fibre structure and metabolites in m. longissimus dorsi of wild boar, pietrain and meishan pigs as...

Fachgebiet Tierzuchtung und Biotechnologie, Institut fur Tierhaltung und Tierzuchtung, UniversitatHohenheim, Garbenstraße 17, 70599 Stuttgart, Germany

Fibre structure and metabolites in M. longissimus dorsi of WildBoar, Pietrain and Meishan pigs as well as their crossbred

generations

BY E. MULLER, M. RUTTEN, G. MOSER, G. REINER, H. BARTENSCHLAGER andH. GELDERMANN

SummaryFibre traits and glycolytic metabolites in musculus longissimus dorsi of European Wild Boar, Pietrainand Meishan as well as their F1 and F2 crossbred generations were evaluated and compared. Pietrainhad the highest relative number of white fibres and the largest muscle fibres. Wild Boar showed thesmallest muscle fibres. The R-value and lactate level of Wild Boar and Meishan were low, whereasPietrain had high R-values and lactate levels. The glycogen level was highest in Wild Boar and lowestin Meishan. The F1- and F2-crossbreds often had trait values between those of their founder breeds.Several antagonistic relations between fibre characteristics, muscle metabolites and performance traitsfor carcass and meat quality have been found. They are family-specific and strongest within thecrossbreds of the Pietrain-based families.

Zusammenfassung

Faserstruktur und Metabolitenwerte im M. longissimus dorsi bei Wildschwein, Pietrain und Meishanund deren Kreuzungsgenerationen

Merkmale der Muskelfasern sowie glykolytische Parameter im Musculus longissimus dorsi wurden furEuropaisches Wildschwein, Pietrain und Meishan untersucht. Schweine der Rasse Pietrain hatten denhochsten Anteil an weißen Fasern und die großten Muskelfasern. Die Wildschweine zeigten diekleinsten Muskelfasern. R-Wert und Laktatgehalt waren bei Wildschwein und Meishan niedrig,wahrend die Rasse Pietrain hohe R-Werte und Laktatgehalte aufwies. Wildschweine hatten diehochsten, Meishan die niedrigsten Glykogengehalte. Die Merkmalswerte der F1- und F2-Kreuzungenlagen oftmals zwischen denen der jeweiligen Ausgangsherkunfte. Antagonistische Beziehungenzwischen Fasermerkmalen und Muskelmetaboliten und der Schlachtkorperzusammensetzung bzw.Fleischbeschaffenheit waren familienspezifisch und zeigten sich besonders in den Kreuzungsherkunf-ten mit Pietrain-Anteil.

Introduction

Meat mainly contains skeletal muscle composed of fibres with various characteristics. Thenumber of muscle fibres is assumed to be determined at birth and, therefore, growth offibres is defined by an increase in length and cross-sectional area (ESSEN-GUSTAVSSON

1993). The main function of fibres is to convert chemical energy from ATP into mechanicalenergy. Regeneration of ATP uses blood-borne substrates as glucose and free fatty acids,and intramuscular substrates as glycogen and triglycerides. Glycogen is the most importantsubstrate for ATP regeneration by anaerobic processes, associated with production oflactate.

Skeletal muscles consist of different fibre types. Histochemical staining methods are usedto identify different fibre types on the basis of their reaction of enzyme activity. Methodsusing myosin ATPase allow the differentiation of type I, IIA and IIB fibres within the same

J. Anim. Breed. Genet. 119 (2002), 125–137� 2002 Blackwell Verlag, BerlinISSN 0931–2668

Ms. received: 10.03.2000Ms. accepted: 20.11.2001

U.S. Copyright Clearance Center Code Statement: 0931–2668/2002/1902–0125 $15.00/0 www.blackwell.de/synergy

muscle preparation (ESSEN-GUSTAVSSON 1993). Slow-contracting (red) fibres (type I fibres)are oxidative with a low ATPase activity. These fibres contain many mitochondria andmuch lipid and myoglobin, but little glycogen. On the other hand, rapidly contracting(white) fibres are non-oxidative with a high ATPase activity (type IIB fibres). Theseglycolytic fibres have few mitochondria, little myoglobin and lipid contents, but highglycogen levels. Muscles also contain a third fibre type (type IIA fibres), which are bothoxidative and fast-contracting (RUUSUNEN 1994).

Meat quality in pigs is influenced by the profile of muscle fibre types, the fibre diameter(FEWSON et al. 1993) and the rate of post-mortem glycogenolysis (MULLER 1994). Asglycogen breakdown is controlled by a few key enzymes only (SCHWAGELE et al. 1996a,1996b), their activities as well as the metabolites of the glycolytic pathway can be used toestimate the rate of glycogenolysis. It is well known that pigs selected on a high meatcontent, like those of the breed Pietrain, have large fibres as well as a high rate of post-mortem glycogenolysis (FEWSON et al. 1993; MULLER 1994), whereas most unselected pigslike wild boar have small fibres (RAHELIC and PUAC 1981; FIEDLER et al. 1998) and a lowrate of post-mortem glycogenolysis (REDE et al. 1986). Genetic factors, age, nutrition,physical activity and hormones are known to influence fibre composition and metabolicprofiles.

The objective of this report was to analyse muscle fibre profiles as well as the content ofglycolytic metabolites in M. longissimus dorsi of European Wild Boar, Pietrain andMeishan as well as their F1- and F2-crossbred generations. Thereby the genetic influenceson muscle tissue can be compared between the wild ancestor, an unselected domestic breedand a commercial breed selected especially for muscling.

