Table 1. Summary of results on muscle fiber characteristics of porcine skeletal muscle reported in previous studies1)

Breed Sex Age (day) Weight (kg) Muscles Typing method Muscle fiber characteristics1) References
Type CSA Area % Number % Density
Yorkshire Female 170 (L) 100 M. longissimus thoracis et lumborum ISH I - - 10.9 - [12]
I/IIA - - 0.1 -
IIA - - 6.7 -
IIA/IIX - - 0.3 -
IIB - - 62.3 -
IIX - - 17.5 -
IIX/IIB - - 2.2 -
mATPase I - - 11.0 -
IIA - - 7.0 -
IIB - - 82.0 -
M. rhomiboide ISH I - - 68.0 -
I/IIA - - - -
IIA - - 12.0 -
IIA/IIX - - - -
IIB - - - -
IIX - - 20.0 -
IIX/IIB - - - -
mATPase I - - 68.0 -
IIA - - 12.0 -
IIB - - 20.0 -
LYD Male Female 185 (L) 105 M. longissimus thoracis mATPase I 4,226 12.5 12.7 29.7 [25]
IIA 4,204 9.4 9.9 22.9
IIB 4,624 78.1 77.4 183.4
Yorkshire Male - (L) 101 M. longissimus thoracis et lumborum mATPase I 2,376 6.8 9.6 - [26]
IIA 1,751 3.3 6.2 -
IIBr 2,483 7.5 10.0 -
IIBw 3,666 82.4 74.3 -
SDH I 2,415 6.5 9.5 -
IIA 1,868 3.5 6.6 -
IIBr 2,616 7.5 10.0 -
IIBw 3,940 82.5 73.9 -
Berkshire Male Female 172.7 (C) 77.75 M. longissimus thoracis et lumborum mATPase I - 7.5 10.7 - [27]
IIA - 5.8 9.0 -
IIB - 85.0 80.3 -
Landrace (C) 77.75 I - 6.2 9.1 -
IIA - 5.6 9.4 -
IIB - 88.2 81.5 -
LYD (C) 81.85 I - 5.4 8.1 -
IIA - 7.1 12.4 -
IIB - 87.5 79.4 -
Yorkshire (C) 75.4 I - 6.8 8.9 -
IIA - 6.4 10.6 -
IIB - 86.8 80.5 -
LYD Male - (C) 78.5 M. longissimus thoracis IHC I 2,743 6.2 12.9 - [9]
IIA 3,052 3.4 6.1 -
IIA/IIX 4,765 0.4 0.6 -
IIB 6,114 68.1 63.1 -
IIX 6,869 17.6 14.6 -
IIX/IIB 8,251 4.4 3.1 -
M. psoas major I 2,375 18.5 23.5 -
IIA 2,166 20.4 28.1 -
IIA/IIX - - - -
IIB 4,191 32.4 23.2 -
IIX 3,409 28.8 25.2 -
IIX/IIB - - - -
M. semimembranosus I 3,055 6.3 12.0 -
IIA 3,011 4.7 8.6 -
IIA/IIX 6,631 2.9 2.6 -
IIB 6,997 79.3 65.4 -
IIX 3,634 7.2 11.4 -
IIX/IIB 4,520 2.3 2.9 -
M. semitendinosus I 4,866 23.9 26.7 -
IIA 4,468 14.1 17.0 -
IIA/IIX 4,992 1.6 1.7 -
IIB 6,282 29.7 25.7 -
IIX 5,407 24.8 24.7 -
IIX/IIB 7,479 6.0 4.3 -
Berkshire - - (L) 110 M. longissimus thoracis et lumborum mATPase I 3,302 6.5 - 20.0 [28]
IIA 2,801 9.4 - 34.0
IIB 4,398 84.1 - 194.0
Duroc I 3,025 6.1 - 20.0
IIA 3,014 9.1 - 30.0
IIB 5,133 84.9 - 170.0
Landrace I 2,933 6.5 - 22.0
IIA 2,781 7.6 - 27.0
IIB 4,987 86.0 - 177.0
Yorkshire I 3,031 6.9 - 23.0
IIA 2,698 8.3 - 31.0
IIB 5,050 84.8 - 173.0
KNP and Landrace Male Female 203 (C) 89.2 M. longissimus thoracis et lumborum mATPase I 3,877 9.1 12.1 - [6]
IIA 3,989 8.3 11.3 -
IIB 4,843 80.8 77.2 -
Berkshire Male - - M. longissimus thoracis et lumborum IHC SDH ISH I - 9.8 10.19 - [24]
