Histochemical properties and meat quality traits of
porcine muscles during growth:
Effect of feed restriction in pigs slaughtered at the same
weight and varying age
G.
G. Bee,
Bee,, M.
M. Calderini,
Calderini,, C.
C. Biolley,
Biolley,, G. Guex,
Herzog
Bee
Calderini
Biolley
Guex, W. Herzog
Agroscope
Agroscope LiebefeldLiebefeld-Posieux,
-Posieux,
Swiss Federal
Federal Research
Research Station
Station for
for Animal
Animal Production
Production and
and Dairy
Dairy Pr
Products
(ALP)
Liebefeld
Posieux, Swiss
P
roducts
oducts (ALP)
Introduction
70
In pigs the number of muscle fibers is determined at birth (Stickland
and Goldspink, 1973). Thus, during postnatal growth increase in
skeletal muscle mass is mainly a result of an increase in muscle
fiber size (hypertrophic growth). At birth, all fibers are oxidative and
an intense conversion towards glycolytic fibers is observed up to 4
months of age. Thereafter, the proportion of glycolytic fibers keeps
on increasing but at a much slower rate (Lefaucheur and Vigneron,
1986).
min postmortem
LM
2
1000
0
SO
B)
6000
c d
A60
R60
A100
R100
a b
200
a a
A60
R60
A100
R100
3000
2000
SO
30
a b
25
60
A60
R60
A100
R100
40
20
d c
b b
20
A60
R60
A100
R100
15
10
5
SO
FOG
0
FG
B)
6
d d
B)
LD
c d
STL
c c
c c
60
A60
R60
A100
R100
40
a b
20
a a
0
FOG
a b
5
4
A60
R60
A100
R100
3
2
1
LD
7
LM
STL
r = -0.41
shear force values (kg)
6
4
3
4
3
2
1
1
3000
4000
5000
6000
2
SO fiber size (µm )
7000
8000
LM
STL
r = -0.33
6
5
2
2000
Morphometric Muscle Measurements and Meat Quality Traits
STL
Effect of feed intake on cooking loss (A) and shear force values
determined in the LM and STL of pigs slaughtered at 61 kg (A60 and
R60) or 101 kg BW (A100 and R100). Different superscripts denote
differences between treatment groups within each muscle (a,b; P <
0.05; c,d; P < 0.10).
7
5
a b
0
FG
LM
STL
r = -0.44
FG
fast glycolytic
a b
a a
d c
0
shear force values (kg)
A)
5
4
3
2
FOG
fast oxidativeoxidative-glycolytic
FG
a b
Cooking loss (%)
muscle fiber type distribution (%)
A)
a b
FOG
Effect of feed intake on muscle fiber size of the LM (A) and STL (B)
of pigs slaughtered at 61 kg (A60 and R60) or 101 kg BW (A100 and
R100). Different superscripts denote differences between treatment
groups within each fiber type (a,b; P < 0.05). SO = slow oxidative;
FOG = fast oxidative-glycolytic; FG = fast glycolytic.
Effect of feed intake on loin area (A) and weight of the
semitendinosus muscle (B) of pigs slaughtered at 61 kg (A60 and
R60) or 101 kg BW (A100 and R100). Different superscripts denote
differences between treatment groups (P < 0.05).
6
slow oxidative
4000
0
7
STL
b b
a a
1000
0
of succinic dehydrogenase and acid myofibrillar ATPase according to the
multiple staining procedure of Solomon and Dunn (1988).
SO
b b
b b
2
area (µm )
300
100
Histochemical Analysis Muscle sections were treated with the combination
muscle fiber type
FG
a a
Effect of feed intake on muscle fiber type distribution of the LM (A)
and STL (B) of pigs slaughtered at 61 kg (A60 and R60) or 101 kg
BW (A100 and R100). Different superscripts denote differences
between treatment groups within each fiber type (a,b; P < 0.05; c,d; P <
0.10). SO = slow oxidative; FOG = fast oxidative-glycolytic; FG = fast
glycolytic.
STL
FOG
B)
400
SO
LM
area (µm )
area (cm2)
20
A60
R60
A100
R100
2000
shear force values (kg)
Tissue sampling at slaughter Muscle samples were collected within 40
30
a a
a a
3000
Shear force values (kg)
n = 6 and R60;
A100; n = 6 and R100;
R60 n = 6) or 101.3 ± 1.48 kg BW (A100
R100 n = 6).
