Metabolic characteristics of the Gluteus medius muscle in crossbreed drafthorses

To evaluate anaerobic and aerobic metabolism of thr Gluteus medius muscle, biopsies of 16 clinically healthy draught horses of both sexes, were obtain ed at 3, 6 and 9 cm of depth. Creatinekinase (CK), lactic dehydrogenase (LD H) and citrate synthase (CS) activities in inactive and in working animals doing agricultural work was determined. The muscle tissue was homogenised, sonicated and centrifuged. Then the enzy matic activities were determined in the supernatant. The results obtained indicated that CK specific activity did not change acc ording to depth of sampling, LDH specific activity was lower at a depth of 9 cm in inactive equines and CS specific activity increased. All enzymatic activities increased significantly in working horses compared to inactive i ndividuals. The draught horses doing agricultural work increased their muscular metabol ism, principally their aerobic muscular metabolism, avoiding the glycogen s torage and muscle fatigue.