IIA - 4.0 3.61 -
IIB - 54.8 55.70 -
IIX - 29.8 29.96 -
M. psoas major I - 11.9 12.31 -
IIA - 10.6 10.20 -
IIB - 41.7 42.58 -
IIX - 41.6 41.69 -
Duroc M. longissimus thoracis et lumborum I - 14.5 11.40 -
IIA - 3.4 4.03 -
IIB - 52.8 52.36 -
IIX - 29.6 34.71 -
M. psoas major I - 14.7 8.54 -
IIA - 15.0 8.67 -
IIB - 39.5 50.62 -
IIX - 39.8 33.01 -
Tamworth Male - - M. longissimus thoracis et lumborum IHC SDH ISH I - 12.3 14.69 - [24]
IIA - 5.9 3.16 -
IIB - 49.2 51.85 -
IIX - 32.3 29.64 -
M. psoas major I - 12.1 14.62 -
IIA - 7.6 14.76 -
IIB - 38.2 40.13 -
IIX - 41.5 39.36 -
Yorkshire M. longissimus thoracis et lumborum I - 12.1 12.87 -
IIA - 3.7 6.13 -
IIB - 51.3 49.68 -
IIX - 35.6 31.44 -
M. psoas major I - 9.2 12.74 -
IIA - 8.4 7.81 -
IIB - 49.5 38.65 -
IIX - 33.9 40.71 -
KNP and Landrace Male Female 190 (C) 79.85 M. longissimus thoracis et lumborum IHC I 4,797 8.6 - 21.6 [29]
IIA 4,242 7.6 - 16.8
IIA/IIX 4,494 3.6 - 5.3
IIB 5,601 58.8 - 99.2
IIX 6,823 19.5 - 33.5
IIX/IIB 7,566 7.4 - 8.2
Domestic pig Male Female 165 (C) 81 M. gluteus superficialis mATPase I 2,880 6.8 - - [30]
IIA 3,420 4.0 - -
IIB 5,940 89.3 - -
M. infra spinam I 4,780 53.0 - -
IIA 5,390 19.7 - -
IIB 5,780 27.3 - -
M. longissimus thoracis et lumborum I 2,950 6.5 - -
IIA 2,750 3.2 - -
IIB 5,790 90.3 - -
M. masseter I 2,700 22.5 - -
IIA 2,850 70.8 - -
IIB 2,450 6.7 - -
M. semimembranosus I 3,050 6.6 - -
IIA 3,480 3.6 - -
IIB 6,210 89.8 - -
Wild pig M. gluteus superficialis I 4,070 17.9 - -
IIA 3,430 16.4 - -
IIB 4,760 65.8 - -
M. infra spinam I 4,450 55.3 - -
IIA 4,230 33.5 - -
IIB 4,740 11.3 - -
M. longissimus thoracis et lumborum I 3,400 13.0 - -
IIA 2,900 17.3 - -
IIB 3,740 69.7 - -
M. masseter I 3,240 68.0 - -
IIA 2,700 28.7 - -
IIB 2,410 3.3 - -
M. semimembranosus I 3,890 16.6 - -
IIA 3,230 16.1 - -
IIB 3,760 67.3 - -
Polish Large White Female 176 (C) 78.8 M. longissimus lumborum IHC I 2,516 4.9 8.2 18.0 [31]
IIA 2,485 9.5 15.0 33.0
IIB 4,658 85.6 76.9 167.0
Puławska Female 198 (C) 76.34 I 2,752 8.9 11.6 27.0
IIA 2,547 11.7 16.3 38.0
IIB 3,926 79.4 72.1 169.0
YLD - - (C) 79.2 M. longissimus thoracis et lumborum mATPase I - 5.7 8.4 - [32]
IIA - 7.7 13.4 -
IIB - 86.6 78.2 -
LYD Male - (C) 79.2 M. biceps brachii IHC I 2,669 16.7 - 56.5 [3]
IIA 1,965 20.5 - 105.0
IIA/IIX 1,802 3.6 - 17.7
IIB 2,656 10.8 - 36.9
IIX 2,625 32.4 - 121.9
IIX/IIB 2,267 16.0 - 65.8
M. biceps femoris I 3,040 28.1 - 92.0
IIA 2,192 14.1 - 65.9
IIA/IIX 1,286 1.0 - 7.6
IIB 2,905 32.1 - 114.0
IIX 2,898 17.6 - 65.9
IIX/IIB 2,019 7.1 - 29.1
M. diaphragm I 2,062 43.2 - 210.7
