Abstract
Calf diarrhea is a major economic concern in bovine industry all over the world therefore this study was conducted on forty newly born bovine Friesian calves of both sex from different localities in El-Behira governorate, aged from 7-30 days with average live body weight (35±2.5) kgs. Ten of them were clinically healthy and enrolled as healthy control group where other thirty calves on admission, were suffering from diarrhoea, variable degrees of dehydration, fever, poor suckling reflex, general weakness, dullness and some were recumbent. Whole blood and serum samples were collected from both healthy control calves and diseased ones before and after treatment to evaluate haemato-biochemical alterations along with acute phase response. Hemogram of examined calves showed a significantly increased total RBCS count, Hb content and PCV (%), while no significant changes were recorded in the total values of MCV, MCH or MCHC in diarrheic calves compared to others. Moreover, leukogram of diarrheic calves showed significant leukocytosis with more prominent neutrophilia when compared with control or treated groups. There was a significant increase of serum enzymatic activities of AST and ALT with a higher values of total plasma proteins, albumin, globulins, total bilirubin, direct bilirubin, chloride, potassium, blood urea nitrogen and creatinine, while blood levels of sodium and glucose was significantly reduced in diarrheic calves as compared with either control or treated groups. Serum analysis of acute phase biomarkers revealed significantly increased levels of serum amyloid A (SAA), haptoglobin (Hp), ceruloplasmin (CP) and c-reactive protein (CRP) in the diseased group compared with healthy control and treated groups, while oxidant-antioxidant profile showed a significant increase in the levels of malondialdehyde while, serum activity of total antioxidant capacity demonstrated a significant decrease in diarrheic calves. Based on obtained results, undifferentiated calf diarrhea has a negative impact on haemato-biochemical biomarkers with strong expression of oxidative stress and acute phase reaction in diarrheic calves.

Key words: Calf diarrhea, Acute phase response, antioxidant status, MD, TAC and APPS