The Effect of Various Levels of Exercise in Altering the Chemical and Physical Characteristics of Certain Pork Ham Muscles

Abstract

Market weight hogs from two experiments were given various levels of forced exercise through the use of a control animal exerciser. The effects of this type of stress on the ham muscle classification and certain chemical and physical characteristics of the gluteus medius muscle at slaughter and subsequent to a 24 hr. chill were studied. When repeated exercise was given, the hogs seemingly adjusted themselves rapidly to this type of treatment. The hams from these hogs were very similar to the controls in appearance and characteristics. Fasted and full-fed hogs that were subjected to single, severe exercise possessed muscles that were dark in color, high in pH value and dry in appearance. The exercise treatment on both fasted and full-fed animals significantly decreased initial muscle glycogen. As the muscle glycogen was decreased, the pH value was raised and the muscles appeared dark in color. The increase in the intensity of the muscle color of the severely exercised lots was not solely a reflection of increased pigment quantities. It is postulated, however, that this increase in color intensity was due to a change in muscle consistency as a result of its higher pH. Copyright © . .