Materials and methods

Animals and sampling

Three groups of F1 animals were generated with pure-bred European Wild Boar · Pietrain(W · P), Meishan · Pietrain (M · P) and Wild Boar · Meishan (W · M) crosses. Eachgroup of F1 animals was used for the production of F2 animals. Experimental design anddevelopment of the resource populations were described by GELDERMANN et al. (1996).The pigs of both sexes were housed at the experimental station ‘Unterer Lindenhof’,University of Hohenheim. A cereal diet was fed ad libitum and the body weights of eachanimal were recorded weekly. The pigs were slaughtered at an age of 210 days(SD ± 6 days). A panel of performance traits for fattening, carcass composition, meatquality and stress reaction was recorded.

Tissue samples from M. longissimus dorsi were taken from the left-hand side of thecarcass, about 5 cm from the midline between the 13th and 14th rib directly afterexsanguination. The muscle samples were cut into pieces of approximately0.5 · 0.5 · 1.0 cm, immediately fixed in liquid nitrogen (N2) and stored for furtherpreparations at – 80�C. Table 1 shows the number of animals used for the various traits.

Table 1. Number of animals per genetic group measured for the different groups of traits

W · P M · P W · M

Group of traits Wild Boar (W) Meishan (M) Pietrain (P) F1 F2 F1 F2 F1 F2

Fibre criteria 10 66 56 77 291 88 309 35 342Metabolites 8 64 58 76 306 93 310 31 321Protein content 8 67 58 76 307 93 310 33 340

126 E. Muller et al.

Measurements of fibres

Cross-sections of muscle (10 lm) were cut at ) 20�C with a cryostat microtome (Leitz,Germany) and stained using the myosin ATPase method after SZENTKUTI and EGGERS

(1985) with an alkaline pre-incubation buffer (pH 10.4). Stained muscle fibre preparationswere examined by an image analysis system and the computer program AMBA (IBSB,Berlin, Germany). The scanning was done directly from the histological preparations witha standard microscope (Zeiss, Germany) and a video camera. Alternatively, negativephotographs of stained muscle fibres were scanned. The scanning system was calibrated byusing a standard slide (Zeiss). Definitions of the fibre types according to SZENTKUTI andEGGERS (1985) were applied as follows:

‘White fibres’: rapidly contracting glycolytic fibres with high ATPase activity‘Red fibres’: slow-contracting oxidative fibres with low ATPase activity‘Intermediate fibres’ fast-contracting oxidative fibres with intermediate ATPase activity.

Traits of muscle fibres were defined:

Average size: average area of fibres classified in each of the specific types (lm2)Average diameter: average diameter of fibres classified in each of the specific types,

measured according to the KRUMBEIN method (BEYERSDORFER et al. 1985; lm)Relative number: number of a specific type of fibre relative to the total number of fibres

(%)Relative area: area of a specific type of fibre relative to the total fibre area (%).

In order to test the repeatability, samples from 15 F2(M · P) animals were included.From each animal, three muscle samples were produced, and for each sample threedifferent areas were scanned. At least 100 fibres per area were measured two times for thedifferent parameters by one person. Repeatabilities of the different fibre traits with 3, 6 or 9scans per animal were calculated. As given in Table 2, repeatabilities from threemeasurements were > 0.90 for most of the traits. All repeatabilities from six and ninemeasurements were > 0.95 (not given).

Table 2. Repeatability for fibre traits including three scans per animal (n = 15) with 100 fibersmeasured per scana

Fibre type Average size (lm2) Average diameter (lm) Relative number (%) Relative area (%)

White fibres 0.94 0.92 0.91 0.80Red fibres 0.89 0.90 0.89 0.78

aIntermediate fibres were not included due to low numbers observed

Table 3. Measurements of metabolites

Trait Unit Method

R-value No dimension HONIKEL and FISCHER (1977)Glycogen lmol/g tissue BERGMEYER (1974)Glucose-6-phosphate (G6P) lmol/g tissue BERGMEYER (1974)Glucose-1-phosphate (G1P)Lactate lmol/g tissue BOEHRINGER, GermanyProtein content mg/g tissue LOWRY et al. (1951)

127Fibre structure and metabolites in M. longissimus dorsi of Wild Boar and pigs

Measurements of metabolites and protein content

The traits and methods used for measuring metabolites are shown in Table 3. About100 mg of muscle tissue were homogenized in 3 ml 0.6 N perchloric acid and, aftercentrifugation and filtration, the glycolytic metabolites were measured in the supernatant.For measurements of protein content, about 200 mg of muscle tissue were homogenized in10 ml 0.15 M KCl solution. After centrifugation and filtration, the protein concentrationwas determined in the supernatant according to LOWRY et al. (1951). The glycolyticpotential (GP; lmol lactate equivalents per g tissue) was calculated as follows: GP ¼lactate + 2 (glycogen + G1P + G6P) according to MONIN and SELLIER (1985), by using theconcentrations of metabolites (G1P, glucose-1-phosphate; G6P, glucose-6-phosphate).R-value was used as measure for meat quality. It describes the degree of desamination ofadenosine and is measured photometrically from the supernatant of muscle homogenates(HONIKEL and FISCHER 1977). Protein content was measured three times. All other traitswere measured twice. The repeatability of G1P was > 0.8, the repeatabilities of all othertraits were > 0.9, similar to literature values (LINDNER 1991).

Statistical analysis

Least square means of the quantitative traits were calculated using the procedure GLMwithin the SAS package version 6.12 (SAS Inc., Cary, NC, USA). The following statisticalmodel was used:

yijk ¼ l þ Gi þ Sj þ ðG � SÞij þ bðAijk � �AAÞ þ eijk

with

yijk : trait value of the ijkth animal,l : general mean,Gi : fixed effect of genetic group i,Sj : fixed effect of sex j,(G*S)ij : effect of interaction of genetic group i and sex j,b(Aijk ) �AA) : linear regression on age at slaughtering,eijk : residual effect.

