The activity of muscular-specific enzymes (S-GOT, S-GPT, S-LDH, S-CPK) were found to be normal in 55 of 85 newly borne lambs (7-10 days old) in a flock with nutritional muscular dystrophy. The recorded values were 30.2+5.04, 9.1+4.05, 613.0+61.0 and 23.1+2.0 mu/ml respectively.
Activities of these enzymes were very high in remaining animals (35.3% of flock). The value reached : for S-GOT 278.7+13.1, S-GPT 84.8+6.7, S-LDH 1261.8+33.2 and S-CPK 995.5+1.04 mu/ml. A prophylac tic intramuscular dosage of 1 mg selenium and 300 mg tocopherol acetate (one dose) had the effect that within one week the increased enyme activity had returned to the normal values. Non of treated lambs had muscular dystrophy later.