Regulation of intracellular Ca<sup>2+</sup> concentration and meat quality in pigs

Abstract

The meat quality of pigs is essentially dependent on the rate and intensity of energy metabolism after slaughter. The major cellular processes in muscle cells are regulated by the Ca 2+ concentration in the cytoplasm, stimulating different energy consuming ATPases. The most essential regulator of the Ca 2+ concentration is the sarcoplasmic reticulum (SR) with its membranes, the SR Ca 2+ ATPase (Ca 2+ pump), and the calcium release channel (CRC). Defects of one or more of these elements will be of influence on the metabolism and ultimately on the meat quality. This is widely investigated in pigs with a mutated CRC. However, pigs without a mutation in the CRC also show a wide variability in their meat quality, dependent on other factors e.g. stress or season of the year. The variability in meat quality in these "normal" pigs is at least partly a result of differences in SR Ca 2+ transport and the resulting metabolism. IntroductionThe pig breeding systems aiming for an increase of the lean meat percentage have been very successful in the preceding decades. However, parallel with an increased meat content there was an increasing part of carcasses showing inferior meat quality and also an increase in losses by death during transportation or other kinds of stresses. A major reason for this relationship has been shown to be a mutated calcium release channel (CRC) of the sarcoplasmic reticulum (SR) (MCLENNAN and PHILLIPS, 1992). It turned out, that this mutation causes an insufficient regulation of the intracellular Ca 2+ concentration, activating metabolic processes not only in the live pig muscle, but also after slaughtering the animals. Currently all major pig producing

Meat quality and ultrastructure of muscle tissue from fatteners of Wild Boar, Pulawska and its crossbreed Pulawska × (Hamshire × Wild Boar)

“…The analysis of muscle tissue microstructure demonstrated that the studied genetic groups had a normal structure of muscle tissue and did not show any degenerative lesions. The muscles visualized a well preserved sarcomere structure, proper cell nuclei and mitochondria as well as regular cross striation giving evidence for the muscle decontraction state (KÜCHENMEISTER and KUHN 2003). A lack of degenerative changes was most likely to rise from a fact that glycolysis process proceeded properly and meat acidity increased gradually.…”

Effects of feeding canola meal from high-protein or conventional varieties of canola seeds on growth performance, carcass characteristics, and cutability of pigs

“…The potential for hypothyroidism to reduce calpain activity may result in decreased tenderness (Marple et al, 1975;Küchenmeister and Kuhn, 2003). However, lack of differences in shear force provided evidence that glucosinolates levels in the canola meal used in this experiment did not cause negative effects on tenderness.…”

Changes in selected physicochemical parameters of breast muscles of geese from Polish conservation flocks depending on duration of the post slaughter period

“…The increase in meatiness as well as rearing conditions, nutrition, handling and slaughter related processes could affect the chemical composition of muscles, their yield, as well as the mechanism which intervenes when muscles become meat (BERRI, 2000). It is well documented that stress (feed and water deprivation, struggling, stunning and environmental conditions, like hot temperature) affects the quality of the meat, and this effect depends on both duration and intensity of the stress period (OFFER, 1991;PINGEL and KNUST, 1993;LENGERKEN et al, 1997;KÜCHENMEISTER and KUHN, 2003). Some of the technological properties of meat can be determined by the rate of glycolysis, measured directly after animal slaughter (PINGEL and KNUST, 1993).…”