Phenotypic correlations were also calculated between the residual values after correctionfor the model.

Results and Discussion

Muscle fibres

Table 4 gives the results for the muscle fibre traits. Within the group of Wild Boars, redfibres were the largest, followed by white and intermediate fibres. This is consistent withthe findings of WEILER et al. (1995). In Pietrain and Meishan, as well as in all crossbredgroups, white fibres were largest and intermediate fibres smallest. FEWSON et al. (1993) andRUUSUNEN (1994) also found that white fibres were larger than red and intermediate fibresin domestic pigs. The sizes of muscle fibres were largest in Pietrain (Table 4, Figure 1).BADER (1983), SZENTKUTI et al. (1981) and SZENTKUTI and SCHLEGEL (1985) describedsimilar fibre sizes in Wild Boars, and fibres in Landrace similar to Pietrain in the presentexperiment. In Musculus longissimus dorsi (M.l.d.) of Meishan, BONNEAU et al. (1990) andLAN et al. (1993) measured an average fibre size of about 4000 lm2, which is slightly higherthan the results of our experiment. Selection on muscling seems to increase especially thesizes of white fibres.


Tab

le4.

Mu

scle

fib

retr

aits

(LS

-Mea

ns

±S

E)

Wil

dB

oar

Mei

shan

Pie

trai

nW

ild

Bo

ar·

Pie

trai

nM

eish

an·

Pie

trai

nW

ild

Bo

ar·

Mei

shan

Tra

its

W(a

)n¼

10M

(b)

n¼

66P

(c)

n¼

56F

1(d

)n¼

77F

2(e

)n¼

291

F1

(f)

n¼

88F

2(g

)n¼

309

F1

(h)

n¼

35F

2(i

)n¼

342

Ave

rage

area

(lm

2)

Wh

ite

2666

±46

637

92±

169

8530

±18

041

87±

154

4392

±79

5949

±15

058

36±

7740

70±

239

3629

±73

bcd

efgh

iac

efg

abd

efgh

iac

fgi

abcf

giab

cdef

hi

abcd

ehi

acfg

acd

fgIn

term

edia

te18

26±

330

2595

±12

054

76±

128

2821

±10

929

13±

5637

55±

106

3778

±56

2972

±16

926

21±

52b

cdef

ghi

acef

gab

def

ghi

acfg

abcf

giab

cdeh

iab

cdeh

iac

fgi

acef

ghR

ed27

83±

358

3570

±12

966

31±

138

4032

±11

841

39±

6145

54±

115

4731

±59

3447

±18

432

08±

56b

cdef

gac

def

giab

def

ghi

abcf

ghi

abcf

ghi

abcd

ehi

abcd

ehi

cdef

gb

cdef

gA

vera

ged

iam

eter

(lm

)W

hit

e59

.2±

4.2

69.0

±1.

510

4.9

±1.

674

.1±

1.4

76.4

±0.

787

.4±

1.3

85.8

±0.

770

.6±

2.1

66.5

±0.

6b

cdef

ghac

def

gab

def

ghi

abcf

giab

cfgh

iab

cdeh

iab

cdeh

iac

efg

cdef

gIn

term

edia

te49

.2±

3.8

56.9

±1.

483

.4±

1.5

60.7

±1.

261

.9±

0.6

70.4

±1.

269

.9±

0.6

61.0

±1.

957

.0±

0.6

cdef

ghi

cdef

gab

def

ghi

abcf

giab

cfgi

abcd

ehi

abcd

ehi

acfg

acd

efg

Red

61.6

±3.

768

.3±

1.4

93.7

±1.

473

.9±

1.2

75.6

±0.

679

.5±

1.2

80.1

±0.

666

.4±

1.9

63.7

±0.

6cd

efg

cdef

giab

def

ghi

abcf

ghi

abcf

ghi

abcd

ehi

abcd

ehi

cdef

gb

cdef

gR

elat

ive

no

.o

ffi

bre

s(%

)W

hit

e84

.2±

1.4

82.1

±0.

585

.2±

0.5

86.6

±0.

486

.3±

0.2

84.8

±0.

485

.1±

0.2

83.8

±0.

783

.6±

0.2

cdef

gib

di

bcf

ghi

bfg

hi

bd

eib

dei

de

bcd

efg

Inte

rmed

iate

8.8

±0.

87.

6±

0.3

6.1

±0.

35.

8±

0.3

6.3

±0.

16.

1±

0.3

5.9

±0.

16.

5±

0.4

7.6

±0.

1cd

efgh

cdef

ghab

iab

iab

giab

iab

eiab

icd

efgh

Red

7.0

±0.

910

.3±

0.3

8.5

±0.

47.

5±

0.3

7.4

±0.

29.

0±

0.3

9.0

±0.

29.

7±

0.5

8.7

±0.

1b

fgh

acd

efgi

bd

eb

cfgh

ib

cfgh

iab

de

abd

ead

ed

eR

elat

ive

area

(%)

Wh

ite

85.9

±1.

284

.5±

0.4

88.5

±0.

588

.5±

0.4

88.4

±0.

288

.5±

0.4

88.3

±0.

286

.6±

0.6

86.3

±0.

2cd

efg

cdef

ghi

abh

iab

hi

abh

iab

hi

abh

ib

cdef

gb

cdef

gIn

term

edia

te6.

4±

0.6

5.4

±0.

24.

1±

0.2

4.0

±0.

24.

3±

0.1

4.1

±0.

24.

0±

0.1

5.0

±0.

35.

