New Insights into Muscle Fibre Types in Casertana Pig

Abstract

Little is known about the Casertana pig. The aim of this study was to evaluate the effect of sex on histochemical and morphometrical characteristics of muscle fibres (myocytes) in this pure breed and to verify the presence of giant fibres as well as vascularity of the muscle. Finally, maximum shortening velocity and isometric tension were measured in single muscle fibres.Sixteen Casertana pigs (8 males, 8 females) from a farm in Campania (Italy) were slaughtered at one year of age. Muscle tissues were obtained from psoas minor, rhomboideus and longissimus dorsi. Myofibres were stained for myosin adenosine triphosphatase, succinic dehydrogenase, and α-amylase-periodic acid schiff. For all fibre types, the area and perimeter were measured. Slowtwitch oxidative fibres, fast-twitch glycolytic fibres and fast-twitch oxidative-glycolytic fibres were histochemically differentiated; an image-analyzing system was used. The results showed significant differences between the sexes in the size of all three fibre types. The psoas minor muscle had a high percentage of slow-twitch oxidative fibres and contained more capillaries per fibre and per mm 2 than rhomboideus and longissimus dorsi, in which fast-twitch glycolytic fibres dominated. The cross-sectional area of all fibre types was larger in longissimus dorsi than in rhomboideus and psoas minor muscles; the giant fibres were present in the longissimus dorsi muscle only. Besides, isometric tension values were higher in fast-twitch glycolytic fibres than in the other ones. Variations in fibre type composition may contribute to meat quality. Giant fibres, myosin adenosine triphosphatase, succinic dehydrogenase, capillaries, shortening velocity, isometric tensionThe Casertana breed is an autochthonous pig breed of ancient origin, now threatened with extinction. In the past it was considered a very fine breed, raised in the Campania region and the surrounding area in South Italy. It was valued for its productive performance particularly regarding the fattening tendency. It is characterized by slow growth and massive accumulation of backfat; its coat is bright black and hairless. The purpose of this study was to complete the knowledge regarding the Casertana pig in order to valorise this breed and to study its meat quality characteristics. Porcine meat quality can be affected by variation in muscle fibre type composition (Depreux 2000). Muscle fibre types may be classified based on enzymatic activity; in this study the following nomenclature was used for myofibre types: FG (fast-contracting with glycolytic metabolism), FOG (fast contracting with glycolytic-oxidative metabolism) and SO (slow-contracting with oxidative metabolism). The aim of this study was to evaluate the effect of sex on the histochemical and morphometric characteristics of muscle fibres on the basis of myosin adenosine triphosphatase (myosin ATPase), succinic dehydrogenase (SDH), to analyse the contractile properties of pig muscle fibres and to determine the presence of giant fibres in the muscles consi...

Histological and Histochemical Properties of M. Semitendinosus in German Landrace Pigs at Birth and Market Weight/Histološke I Histohemijske Osobine M. Semitendinosus-A Svinja Rase Nemački Landras Na Rođenju I Na Završetku Tova

“…In this research, in m. semitendinosus of slaughter pigs it were determined about 21 % of STO fi bers, 28 % of FTO fi bers and 52 % of FTG fi bers. The cross sectional area of different fi ber types in m. semitendinosus of slaughter pigs obtained in this study was 3800-4650 μm 2 , which is in accordance with results of [5] and [18].…”

Comparison of M.Semitendinosus Morphometry and Structure in Gilts and Barrows at Market Age

“…The analysis of histological structure of this muscle showed signifi cant differences due to gender. The average cross sectional area of muscle fi bers was larger in barrows than in gilts, but a statistically signifi cant difference (p<0.05) was determined only for FTO fi bers, which is in accordance with results of some authors [7][8][9], but contradictory to other authors [10][11][12]. An inverse relationship between the number and cross sectional area of muscle fi bers was obtained.…”

“…Some authors [5,6] point out that gender has no infl uence on the distribution of different muscle fi ber types. Other authors [7][8][9] consider gender as a factor affecting the diameter of muscle fi bers, with gilts having fi bers of a smaller diameter compared to barrows. On the contrary, there are data indicating a larger diameter and fi ber girth in gilts compared to barrows [10][11][12].…”

Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl1

“…Petersen et al (1998) and Velotto et al (2010) both reported capillary-to-fiber ratios that ranged from 0.90 to 1.50 for the psoas major, rhomboideus, and longissimus dorsi muscles. The current study found ratios that ranged from 1.44 to 2.21 for all locomotor muscles examined.…”