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
Histochemical
Histochemical properties and meat quality traits of properties and meat quality traits of porcine muscles during growth:
porcine muscles during growth:
Effect of feed restriction in pigs slaughtered at the same Effect of feed restriction in pigs slaughtered at the same weight and varying age
weight and varying age
G. Bee, M. Calderini, C. Biolley, G. Guex, W. Herzog G.
G. Bee, Bee , M. M. Calderini Calderini, C. , C. Biolley Biolley, G. , G. Guex Guex, W. Herzog , W. Herzog
Agroscope Liebefeld-Posieux, Swiss Federal Research Station for Animal Production and Dairy Products (ALP) Agroscope
Agroscope Liebefeld Liebefeld- -Posieux Posieux, , Swiss Federal Research Station for Animal Production and Dairy P Swiss Federal Research Station for Animal Production and Dairy Pr
SO FOG FG
muscle fiber type distribution (%)
0 20 40 60 80
A60 R60 A100 R100 d c d c
a b a b
SO FOG FG
muscle fiber type distribution (%)
0 20 40 60 80
A60 R60 A100 R100 a b a a
c c d d
A)
B)
LD STL
Shear force values (kg)
0 1 2 3 4 5 6
A60 R60 A100 R100 c d c c
a b a b
LD STL
Cooking loss (%)
0 5 10 15 20 25 30
A60 R60 A100 R100 b b a a
a b a b
A)
B)
SO fiber size (µm2) 2000 3000 4000 5000 6000 7000 8000
shear force values (kg)
1 2 3 4 5 6 7
LM STL r = -0.44
FOG fiber size (µm2) 2000 3000 4000 5000 6000 7000 8000
shear force values (kg)
1 2 3 4 5 6 7
LM STL r = -0.41
FG fiber size (µm2) 2000 3000 4000 5000 6000 7000 8000
shear force values (kg)
1 2 3 4 5 6 7
LM STL r = -0.33
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 LMLMand light portion of thelight portion of thesemitendinosussemitendinosusmusclemuscle.
Effect of feed intake on muscle fiber type distribution of the LM (A) and STL (B) of pigs slaughtered at 61 kg (A60and R60) or 101 kg BW (A100and 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.
Effect of feed intake on cooking loss (A) and shear force values determined in the LM and STL of pigs slaughtered at 61 kg (A60and R60) or 101 kg BW (A100and R100). Different superscripts denote differences between treatment groups within each muscle (a,b; P <
0.05; c,d; P < 0.10).
Material and Methods Material and Methods
Animals and TreatmentsTwenty-four Swiss Large White barrows from six 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 (A60A60;
n = 6 and R60R60; n = 6) or 101.3 ±1.48 kg BW (A100A100; n = 6 and R100R100; n = 6).
Tissue sampling at slaughter Muscle samples were collected within 40 min postmortem
Histochemical AnalysisMuscle sections were treated with the combination of succinic dehydrogenase and acid myofibrillar ATPase according to the multiple staining procedure of Solomon and Dunn (1988).
Morphometric Muscle Measurements and Meat Quality Traits
SO SO slow oxidative slow oxidative FOG FOG fast oxidative fast oxidative--glycolyticglycolytic
FG FG fast fastglycolyticglycolytic
LM muscle fiber type STL
STL
LM
Drip, thaw, and cooking loss
Shear force value Weight of the
semitendinosus muscle LM area
area (cm2)
0 10 20 30 40 50 60 70
A60 R60 A100 R100
weight (g)
0 100 200 300 400 500
A60 R60 A100 R100 b
a a b
d
a b c
A)
B)
Effect of feed intake on loin area (A) and weight of the semitendinosus muscle (B) of pigs slaughtered at 61 kg (A60and R60) or 101 kg BW (A100and R100). Different superscripts denote differences between treatment groups (P < 0.05).
oducts roducts (ALP) (ALP)
SO FOG FG
area (µm2)
0 1000 2000 3000 4000 5000
A60 R60 A100 R100 a a
b b a a
b b
SO FOG FG
area (µm2)
0 1000 2000 3000 4000 5000 6000
A60 R60 A100 R100 a a
b b a a
b b a a
b b
A)
B)
Effect of feed intake on muscle fiber size of the LM (A) and STL (B) of pigs slaughtered at 61 kg (A60and R60) or 101 kg BW (A100and 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.
Introduction Introduction
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).
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.
Objectives 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).
Conclusions Conclusions
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 References
Candek-Potokar, M., L. Lefaucheur, B. Zlender, and M. Bonneau. 1999. Effect of slaughter weight and/or age on histochemical characteristics of piglongissimus 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.
Joint Annual Meeting 2005/ Cincinnati, Ohio/July 22 – 28
Corresponding author: Giuseppe Bee, Agroscope Liebefeld-Posieux, giuseppe.bee@alp.admin.ch