7±

0.1

cdef

ghcd

efg

abh

iab

hi

abgi

abh

iab

ehi

cdfg

icd

efgh

Red

7.7

±0.

910

.0±

0.3

7.0

±0.

37.

4±

0.3

7.2

±0.

17.

3±

0.3

7.6

±0.

18.

5±

0.4

8.0

±0.

1b

acd

efgh

ib

hi

bh

bh

ib

hi

bh

ib

cdef

gb

cefg

Let

ters

ind

icat

esi

gnifi

can

t(p

<0.

05)

dif

fere

nce

sb

etw

een

the

anim

algr

ou

ps

give

nab

ove


The relative numbers of white fibres were between 82 and 85% in pure-bred groupsof animals (Table 4). Pietrain had the highest proportion of white fibres, followed byWild Boar and Meishan. The different crossbred groups showed slightly higher ratios ofwhite fibres compared to the average of the founder breeds. The relative numbers of redfibres were between 7.0 and 10.3% in the purebred groups. Meishan had the highestpercentage followed by Pietrain and Wild Boar. The relative number of intermediatefibres was highest in Wild Boar, followed by Meishan and Pietrain. F1 and F2 animalsgenerally had values for all fibres between those of the parental groups (Table 4). In thedata presented by RAHELIC and PUAC (1981) and by BADER (1983), numbers of whitefibres in Wild Boar were considerably lower (50%) than in the present experiment(84%). ESSEN-GUSTAVSSON and LINDHOLM (1984) found 73% of white muscle fibres inWild Boar and 85% in Landrace. However, wild boars in our experiment were keptunder housing conditions typical for commercial fattening and this might haveinfluenced relative numbers of different fibre types. The relative numbers of white,intermediate and red fibres of Pietrain were comparable with the data of FEWSON et al.(1993), those of Meishan (Table 4) with data of BONNEAU et al. (1990). Conditions forcommercial fattening in general have caused a high anaerobic potential in muscle fibres.Thus, under the same condition, wild boar and Meishan had muscle fibre profilessignificantly directed to aerobic metabolism as seen from the high relative numbers ofred and intermediate fibres.

All traits were influenced by the genetic group, while sex had only significant influenceson relative areas of white and red fibres. An effect of slaughter age was shown for the whiteand red muscle fibre sizes and diameters. Interaction of genetic group · sex was notsignificant.

As shown in Table 5, the phenotypic correlations were high between parameters offibre sizes and fibre diameters (R ¼ 0.86–0.88) and between relative numbers of fibresand relative areas of fibres within fibre types (R ¼ 0.87–0.90). There were also highlypositive correlations between the sizes of the different fibres (R ¼ 0.74–0.77).

Fig. 1. Structure of muscle fibres of Wild Boar, Meishan and Pietrain


Tab

le5.

Ph

eno

typ

icco

rrel

atio

ns

bet

wee

nth

ed

iffe

ren

tm

usc

lefi

bre

trai

ts

AA

IA

AR

AD

WA

DI

AD

RR

NW

RN

IR

NR

RA

WR

AI

RA

R

Ave

rage

area

of

wh

ite

fib

res

(AA

W)

0.77

c0.

75c

0.88

c0.

66c

0.63

c)

0.23

c0.

10c

0.24

c)

0.03

d0.

01d

0.00

d

Ave

rage

area

of

inte

rmed

iate

fib

res

(AA

I)0.

74c

0.69

c0.

87c

0.63

c)

0.11

c0.

04d

0.12

c)

0.14

c0.

20c

0.02

d

Ave

rage

area

of

red

fib

res

(AA

R)

0.68

c0.

65c

0.86

c)

0.09

b0.

07b

0.05

d)

0.16

c0.

09b

0.13

c

Ave

rage

dia

met

ero

fw

hit

efi

bre

s(A

DW

)0.

78c

0.77

c)

0.23

c0.

08b

0.24

c)

0.05

d0.

02d

0.03

d

Ave

rage

dia

met

ero

fin

term

edia

tefi

bre

s(A

DI)

0.73

c)

0.12

c0.

04d

0.13

c)

0.14

c0.

19c

0.03

d

Ave

rage

dia

met

ero

fre

dfi

bre

s(A

DR

))

0.09

b0.

05d

0.08

b)

0.17

c0.

07b

0.15

c

Rel

ativ

en

um

ber

of

wh

ite

fib

res

(RN

W)

)0.

72c

)0.

80c

0.88

c)

0.63

c)

0.72

c

Rel

ativ

en

um

ber

of

inte

rmed

iate

fib

res

(RN

I)0.

18c

)0.

62c

0.90

c0.

19c

Rel

ativ

en

um

ber

of

red

fib

res

(RN

R)

)0.

70c

0.12

c0.

87c

Rel

ativ

ear

eao

fw

hit

efi

bre

s(R

AW

))

0.67

c)

0.83

c

Rel

ativ

ear

eao

fin

term

edia

tefi

bre

s(R

AI)

0.19

c

a p£

0.05

;bp£

0.01

;c p

£0.

001;

dn

ot

sign

ifica

nt;

RA

R,

rela

tive

area

of

red

fib

res


Correlation-coefficients were similar to the findings of LARZUL et al. (1997) andCANDEK-POTOKAR et al. (1999). Most interestingly, correlations between fibre andcarcass traits were related to diameters of the different fibres within genetic groups(Table 6). Meatiness was higher with increasing fibre diameter in all three fibre types,especially for white fibres, but also for red and intermediate fibres. As given in Table 6,there were only a few, and low, correlations between fibre traits and lean-to-fat ratio andbetween fibre and meat quality traits. A statistically significant decrease in early post-mortem meat quality was correlated with increasing fibre diameters in the Pietrain-basedfamilies, with rising significance from white over intermediate to red fibres. Surprisingly,within the founder breeds, there was a rather inverted tendency compared withcrossbreds as, e.g. between pH 45 and diameters of red fibres. This could partly beexplained by a negative correlation between fibre diameter and lactate production(Table 10).

