Bovine muscle glycogen as affected by fasting and refeeding

Twelve bulls about 12 mo of age were used to study the effects of dietary stress and realimentation on muscle glycogen depletion and repletion over time. Needle biopsy techniques were used to obtain longissimus muscle samples 11 d before fasting, at the end of fasting, and 3, 7, 10 and 14 d postfasting. Fasting reduced (P less than .05) muscle glycogen from 77 to 50 mumol glycogen-glucose/g. Depressed muscle glycogen content persisted through d 3 while animals were reestablishing normal feed consumption. A glycogen repletion rate of 3 mumol glycogen-glucose X g-1 X d-1 was observed from d 3 to 7.