Analysis of diet samples used in feeding private dairy cows in Desouk in Kafr El Sheikh Province showed that rations were contaminated with aflatoxin (75-150 p.p.b.) which was reflected on physiological blood parameters showing low level of red blood corpuscles (R.B.Cs.), Mean corpuscular haemoglobin concentration (MCHC) and high level of packed cell volume (P.C.V.), mean corpuscular volume (M.C.V.) and mean corpuscular haemoglobin (M.C.H.). In contaminated group, serum showed low level of total protein, iron, copper, magnesium, sodium and potassium, as well as, high level of asparate amino transferase (AST) and alkaline phosphatase live enzymes.