This study was carried on 80 native c ow calves in a large farm belonging to Cooperative Comittee forAnimal Producetion, Abu Hammad in Sharkia Province.These animals were classified, according to the clin- ical symptoms, into 4 groups, each of them contained20 calves as follow:- First groups:Were apparently clinically normal calves kept as control. Second group: Exhibited respiratory d.isorders. Third group: Represented by calves suffering from sporadic diarrhea.Fourth group:Were calves that exhibited skin lesion that proovedto be ringworm. Blood samples wer~ collected from clin-ically normal and diseased calveg to evaluate the level of serum GUT, S. GPT, LDH, alkaline and acid phosphata- bses, cholinesterase (in plasma & RBCs) , amylase and lipase; The study of the biochemical analysi$ showed the following points:-