Alteration in the activity of blood and milk leukocytes together with the serum enzyme profile during sub-clinical mastitis in cross-bred cows

Abstract

In vitro activity of blood and milk leukocytes together with serum enzyme profile during sub-clinical mastitis in crossbred cows were evaluated after collection of blood and milk samples from normal (10) and sub-clinical mastitic (10) cows. Blood total leukocyte counts (TLC) and differential leukocyte counts (DLC) were estimated by standard hematological procedure. Milk somatic cell counts (SCC) was performed microscopically. In vitro phagocytic activity of blood and milk neutrophils was performed by colorimetric nitro blue tetrazolium (NBT) assy and mitogen concanavalin A (con A) induced blood and milk lymphocyte blastogenic response was evaluated by colorimetric MTT (tetrazolium) assay. Serum total protein and alkaline phosphatase (ALP) were measured by the stand biochemical methods. The alanine amino transferase (ALT) and aspertate amino transferase (AST) activities in serum were estimated by commercially available kit. Milk SCC was significantly higher in sub-clinical mastitic cows. Phagocytic index of both blood and milk neutrophils was significantly lower in sub-clinical mastitic cows than normal animals. Con- A induced blood and milk lymphocyte blastogenic response was significantly lowered in sub-clinical mastitic cows than. Serum albumin, globulin ratio decreased significantly during sub-clinical mastitis. Serum AST and ALP level in sub-clinical mastitic cows was significantly higher. The study indicated decreased blood and milk leukocyte activity and higher AST and ALP during the sub-clinical mastitis which could be used as a diagnostic tool for sub-clinical mastitis.