Auswirkungen des Malignen Hyperthermie-Syndroms (MHS) auf Fleischqualität, Muskelfasereigenschaften und Stoffwechselkriterien des M. longissimus von Pietrain- Schweinen

Abstract. Title of the paper: Effects of the malignant hyperthermia Syndrome (MHS) on meat quality, muscle fibre characteristics and metabolic traits of the Longissimus muscle in Pietrain pigs
In Pietrain pigs with the genetic defect MHS (MHS group; n = 11) and without this defect (MHR group; n = 17) the Longissimus muscle was examined from the time of slaughter to 24 h post mortem to characterize endogenous changes in structural and functional parameters of the fibres and meat quality. At the time of slaughter the muscle in the MHS group was characterized by eniarged fibre diameters, a reduced number of capillaries and an increased occurrance of angular fibres and giant fibres. The fibre type composition in the MHS group tended to an increased proportion of glycolytic fibres and decreased proportion of oxidative fibres. The activities of four enzymes indicating the energy metabolism were not significantly different between the groups immediately after slaughter. However, at the time 45 min post mortem the activities of all enzymes were less in the MHS group as compared with the MHR group. The IMP/ATP quotient was the same in both groups directly after slaughter and was increased by 19.6 % in the MHS group 45 min post mortem indicating a deficit in supply of ATP for the metabolic processes of development from muscle to normal meat quality. Reduced values were measured in the sarcoplasmatic Ca²⁺ ATPase activity of the MHS group as compared with the MHR group. The changes in microstructure and metabolism of the muscle were related to an impairment of meat quality, which was characterized by a low pH value, lighter-coloured meat and a high drip-loss. The results underline the demand to eliminate those pigs with the MHS genetic defect from breeding Stocks and to involve further traits of muscle into the selection.