Table 6. Correlations between fibre traits and meat quality as well as carcass traits

Meat and carcassquality traits Group n

Diameter ofWhite fibres

Intermediatefibres Red fibres

PH45 M.l.d. P 56 0.32a n.s. 0.27a

W, M 76 n.s. 0.28a 0.27a

W · M, F1 + F2 368 0.14b 0.16b 0.12a

W · P, F1 + F2 397 n.s. )0.20a )0.21c

M · P, F1 + F2 378 n.s. n.s. )0.15b

LF45 M.l.d. P 56 )0.30a )0.36c )0.29a

W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 n.s. )0.13a n.s.W · P, F1 + F2 397 n.s. 0.16b 0.22a

M · P, F1 + F2 378 n.s. 0.13b 0.21a

PH24 M.l.d. P 56 0.31c n.s. n.s.W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 n.s. n.s. n.s.W · P, F1 + F2 397 n.s. n.s. n.s.M · P, F1 + F2 378 n.s. n.s. n.s.

LF24 M.l.d. P 56 )0.37c )0.34a )0.30a

W, M 76 )0.25a )0.24a )0.23a

W · M, F1 + F2 368 n.s. )0.13a n.s.W · P, F1 + F2 397 0.15b 0.22c 0.24c

M · P, F1 + F2 378 n.s. 0.18c 0.19c

OPTO P 56 n.s. n.s. n.s.W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 n.s. 0.12a n.s.W · P, F1 + F2 397 )0.15b )0.26c )0.26c

M · P, F1 + F2 378 n.s. n.s. )0.18c

M.l.d.-weight (kg) P 56 n.s. n.s. n.s.W, M 76 0.31b n.s. 0.26a

W · M, F1 + F2 368 0.18c 0.16b 0.14b

W · P, F1 + F2 397 0.41c 0.31c 0.31c

M · P, F1 + F2 378 0.38c 0.29c 0.23c

Lean-to-fat ratio (1:#) P 56 n.s. n.s. n.s.W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 )0.10a n.s. n.s.W · P, F1 + F2 397 n.s. n.s. n.s.M · P, F1 + F2 378 n.s. n.s. n.s.

Correlations are given when statistically significant: ap £ 0.05, bp £ 0.01 or cp £ 0.001; n.s. statistically notsignificant


Tab

le7.

Mu

scle

met

abo

lite

trai

ts(L

S-M

ean

s±

SE

)

Wil

dB

oar

Mei

shan

Pie

trai

nW

ild

Bo

ar·

Pie

trai

nM

eish

an·

Pie

trai

nW

ild

Bo

ar·

Mei

shan

Tra

its

W(a

)n¼

8M

(b)

n¼

66P

(c)

n¼

58F

1(d

)n¼

76F

2(e

)n¼

306

F1

(f)

n¼

93F

2(g

)n¼

310

F1

(h)

n¼

31F

2(i

)n¼

321

R-v

alu

e0.

94±

0.04

0.96

±0.

011.

10±

0.02

1.09

±0.

011.

05±

0.00

1.02

±0.

011.

04±

0.01

0.97

±0.

020.

98±

0.01

cdeg

cdef

gab

efgh

iab

efgh

iab

cdh

ib

cdh

iab

cdh

icd

efg

cdef

gG

lyco

gen

25.5

±3.

719

.8±

1.3

21.2

±1.

318

.4±

1.2

18.7

±0.

619

.9±

1.1

19.6

±0.

621

.3±

2.0

23.5

±0.

6i

ii

ii

bd

efg

G6P

4.5

±0.

82.

4±

0.3

4.9

±0.

32.

5±

0.2

3.0

±0.

13.

1±

0.2

2.8

±0.

13.

2±

0.4

3.1

±0.

1b

dg

acei

bd

efgh

iac

ib

cc

acc

bcd

G1P

0.69

±0.

080.

42±

0.03

0.54

±0.

030.

41±

0.03

0.42

±0.

010.

39±

0.03

0.40

±0.

010.

40±

0.04

0.44

±0.

01b

def

ghi

acb

def

ghi

acac

acac

iac

acg

Lac

tate

47.5

±5.

449

.6±

1.9

72.5

±1.

967

.5±

1.7

61.0

±0.

863

.2±

1.6

61.4

±0.

854

.7±

2.9

52.7

±0.

8cd

efg

cdef

gab

def

ghi

abce

ghi

abcd

hi

abch

iab

cdh

icd

efg

cdef

gG

P10

9.1

±8.

494

.7±

2.9

125.

7±

3.0

110.

2±

2.7

105.

3±

1.3

109.

9±

2.6

107.

0±

1.3

104.

6±

4.5

106.

8±

1.3

cdef

gib

def

ghi

bc

bc

bc

bc

cb

cP

rote

in61

.1±

3.7

61.2

±1.

361

.7±

1.3

61.6

±1.

262

.1±

0.6

66.5

±1.

162

.3±

0.6

63.6

±1.

863

.5±

0.5

ff

ff

bcd

egi

ff

Let

ters

ind

icat

esi

gnifi

can

t(p

<0.

