Production of dark firm dry meat in slaughtered pigs with so-called liver degeneration characterized by yellowish discoloration and high lipid contents.

The livers which are discolored yellowish and have a large amount of lipids (liver degeneration) are frequently observed in slaughtered pigs. Dark firm dry (DFD) meat and liver degeneration have a common etiological agent of exhaustion in pigs before slaughter. The correlation between them was examined. In 65 cases of 77 slaughtered pigs with the degenerative liver, which contained more than 6.6% total lipids of liver wet weight, the carcasses showed early rigor mortis and the higher final pH above 6.0. R values of the muscles, which indicated the decrease of ATP, were higher. The meat had a DFD appearance and the muscle fibers had no tendency to shrink. These data showed that the pigs with liver degeneration produced DFD meat at a high rate. In 4 cases of 5 pigs exhausted experimentally by 53 hr fasting and hard exercise before slaughter, both liver degeneration and DFD meat were produced simultaneously. The livers of them were discolored and contained about 8.0% or more total lipids. The carcasses of them showed early rigor mortis and the higher final pH above 6.0. From these data, it was suggested that the exhaustion in pigs before slaughter caused both liver degeneration and DFD meat.