Dietary manipulation of pro- and macroglycogen in porcine skeletal muscle

• Published in: Journal of animal science 2003-01, Vol.81 (1), p.130-134
• Main Authors: Rosenvold, K, Essen-Gustavsson, B, Andersen, H. J
• Format: Article
• Language: English
• Subjects: Animal Feed; Animal Nutritional Physiological Phenomena; Animal productions; Animals; Biological and medical sciences; Diet; Dietary Carbohydrates - administration & dosage; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Glycogen - chemistry; Glycogen - metabolism; Glycolysis - drug effects; Hogs; Meat - standards; Muscle, Skeletal - chemistry; Muscle, Skeletal - metabolism; Muscular system; Postmortem Changes; Random Allocation; Skeletal system; Swine - metabolism; Terrestrial animal productions; Vertebrates; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/2003.811130x

The aim of the study was to investigate how feeding-induced changes in muscle glycogen stores affect the ratio of between the glycogen pools, pro- and macroglycogen. Pro- and macroglycogen content were determined in longissumus muscle from slaughter pigs subjected to a feeding strategy known to reduce total glycogen stores. Furthermore, early postslaughter glycolysis of the two glycogen forms was determined. The feeding strategy involved a diet (GLYRED diet) with a low digestible carbohydrate (5%)/high fat (18%) content, which was fed to the pigs the last 3 wk before harvest. A control group was fed a standard pig diet (49% digestible carbohydrate/5% fat). Total glycogen was reduced by 48 micromol/g dry weight (d.w.) in GLYRED pigs during the 3-wk feeding period. This was mainly due to a reduction in macroglycogen of 42 micromol/g d.w. During postmortem glycolysis the proglycogen appeared to be degraded in favor of macroglycogen. Moreover, total glycogen was degraded to a larger extent in muscle from the control pigs compared with muscle from GLYRED pigs. This difference was due to a significantly greater degradation of proglycogen in the control pigs. In conclusion, the results support earlier studies suggesting that proglycogen and macroglycogen are different glycogen pools that have different functions. Furthermore, the results show that the muscle glycogen pools can be manipulated through diet and that proglycogen is degraded in favor of macroglycogen under the anaerobic conditions postmortem.