05)

dif

fere

nce

sb

etw

een

the

anim

algr

ou

ps

give

nab

ove

;G

P,

gly

coly

tic

po

ten

tial


Table 8. Phenotypic correlations between the different muscle metabolite traits

Glycogen G6P G1P Lactate GP Protein

R-value ) 0.21c 0.29c 0.13c 0.71c 0.33c 0.05d

Glycogen ) 0.06a ) 0.08b ) 0.25c 0.71c ) 0.01d

G6P 0.38c 0.36c 0.37c 0.02d

G1P 0.20c 0.14c ) 0.10c

Lactate 0.48c 0.02d

GP 0.00d

ap £ 0.05; bp £ 0.01; cp £ 0.001; dstatistically not significant; GP, glycolytic potential

Table 9. Correlations between traits of muscle metabolites and meat quality as well as carcasstraits

Meat and carcassTraits of muscle metabolites

quality traits Group n R-values Lactate Glycolytic potential

PH45 M.l.d. P 56 n.s. n.s. n.s.W, M 76 n.s. )0.33b n.s.W · M, F1 + F2 368 n.s. )0.12a n.s.W · P, F1 + F2 397 )0.45c )0.47c )0.20c

M · P, F1 + F2 378 )0.44c )0.39c )0.28c

LF45 M.l.d. P 56 n.s. n.s. n.s.W, M 76 0.30a n.s. 0.28a

W · M, F1 + F2 368 n.s. n.s. n.s.W · P, F1 + F2 397 0.43c 0.49c 0.30c

M · P, F1 + F2 378 0.39c 0.32c 0.27c

PH24 M.l.d. P 56 n.s. 0.29a n.s.W, M 76 )0.24a n.s. n.s.W · M, F1 + F2 368 n.s. )0.14b n.s.W · P, F1 + F2 397 n.s. n.s. n.s.M · P, F1 + F2 378 n.s. )0.11a )0.24c

LF24 M.l.d. P 56 n.s. n.s. n.s.W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 0.20c 0.22c n.s.W · P, F1 + F2 397 0.46c 0.45c 0.18c

M · P, F1 + F2 378 0.43c 0.34c 0.20c

OPTO P 56 n.s. n.s. n.s.W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 n.s. n.s. n.s.W · P, F1 + F2 397 )0.41c )0.40c )0.19c

M · P, F1 + F2 378 )0.38c )0.35c )0.26c

M.l.d.-weight (kg) P 56 0.27a n.s. n.s.W, M 76 n.s. n.s. )0.24a

W · M, F1 + F2 368 0.11a 0.10a n.s.W · P, F1 + F2 397 n.s. n.s. )0.15b

M · P, F1 + F2 378 )0.21c n.s. )0.11a

Lean-to-fat ratio P 56 n.s. n.s. n.s.W, M 76 n.s. n.s. n.s.W · M, F1 + F2 368 n.s. n.s. n.s.W · P, F1 + F2 397 n.s. n.s. n.s.M · P, F1 + F2 378 n.s. n.s. )0.14b

Correlations are statistically significant with ap £ 0.05; bp £ 0.01; cp £ 0.001; n.s. statistically not significant


Metabolites in skeletal muscle tissue

Pietrain had significantly higher R-values, glycolytic potential (GP) and lactate levels thanWild Boar and Meishan (Table 7). Lactate levels of Pietrain were similar to those of otherdomestic pigs (MULLER 1994; FEDDERN et al. 1995). The values for G1P and G6P in generalwere low, with lowest values in Meishan. The GP as an indicator for the capacity of lactatesynthesis in the skeletal muscle was highest in Pietrain, but the value gives no hint for amutation on the RN-gene (FEDDERN et al. 1994; MONIN and SELLIER 1985; SELLIER 1998).The GP values in Wild Boar and Meishan were low, and the values of the F1 and F2

generations were in the average of those of the founder breeds (Table 7). Protein contentswere similar for the genetic groups.

Lactate and GP values were significantly influenced by sex; G6P values were affected bythe age at slaughter. Interaction between genetic group and sex was found to be significantfor lactate and GP values. In general, environmental effects were low, whereas all traitswere mainly influenced by the genetic group.

Table 8 shows correlations between different muscle metabolites. R-values were closestcorrelated with lactate; GP with glycogen content. Correlation coefficients support thedata of LINDNER (1991) and MULLER (1994), and were slightly lower in the founderbreeds than in the crossbred generations. Similar results have been found by SOSNICKI

(1987), HENCKEL et al. (1997) and LARZUL et al. (1997). Correlations were closer for R-values and lactate, while correlations of the GP and muscle quality traits were weaker.Minor correlations have been found for the glycogen content as well as for the contentsof G6P and G1P (data not shown). As expected, highest correlations could be foundbetween muscle metabolites and traits of the early post-mortem meat quality, withsimilar results reported by MULLER (1994). Correlations between muscle metabolites andcarcass traits were low and often statistically not significant (Table 9), those betweenmuscle metabolites and fibre traits were low (Table 10). Interestingly, in W · Mcrossbreds, positive correlations were observed between fibre diameters and glycogencontent, and negative correlations between fibre diameters and R-value and lactatecontent. In crossbreds based on Pietrain, the correlations between fibre diameters and

Table 10. Correlations between traits of muscle metabolites and fibre characteristics

Muscle metabolites

Fibre traits Group n R-values LactateGlycolyticpotential Glycogen G6P

Diameter of P 56 n.s. n.s. n.s. n.s. n.s.white fibres W, M 76 n.s. n.s. n.s. n.s. )0.31b

W · M, F1 + F2 368 )0.15b )0.17c n.s. 0.24c n.s.M · P, F1 + F2 397 n.s. n.s. n.s. n.s. n.s.W · P, F1 + F2 378 )0.18c )0.16b )0.15b n.s. n.s.

