signi ican ly co ela ed wi h bo h plasma s e oid concen a-
ions and a and os enone, bu he alues o co ela ions we e
mode a e (Table 2). Much highe co ela ion be ween a and os e-
none and plasma 17b-oes adiol han wi h plasma es os e one
was al eady obse ed in pu e Pie ain o Pie ain c ossb ed male
pigs (Pa ois e al., 2015; P unie e al., 2016). The high co ela ion
be ween a and os enone and plasma 17b-oes adiol concen a-
ion sugges s ha his ho mone could be a good es ima o o he
and os enone con en in a issue, as p e iously ound (Pa ois
e al., 2015) bu no o a ska ole. Measu ing oes one sulpha e
in plasma ins ead o 17b-oes adiol, p e ious s udies ha e also
shown close ela ionships be ween a and os enone and oes o-
gen han wi h es os e one, and close ela ionships be ween
plasma s e oids and a and os enone han wi h a ska ole
(Squi es and Lunds om, 1997; Babol e al., 1999; Sinclai e al.,
2001a; Chen e al., 2006).
P edic ion o boa ain isk acco ding o pig geno ype and slaugh e
BW
The s a is ical model explaining a and os enone by plasma
17b-oes adiol a S3, geno ype and hei in e ac ion indica ed
non-signi ican e ec s o he geno ype (P = 0.96) and he in e ac-
ion (P = 0.45), con a ily o 17b−oes adiol concen a ion
(P < 0.0001). Compa ison wi h a s a is ical model including only
plasma 17 b−oes adiol as explana o y a iable indica ed ha he
wo models we e no s a is ically di e en (P = 0.19). The e o e,
i can be concluded ha he ela ionship be ween plasma 17b
−oes adiol and a and os enone is simila in bo h geno ypes, as
illus a ed in Fig. 3, and ha he same coe icien s o linea eg es-
sion can be used in bo h geno ypes o p edic a and os enone
om plasma 17b−oes adiol concen a ion. Since he ela ionship
was es ablished in pigs submi ed o a blood sample be ween
164 and 190 days o age and since i was no possible o demon-
s a e ha i can be applied o younge pigs, he es ima ion o
and os enone was limi ed o blood samples collec ed a a mini-
mum o 164 days o age and hence o only 103 measu es (80 a
S3 and 23 a S2). The ea e , he pe cen ages o pigs abo e 1.7
l
g
and os enone/g o liquid a o abo e 3.0
l
g and os enone/g o liq-
Table 2
Spea man’s co ela ion coe icien s and hei P − alues in b acke s be ween concen a ions o plasma ho mones measu ed he day be o e slaugh e , concen a ions o boa ain
compounds in back a collec ed he day a e slaugh e , age and BW he day be o e slaugh e . Da a we e calcula ed on he whole da a se (n = 80 non-cas a ed male pigs).
Plasma es os e one Fa and os enone Fa ska ole Fa indole Age a sampling BW a sampling
Plasma 17b-oes adiol 0.63 (<0.001) 0.91 (<0.001) 0.28 (0.012) 0.41 (<0.001) −0.02 (<0.85) 0.11 ( <0.34)
Plasma es os e one 1.00 0.58 (<0.001) 0.03 (0.765) 0.36 (<0.001) −0.09 (<0.42) −0.08 (<0.48)
Fa and os enone 1.00 0.22 (0.049) 0.40 (<0.001) −0.08 (<0.48) 0.11 (<0.35)
Fa ska ole 1.00 0.35 (<0.002) −0.07 (<0.54) 0.09 (<0.46)
Fa indole 1.00 −0.05 (<0.65) 0.28 ( <0.02)
Age a sampling 1.00 −0.11 (<0.32)
5
Fig. 2. Rela ionship be ween plasma 17b-oes adiol concen a ion (A) o plasma
es os e one (B) and back a and os enone concen a ion as well as be ween plasma
17b-oes adiol concen a ion and back a ska ole concen a ion (C) in La ge
Whi e × Du oc (D c ossb eds) o La ge Whi e × Pie ain (P c ossb eds) non-
cas a ed male pigs. Blood was collec ed a an a e age o 174 days o age and 127 kg
o BW. Back a was collec ed on ca casses om pigs slaugh e ed he day a e blood
collec ion.
(Bonneau and Che illon, 2012). Howe e , i should be men ioned
ha his limi was de ined o po k wi h low a concen a io n o
ska ole and hence may no be applied when his condi ion is no
sa is ied.