IIA 1,654 33.0 - 200.7
IIA/IIX - - - -
IIB 2,609 5.7 - 23.2
IIX 1,960 10.1 - 51.8
IIX/IIB 1,859 8.1 - 43.5
M. gracilis I 4,095 15.9 - 38.9
IIA 3,937 13.1 - 32.9
IIA/IIX 4,462 1.0 - 2.2
IIB 3,897 9.7 - 26.1
IIX 4,043 50.6 - 128.7
IIX/IIB 2,968 9.7 - 33.1
M. infrahyoid I 4,404 49.4 - 111.8
IIA 3,981 33.2 - 83.5
IIA/IIX - - - -
IIB - - - -
IIX 4,042 9.4 - 23.6
IIX/IIB 4,284 8.0 - 19.5
M. longissimus thoracis et lumborum I 1,937 4.2 - 21.9
IIA 1,107 11.2 - 102.5
IIA/IIX - - - -
IIB 1,719 42.2 - 242.8
IIX 1,802 26.4 - 152.0
IIX/IIB 2,010 15.9 - 79.0
M. psoas major I 4,050 21.5 - 49.8
IIA 3,834 26.5 - 71.3
IIA/IIX 3,399 2.0 - 5.0
IIB 4,171 10.7 - 24.2
IIX 3,886 14.5 - 42.3
IIX/IIB 4,578 24.4 - 57.7
LYD Male - (C) 79.2 M. rectus abdominis IHC I 3,803 49.4 - 135.2 [3]
IIA 2,838 19.8 - 74.3
IIA/IIX 3,312 2.3 - 6.9
IIB 2,932 3.1 - 9.4
IIX 3,761 18.1 - 43.9
IIX/IIB 3,104 7.4 - 23.3
M. rectus femoris I 2,302 14.8 - 63.6
IIA 1,791 21.0 - 113.2
IIA/IIX 1,971 0.9 - 4.7
IIB 2,921 32.7 - 112.3
IIX 2,518 11.2 - 44.8
IIX/IIB 2,902 18.6 - 65.7
M. semimembranosus I 2,757 15.3 - 57.6
IIA 1,817 5.8 - 34.3
IIA/IIX 1,857 2.7 - 15.1
IIB 3,167 51.0 - 157.7
IIX 2,268 22.9 - 102.3
IIX/IIB 2,765 2.3 - 8.9
M. semitendinosus I 3,551 3.0 - 8.3
IIA 2,096 18.5 - 59.7
IIA/IIX - - - -
IIB 2,736 32.0 - 116.5
IIX 3,259 26.8 - 82.9
IIX/IIB 3,246 19.7 - 59.2
M. subcapularis I 3,150 23.9 - 73.8
IIA 2,850 18.6 - 66.0
IIA/IIX 2,847 1.3 - 4.8
IIB 3,569 16.7 - 46.7
IIX 3,519 27.7 - 77.4
IIX/IIB 3,523 11.7 - 34.8
M. superficialis digital flexor I 3,329 29.3 - 80.8
IIA 2,492 23.1 - 93.6
IIA/IIX 2,489 2.0 - 8.0
IIB 2,355 18.3 - 72.0
IIX 1,705 13.3 - 58.7
IIX/IIB 2,190 14.0 - 60.2
M. vastus I 1,995 10.3 - 52.9
IIA 1,577 17.5 - 113.2
IIA/IIX 1,795 2.9 - 17.6
IIB 2,747 25.4 - 101.3
IIX 2,835 21.3 - 86.4
IIX/IIB 2,750 22.6 - 81.0
LYD - - (C) 82.5 M. longissimus thoracis IHC I 2,977 6.4 10.3 - [33]
IIA 2,709 5.5 9.6 -
IIB 5,490 75.1 66.0 -
IIX 4,439 12.9 13.7 -
LYD - - (L) 132.9 M. longissimus thoracis IHC I 3,129 6.3 10.3 - [34]
IIA 2,853 5.3 9.4 -
IIB 5,682 75.3 66.4 -
IIX 4,895 13.0 13.9 -
Data expressed as ranges in previous studies are presented as average values.
CSA, cross-sectional area (µm2); Area%, relative fiber area (%); Number%, relative fiber number (%); Density, fiber density (number/mm2).
L, Live weight; ISH, in situ hybridization; mATPase, myosin ATPase; LYD, crossbred of (Landrace x Yorkshire) x Duroc; SDH, Succinic dehydrogenase; C, Carcass weight; IHC, immunohistochemistry; KNP, Korean native black pig; YLD, crossbred of (Yorkshire x Landrace) x Duroc.