Avtor/Urednik		Lefaucheur, L
Naslov		Myofiber typing and pig meat production
Prevedeni naslov		Tipizacija skeletnih mišičnih vlaken in njen pomen v proizvodnji prašičjega mesa
Tip		članek
Vir		Slov Vet Res
Vol. in št.		Letnik 38, št. 1
Leto izdaje		2001
Obseg		str. 5-33
Jezik		eng
Abstrakt		Muscle fiber characteristics have long been thought to be important factors influencing meat quality; however, identifying a superior fiber type for meat production remains a tough issue. This could be due to the fact that myofiber type composition, as well as meat quality, are influenced by many genetic and environmental factors that are not sufficiently controlled in the experiments. After a brief presentation of recent knowledge underlying conventional fiber typing, this review describes myofiber type differentiation, and presents some factors of variation. Finally, current knowledge about the significance of myofiber typing in modulating growth performance and meat quality is discussed. This review covers data showing that muscle fiber type composition is highly variable and can be influenced by factors such as muscle type, breed, major genes, individual, sex, fetal and postnatal nutrition, ambient temperature, exercise, growth-promoting agents, and transgenesis. The heritability of some histochemical characteristics suggests that conventional selection on myofiber attributes can be efficiently used to manipulate muscle fiber type composition. The correlated responses of growth and meat quality traits to this kind of selection could bring valuable information to better understand the significance of muscle fiber type in determining growth performance and meat quality. Because of the intense changes occuring during the early postnatal period, altering muscle fiber type composition by nutritional and/or environmental factors at this time could be maximal. Finally, increasing the total number of fibers, a characteristic definitely established before birth in the pig, is a promising way to increase muscle mass without increasing fiber size which is sometimes speculated to alter meat quality.
Izvleček		Vpliv skeletnih mišičnih vlaken na kakovost mesa je razmeroma dobro poznan, vendar pa predstavlja identifikacija tipa mišičnih vlaken, ki je za proizvodnjo prašičjega mesa najpomembnejši dejavnik, še vedno nerešen problem. Na histokemično zgradbo mišic in kakovost mesa prašičev namreč vpliva več genetskih in drugih dejavnikov, na katere eksperimentalno ne moremo vplivati. V prispevku je naveden pregled novejših metod tipizacije mišičnih vlaken, razvojne preobrazbe vlaken in dejavnikov, ki nanjo vplivajo. Razpravlja se o pomembnosti tipizacije mišičnih vlaken v procesu oblikovanja prirastka in kakovost mesa. Rezultati raziskav kažejo, da je histokemični profil mišic zelo spremenljiv. Nanj vplivajo pasma živali, pomembnejši geni, spol, individualne razlike med živalmi, prehrana v času preporodnega in porojstvenega razvoja, temperatura okolja, telesna aktivnost, dejavniki spodbujanja rasti (growth-promoting agents) in spreminjanje genoma. Na histokemični profil mišic v veliki meri vpliva tudi selekcija živali na določene lastnosti, kar potrjuje soodvisnost med stopnjo prirastka in kakovostjo mesa kot posledica takšne odbire. Spremembe v skeletnih mišicah so najitenzivnejše v zgodnjem postnatalnem obdobju. V tem obdobju najlaže izzovemo spremembe v histokemičnem profilu mišic s spremenjenim režimom prehrane in drugih dejavnikov okolja. Povečanje skupnega števila mišičnih vlaken predstavlja obetaven način povečanja mišične mase živali, ne da bi se pri tem povečala debelina mišičnih vlaken, ki je pomemben dejavnik spremenjene kakovosti mesa.
Deskriptorji		MUSCLE, SKELETAL MUSCLE FIBERS, FAST-TWITCH MUSCLE FIBERS, SLOW-TWITCH SWINE MEAT HISTOCYTOCHEMISTRY BODY WEIGHT QUALITY CONTROL