A. P unie and B. Leb e Animal 19 (2025) 101673
Fig. 3. Rela ionship be ween plasma 17b−oes adiol concen a ion (squa e- oo ans o med) and back a and os enone concen a ion in La ge Whi e × Du oc (D c ossb eds)
o La ge Whi e × Pie ain (P c ossb eds). Animals we e classi ied acco ding o geno ype (A) o BW (B). Blood was collec ed a an a e age o 174 days o age and 127 kg o BW.
Back a was collec ed on ca casses om pigs slaugh e ed he day a e blood collec ion.
0
10
20
30
40
50
[87-110] ]110-125] ]125-163]
%,sessac ac oega nec eP
Es ima ed and os enone > 1.7 µg/g liquid a
Dc ossb eds
P c ossb eds
0
10
20
30
40
50
[87-110] ]110-125] ]125-163]
%,sess ac ac oega nec eP
Es ima ed and os enone > 3 .0 µg/g liquid a
Fig. 4. Pe cen ages o ca casses wi h es ima ed back a and os enone concen a ion
abo e 1.7
l
g/g liquid a ( op) o 3.0
l
g/g liquid a (bo om) in La ge Whi e × Du oc
(D c ossb eds) o La ge Whi e × Pie ain (P c ossb eds) non-cas a ed male pigs,
acco ding o hei BW (87 o 110 kg: n = 14 D and 9 P, 110 o 125 kg: n = 18 D and 15
P, 125 o 163 kg, n = 26 D and 21 P). These wo concen a ions co espond o wo
h esholds o back a and os enone concen a ion o consume ejec ion o po k
due o boa ain , p oposed in he li e a u e (Lunds öm e al., 2009; Bonneau and
Che illon, 2012). The absence o ba indica es ha he pe cen age is ze o.
uid a we e calcula ed wi hin geno ype o h ee classes o BW
(Fig. 4). These wo limi s o and os enone concen a ion we e
e ained since a unique h eshold le el o and os enone o con-
sume s’ ejec ion o po k due o boa ain is s ill unde deba e
(Bee e al., 2015). The lowe limi (1.7
l
g/g o liquid a ) co e-
sponds o he limi o 1 ppm o en ci ed in he li e a u e
(Lunds öm e al., 2009) a e con e sion o he uni om ppm in
back a o
l
g/g liquid a as desc ibed by (Pauly e al., 2008).
Indeed, ou and os enone concen a ions we e de e mined in liq-
uid a . The uppe limi (3.0
l
g/g o liquid a ) is de i ed om
he s udy o Bonneau and Che illon (2012) on he consume s’ e al-
ua ion o odou and as e o po k o igina ing om ca casses mea-
su ed o back a and os enone and ska ole concen a ions wi h
exac ly he same echniqu e as used in he p esen s udy
6
In Pie ain c ossb ed male pigs, we p edic ed ha he pe cen -
age o pigs abo e bo h h eshold limi s would be e y low un il
125 kg BW and close o 10% abo e 125 kg BW bu only when con-
side ing he mo e se e e (i.e. lowe back a concen a ion) limi
(Fig. 4). Fo he Du oc c ossb ed male pigs, we obse ed an inc ease
in he boa ain isk, om nea ly 10% below 110 kg BW up o
nea ly 20% abo e 125 kg BW wi h he less se e e (i.e., highe back-
a concen a ion) limi , and om nea ly 30% o mo e han 40%
wi h he mo e se e e limi (Fig. 4).
I is wo h p edic ing he concen a ion o and os enone in a
based on he plasma concen a ion o 17b-oes adiol in pigs less
han 164 days old in o de o assess he in luence on boa ain isk
o a ma ked educ ion in slaugh e age/li e weigh . To do his, he
equa ion ob ained in he p esen s udy would need o be alida ed
by measu ing he concen a ion o bo h molecules in pigs aged
be ween 140 and 164 days. Two op ions a e possible: de elop an
analy ical echnique using a e y small amoun o a in o de o
pe o m a painless biopsy o e y small diame e in li e pigs, o
slaugh e he animals a he desi ed ages in o de o collec he
necessa y quan i y o a om he ca cass.
