A Histological Study of Myoglobin in Developing Muscle of the Pig

Myoglobin was not clearly detectable in muscle of 1-day-old pigs by a histochemical method. Some myoglobin positive fibers began to appear at 1 week of age and by 3 weeks the myoglobin concentration was clearly higher in certain fibers which we call myoglobin positive fibers. These myoglobin positive fibers corresponded to typical red fibers of the 6-month-old animal.