Diameter of P 56 n.s. n.s. n.s. n.s. n.s.intermediate fibres W, M 76 n.s. n.s. n.s. n.s. )0.35b

W · M, F1 + F2 368 )0.13a )0.15b n.s. 0.20c n.s.M · P, F1 + F2 397 0.12a 0.11a n.s. n.s. n.s.W · P, F1 + F2 378 n.s. n.s. n.s. n.s. n.s.

Diameter of P 56 n.s. )0.28a n.s. n.s. n.s.red fibres W, M 76 n.s. n.s. n.s. n.s. )0.30a

W · M, F1 + F2 368 )0.19c )0.15b n.s. 0.18c n.s.M · P, F1 + F2 397 0.11a 0.13a n.s. n.s. n.s.W · P, F1 + F2 378 n.s. n.s. n.s. n.s. n.s.

Correlations are statistically significant with ap £ 0.05; bp £ 0.01; cp £ 0.001; n.s. statistically not significant


R-value and lactate content were (if significant) reciprocal to the W · M crossbreds.FEDDERN et al. (1995) also presented phenotypic correlations between muscle fibrecharacteristics and parameters for post-mortem glycogenolysis measured from biopsysamples of the M. longissimus dorsi. In agreement with our data, they found lowcorrelation coefficients between relative number of fibres and metabolic enzymes (datanot shown). Correlations between fibre sizes and metabolic enzymes have been slightlyhigher.

Summarizing data for correlations between muscle metabolites and performance traits ofmeat and carcass quality, closest correlations occurred in families with segregating Ryr1-alleles (i.e. the crossbred generations). However, some correlations were different betweenfamilies, indicating an influence of further loci linked with the Ryr1-locus or evenindependently inherited loci. The data show a high variability in skeletal muscle fibre traitsand skeletal muscle metabolism, with distinct differences among Pietrain, Wild Boar andMeishan, pointing to genetic regulation behind them. The subsequently QTL-mappingwithin the three families generated from these founder breeds could already analyse thepositions of the responsible genes.

Acknowledgements

This study was part of the PiGMaP project (EC Biotechprogram) and was supported by the ‘DeutscheForschungsgemeinschaft’. The male founder Wild Boar was a generous gift from Prof Dr Scholz (�)(Justus-Liebig-University Giessen, Department of Internal Veterinary Medicine). The Meishan pigsderived from animals kindly provided from Wageningen Agricultural University by Euribrid, BVBoxmeer (the Netherlands). For technical assistance at experimental station ‘Unterer Lindenhof’ wegratefully acknowledge H. Hageloch, H.Muth, G. Clostermann and Coworkers. I. Keiser and Y. Weißdid kindly support the laboratory work.

References

BADER, R., 1983: Vergleichende histometrische und histologische Untersuchungen an der Skelett-muskulatur von Wild- und Hausschweinen. Berl. Munch. Tierarztl. Wschr. 96: 89–97.

BERGMEYER, H. U., 1974: Methoden der Enzymatischen Analyse. Verlag Chemie, Weinheim.BEYERSDORFER, G.; OHLERICH, M.; WEGNER, J., 1985: Ein halbautomatisches Meßgerat zur

Morphometrie von Muskelfasern im mikroskopischen Querschnittpraparat. Z. Mikroskop. Anat.Forsch. 99: 671–675.

BONNEAU, M.; MOUROT, J.; LEFAUCHER, L.; BIDANEL, J. P., 1990: Tissue development in Meishan pigs:Muscle and fat development and metabolism and growth regulation by somatotropic hormone.Symposium sur le porc chinois. Proceedings of the Symposium Sur le Porc Chinois; Toulouse 5–6July 1990 (Ed. by M. MOLENAT; C. LEGAULT). INRA, 203–213.

CANDEK-POTOKAR, M.; LEFAUCHEUR, L.; ZLENDER, B.; BONNEAU, M., 1999: Effect of slaughter weightand/or age on histological characteristics of pig longissimus dorsi muscle as related to meatquality. Meat Sci. 52: 195–203.

ESSEN-GUSTAVSSON, B., 1993: Muscle-fiber characteristics in pigs and relationships to meat-qualityparameters. In: Pork Quality: Genetic and Metabolic Factors (Ed. by E. POULANNE, D. I.DEMEYER, M. RUUSUNEN, S. ELLIS). CAB International, Wallingford, UK, 140-159.

ESSEN-GUSTAVSSON, B.; LINDHOLM, A., 1984: Fiber types and metabolic characteristics in muscles ofwild boars, normal and halothane sensitive Swedish Landrace pigs. Comp. Biochem. Physiol. 78A:67–71.

FEDDERN, E.; KRIETER, J.; KALM, E., 1994: Verlauf der postmortalen Glykogenolyse und Merkmale derFleischbeschaffenheit bei Hampshire Reinzuchttieren und verschiedenen Kreuzungskombinatio-nen. Arch. Tierz. Dummersdorf. 37: 229–243.

FEDDERN, E.; WEGNER, J.; ENDER, K.; KALM, E., 1995: Untersuchungen von Muskelstrukturmerk-malen bei Hampshire Reinzuchttieren und verschiedenen Kreuzungskombinationen. Arch. Tierz.Dummersdorf. 38: 43–56.

FEWSON, D.; RATHFELDER, A.; MULLER. E., 1993: Untersuchungen uber die Beziehungen vonFleischanteil, Fleischbeschaffenheit und Stressresistenz bei verschiedenen Schweineherkunften. 1.Mitt.: Bedeutung der Morphologie des M. longissimus dorsi. Zuchtungskunde 65: 284–296.

FIEDLER, I.; REHFELDT, C.; ALBRECHT, E.; HENNING, M., 1998: Histophysiological features of skeletalmuscle and adrenal glands in wild-type and domestic pigs during growth. Arch. Tierz. 41:489–495.


