EFFECT OF GROWTH AND PLANE OF NUTRITION ON APPARENT MUSCLE-FIBER NUMBERS IN PIG

  • 1 January 1976
    • journal article
    • research article
    • Vol. 40  (3) , 285-292
Abstract
A histological sampling technique in the pig was used to estimate the number of muscle fibers appearing the transverse sections taken at the midlength of whole sartorius muscles growing at a rate of approximately 0.7 kg/day. Between 56-168 days (postnatal), the apparent number of muscle fibers increased at an approximate rate of 300 fibers/day. No evidence of the formation of new muscle fibers by myoblast fusion or muscle fiber fission was detected by light microscopy. Animals placed on a maintenance diet which prevented growth for 28 day periods prior to slaughter showed a fixation or decrease in apparent numbers of muscle fibers. The arrangement of muscle fibers during growth of the porcine sartorius muscle appears to be a dynamic rather than a fixed system.