A60
R60
A100
R100
a a
40
5000
muscle fiber type distribution (%)
litters were selected and had either restricted (R) or ad libitum (A) or access to a
standard growing (20 – 60 kg BW) and finishing (60 – 100 kg BW) diet. Two
littermates from two dietary treatments were slaughtered at 61.3 ± 0.99 kg (A60
A60;
50
500
80
Material and Methods
b b
b b
0
80
Animals and Treatments Twenty-four Swiss Large White barrows from six
A)
4000
10
Objectives
The purpose of this experiment was to compare the histochemical
properties of myofibers and meat quality traits in two glycolytic
muscles (LM and light portion of the semitendinosus muscle [STL])
in pigs with restricted (80% of voluntary feed intake) or ad libitum
access to feed. Pigs were slaughtered either at the end of the
growing or finishing period at the same BW but different age. The
BW at slaughter was chosen based on the results obtained by
Lefaucheur and Vigneron (1986), who showed that the rate of
conversion from oxidative towards glycolytic metabolism is slowed
down after 60 kg BW (< 4 months of age).
5000
b b
60
weight (g)
Postnatal nutrition is one of the determinant factors influencing
muscle development through their effects on growth rate and body
composition. Harrison et al. (1996) reported significantly reduced
muscle fibers size and concomitantly higher proportions of slow
oxidative fibers (SO) in 2 month old pigs after sever dietary energy
restriction (50% of ad libitum). However, the reduction in fiber size
was accompanied by a reduction in body weight. When muscle fiber
size is compared at a similar BW (100 or 130 kg), muscle fiber type
distribution was not affected and only SO fibers tended to be smaller
in pigs with restricted (70% of voluntary feed intake) compared to ad
libitum feed allowance (Čandek-Potokar et al., 1999). By contrast, in
younger and lighter pigs (50 kg BW at slaughter) Solomon et al.
(1988) reported smaller SO and smaller fast glycolytic fibers (FG) as
well as higher proportions of fast oxidative-glycolytic fibers (FOG)
and lower proportions of FG fibers in restrictively fed pigs compared
to pigs with ad libitum access to the diet.
A)
1
2000
3000
4000
5000
6000
2
FOG fiber size (µm )
7000
8000
2000
3000
4000
5000
6000
7000
8000
2
FG fiber size (µm )
Relationship between the size of SO (slow oxidative), FOG (fast oxidative-glycolytic), and FG (fast glycolytic) fibers and the shear force values
determined in the LM and light portion of the semitendinosus muscle.
muscle
Conclusions
LM area
Weight of the
semitendinosus muscle
Drip, thaw, and cooking loss
Shear force value
Feed restriction (effect of age at a given weight) had no effect on myofiber size of the LM and STL. Compared to the ad
libitum group, the LM but not the STL of pigs with restricted feed allowance had more FG and fewer SO fibers. This
finding suggests a greater maturation rate of this muscle with increasing age. Although the number of FG fibers
increased from 60 to 100 kg BW in the STL, age (at the same BW) seemed not to affect STL maturation. This might be
explained by the lower allometric growth rate of the semitendinosus muscle compared to the LM.
The STL of pigs in the restricted group displayed higher cooking losses and was less tender compared to the STL of
pigs in the ad libitum group. Furthermore, with increasing size of SO, FOG, and FG fibers shear force values
decreased. This relationship resulted mainly from the higher shear force values and smaller myofibers observed in pigs
at 60 kg BW than in pigs at 100 kg BW.
References
Joint Annual Meeting 2005 / Cincinnati, Ohio / July 22 – 28
Corresponding author: Giuseppe Bee,
Agroscope Liebefeld-Posieux, giuseppe.bee@alp.admin.ch
Candek-Potokar, M., L. Lefaucheur, B. Zlender, and M. Bonneau. 1999. Effect of slaughter weight and/or age on histochemical characteristics of pig longissimus dorsi muscle as
related to meat quality. Meat Sci. 52:195-203. Harrison, A. P., A. M. Rowlerson, and M. J. Dauncey. 1996. Selective regulation of myofiber differentiation by energy status during
postnatal development. AJP 270:R667-R674. Lefaucheur, L. and P. Vigneron. 1986. Postnatal changes in some histochemical and enzymatic characteristics of three pig muscles.
Meat Sci. 16:199-216. Solomon, M. B., R. G. Campbell, N. C. Steele, T. J. Caperna, and J. P. McMurtry. 1988. Effect of Feed-Intake and Exogenous Porcine Somatotropin on
Longissimus Muscle-Fiber Characteristics of Pigs Weighing 55 Kilograms Live Weight. J. Anim. Sci. 66:3279-3284. Stickland, N. C. and G. Goldspink. 1973. A possible indicator
muscle for the fibre content and growth characteristics of porcine muscle. Anim. Prod. 16:135-146.