The present study was carried on 100 newly born buffalo calves of both sexes from birth up to 3 months of age to investigate the prevalence, etiology, haematological and biochemical changes, the antioxidant activity and histopathological changes related to enteritis and diarrhea. The prevalence of diarrhea was 60% and the mortality rate was 10%. Based on clinical examination and skin fold test calves were divided into three groups. The first group included 10 (selected from 40) apparently healthy calves that were used as a control group. The second group included 10 (selected from 38) calves suffering from mild diarrhea. The third group included 10 (selected from 22) calves suffering from severe diarrhea. The severity of diarrhea was assessed under field condition by the degree of deterioration in general systemic state such as dehydration and acidosis, skin elasticity, sunken eyeball, calf demeanor, body temperature, respiratory rate, and heart rate. The most common pathogens isolated from diseased calves were E.coli (73.3%) and Salmonella (26.7%). The hematological changes included increased in PCV% and WBCs count and decreased in RBCs, Hb, MCH, MCHC and blood pH. The biochemical changes include significant hypocalcemia, hypophosphatemia, hyponateremia, hypochloremia, hypomagnesumia and decrease in glucose, Cu, Zn, Fe. The SOD as indicator for the antioxidant activity was significantly reduced in both mild and severe diarrhea compared to control. A strong negative correlation was found between the degree of diarrhea and the levels of Cu, Zn and Fe, repectively. In addition, there were significant elevation in liver enzymes (ALT and AST( , ALP and kidney function test (BUN, creatinine). Histopathological changes of intestinal mucosa revealed thickening of the mucosa and wall and occasionally desquamation or atrophy of lining epithelium in intestine of mild and severe diarrheic buffalo calves. The mesenteric lymph node showed expansion of the medullary sinuses by increased numbers of inflammatory cells mainly large macrophages, lymphocytes along with fibrin. It was cocluded that diarrhea occurred with high prevalence (60%) in newly born buffalo calf and associated with haematological, biochemical and histopathological changes. The results also signify the relationship between the trace elements Cu, Zn and Fe deficiency and the degree of diarrhea. In addition, the reduction of SOD highlights the role of oxidant injury in induction of enteritis in newly born buffalo calves.
KEY WORDS: Buffalo calves, biochemical, E-Coli, Skin fold test, Haematological, Enteritis, Prevalence, SOD