We did no e alua e he isk o boa ain due o ska ole and
indole since he co ela ions wi h plasma 17b-oes adiol o plasma
es os e one we e qui e low (0.03 ≤ ≤0.41, Table 2). In addi ion,
based on he li e a u e, one can assume ha he isk o boa ain
due o ska ole and indole would mos likely be independen o he
slaugh e BW (Aluwé e al., 2011; P unie e al., 2013) and can be
la gely con olled by nu i ional and/o en i onmen al condi ions
(Hansen e al., 1994; Wesoly and Weile , 2012; Thomsen e al.,
2015; Pa ois e al., 2018).
Conclusion
Ou da a clea ly indica e ha he pube al de elopmen o he
male pigs, as indica ed by he concen a ions in plasma sex s e -
oids, g adually con inues om abou 83 kg BW/133 days o age
o 103 kg BW/153 days and o 127 kg BW/174 days. We also
showed ha he e is a ma ked di e ence be ween Du oc and Pie-
ain c ossb eds o plasma 17b-oes adiol concen a ion, wi h
highe alues o he D pigs, wha e e he sampling s age. Indeed,
plasma 17b-oes adiol was al eady high in Du oc c ossb ed pigs a
he i s sampling s age, wi h a alue simila o ha measu ed in
Pie ain c ossb eds a he hi d sampling s age. Con a ily, plasma
es os e one was simila in bo h b eeds. Plasma 17b-oes adiol
appea s as a good es ima o o back a and os enone concen a ion
and he e o e o boa ain isk due o his molecule. Ou esul s
indica e an inc easing isk o boa ain due o and os enone wi h
inc easing slaugh e BW om less han 110 o mo e han 125 kg
BW, especially in Du oc c ossb ed male pigs.
A. P unie and B. Leb e Animal 19 (2025) 101673
Supplemen a y ma e ial
Supplemen a y Ma e ial o his a icle (h ps://doi.o g/10.
1016/j.animal.2025.101673) can be ound a he oo o he online
page, in he Appendix sec ion.
E hics app o al
All p ocedu es con ibu ing o his wo k complied wi h he
F ench legisla ion on animal expe imen a ion and we e app o ed
by he local Commi ee o Conside a ion o E hics in Animal
Expe imen a ion. On hese bases, he p esen animal expe imen a-
ion was au ho ised by he F ench Minis y o Highe Educa ion,
Resea ch and Inno a ion (Au ho isa ion: APAFIS#30357-
202103041121621 4 deli e ed on July 2, 2021).
Da a and model a ailabili y s a emen
Da a se and lis o a iables ha e been deposi ed in he na ional
eposi o y Reche che Da a Gou : h ps://en epo . eche che.da a.-
gou . /da ase .xh ml?pe sis en Id=h ps://doi.o g/10.57745/
SCSMVX. In o ma ion can be made a ailable om he au ho s upon
eques .
Decla a ion o gene a i e AI and AI-assis ed echnologies in he
w i ing p ocess
Du ing he p epa a ion o his wo k he au ho (s) did no use
any AI and AI-assis ed echnologie s.
Au ho ORCIDs
A. P unie : h ps://o cid.o g/0000-0003-3070-6613.
B. Leb e : h ps://o cid.o g/0000-0001-5435-0389.
CRediT au ho ship con ibu ion s a emen
A. P unie : W i ing – e iew & edi ing, W i ing – o iginal d a ,
Visualisa ion, Valida ion, Me hodology, In es iga ion, Fo mal anal-
ysis, Concep ualisa ion. B. Leb e : W i ing – e iew & edi ing,
W i ing – o iginal d a , Visualisa ion, Valida ion, P ojec adminis-
a ion, Me hodology, In es iga ion, Funding acquisi ion, Fo mal
analysis, Concep ualisa ion.
Decla a ion o in e es
None.
Acknowledgemen s
The au ho s g a e ully acknowledge he s a o INRAE expe i-
men al a m (D. G i aul , T. Te asson, S. Mo eau; GenESI, Po ganic,
86480 Rouillé, F ance) and labo a o ies (R. Com e, L. Le No mand;
PEGASE, 35590 Sain -Gilles, F ance) o hei excellen assis ance.
They also hank S. Fe chaud o coo dina ing he wo k in he expe -
imen al a m. The s a o Coope l A c A lan ique slaugh e house,
79800 Sain e-Eanne, F ance, is also hanked o hei excellen
wo k and hei hos ing.
7
Financial suppo s a emen
The p ojec PPILOW has ecei ed unding om he Eu opean
Union’s Ho izon 2020 esea ch and inno a ion p og amme unde
g an ag eemen N° 816172.
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