GELDERMANN, H.; MULLER, E.; BEEKMANN, P.; KNORR, C.; YUE, G.; MOSER, G., 1996: Mapping ofquantitative-trait loci by means of marker genes in F2-generations of Wild boar, Pietrain andMeishan pigs. J. Anim. Breed. Genet. 113: 381–387.

HENCKEL, P.; OKSBJERG, N.; ERLANDSEN, E.; BARTON-GADE, P.; BEJERHOLM, C., 1997: Histo- andbiochemical characteristics of the Longissimus dorsi muscle in pigs and their relationships toperformance and meat quality. Meat Sci. 47: 311–321.

HONIKEL, K. O.; FISCHER, CH., 1977: Eine Schnellmethode zur Bestimmung von PSE- und DFD-Fleisch beim Schwein. Fleischwirtsch. 57: 1015–1017.

LAN, Y. H.; MCKEITH, F. K.; NOVAKOFSKI, J.; CARR, T. R., 1993: Carcass and muscle characteristics ofYorkshire, Meishan, Yorkshire · Meishan, Meishan · Yorkshire, Fengjing · Yorkshire, andMinzhu · Yorkshire pigs. J.Anim. Sci. 71: 3344–3349.

LARZUL, C.; LAFAUCHEUR, L.; ECOLAN, P.; GOGUE, J.; TALMANT, A.; SELLIER, P.; LE ROY, P.; MONIN,G., 1997: Phenotypic and genetic parameters for longissimus muscle fiber characteristics inrelation to growth, carcass, and meat quality traits in Large White pigs. J. Anim. Sci. 75:3126–3137.

LINDNER, R., 1991: Untersuchungen uber die Beziehungen zwischen Glykolyse und Fleischbe-schaffenheit beim Schwein – zugleich Beschreibung der Basis eines Selektionsexperimentes. Diss.Universitat Hohenheim.

LOWRY, O. H.; ROSEBROUCH, N. J.; FARR, A. L.; RANDALL, R. J., 1951: Protein measurement with theFolin-phenol-reagent. J. Biol. Chem. 193: 265–275.

MONIN, G.; SELLIER, P., 1985: Pork of low technological quality with a normal rate of muscle pH fallin the immediate post-mortem period: the case of the Hamshire breed. Meat Sci. 13: 49–63.

MULLER, E., 1994: Untersuchungen uber die Beziehungen von Fleischanteil, Fleischbeschaffenheit undStressresistenz bei verschiedenen Schweineherkunften. II. Mitteilung: Vergleich von Enzymakti-vitaten und Metabolitkonzentrationen des Glykogenabbaus im M. longissimus dorsi.Zuchtungskunde 66: 349–358.

RAHELIC, S.; PUAC, S., 1981: Fibre types in Longissimus dorsi from wild and highly selected pig breeds.Meat Sci. 5: 439–450.

REDE, R.; PRIBISCH, V.; RAHELIC, S., 1986: Untersuchungen uber die Beschaffenheit vonSchlachttierkorpern und Fleisch primitiver und hochselektierter Schweinerassen. Fleischwirtsch.66: 898–907.

RUUSUNEN, M., 1994: Muscle histochemical properties of different pig breeds in relation to meatquality. Diss. University of Helsinki.

SCHWAGELE, F.; HASCHKE, C.; HONIKEL, K. O.; KRAUSS, G., 1996a: Enzymological investigations onthe causes for the PSE syndrome, I. Comparative studies on Pyruvate Kinase from PSE- andnormal pig muscles. Meat Sci. 44: 27–40.

SCHWAGELE, F.; BUESA, P. L.; HONIKEL, K. O., 1996b: Enzymological investigations on the causes forthe PSE-syndrome, I. Comparative studies on Glycogen Phosphorylase from pig muscles. MeatSci. 44: 41–53.

SELLIER, P., 1998: Genetics of meat and carcass traits. In: The Genetics of the Pig (Ed. by M. F.ROTHSCHILD, A. RUVINSKY). CABI, Wallingford, UK, 463–510.

SOSNICKI, A., 1987: Association of micrometric traits on meat quality, fattening and slaughter traits inpig. J. Anim. Sci. 64: 1412–1418.

SZENTKUTI, L.; EGGERS, A., 1985: Eine zuverlassige Modifikation der Myosin-ATPase-Reaktion zurhistochemischen Darstellung von drei Fasertypen in der Skelettmuskulatur von Schweinen.Fleischwirtsch. 65: 1398–1404.

SZENTKUTI, L.; NIEMEYER, B.; SCHLEGEL, O., 1981: Vergleichende Untersuchung von Muskelfaser-typen mit der Myosin-ATPase-Reaktion im M. longissimus dorsi von Haus- und Wildschweinen.Dtsch. Tierarztl. Wschr. 88: 407–411.

SZENTKUTI, L.; SCHLEGEL, O., 1985: Genetische und funktionelle Einflusse auf Fasertypenanteile undFaserdurchmesser im M. longissimus dorsi und M. semitendinosus von Schweinen. Untersuch-ungen an trainierten Haus- und immobil gehaltenen Wildschweinen. Dtsch. Tierarztl. Wschr. 92:93–97.

WEILER, U.; APPELL, H.-J.; KREMSER, M.; HOFACKER, S.; CLAUS, R., 1995: Consequences of selectionon muscle composition. A comparative study on gracilis muscle in wild and domestic pigs. Anat.Histol. Embryol. 24: 77–80.


fibre structure and metabolites in m. longissimus dorsi of wild boar, pietrain and meishan pigs as...

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