10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 3 2013 (July - September) Laying hen when immunized with antigens of lessThan i greaterThan Staphylococcus aureus lessThan /i greaterThan and lessThan i greaterThan Escherichia coli lessThan /i greaterThan , major etiological agent causing mastitis in dairy industries releases antibodies (IgY) which was purified and dialyzed. The concentration of antibodies increased steadily and reached a high titre by the 49 lessThan sup greaterThan th lessThan /sup greaterThan day of Immunization. The antibody titre was assayed by ELISA with a high OD lessThan sub greaterThan 490 lessThan /sub greaterThan value even at 1/10000 dilution. The protein estimation was done for antibodies by Lowry's method and was found to be 3.67 mg/ml for lessThan i greaterThan E.coli lessThan /i greaterThan and 3.94 mg/ml for lessThan i greaterThan S.aureus. lessThan /i greaterThan Protein profile of IgY antibodies analyzed by SDS- PAGE showed a band with molecular weight of 180 KDa. Growth inhibition assay when performed with 2.5mg/ml of specific IgY against the bacterial antigens showed reduction in growth of lessThan i greaterThan E.coli lessThan /i greaterThan and lessThan i greaterThan Staphylococcus aureus lessThan /i greaterThan . These results indicate that antibodies generated in chicken can be used for diagnosis and therapeutic purposes in bovine mastitis. R.MAHENTHIRAN , S.NAVEEN, T.DIRAVIYAM, K. RAVI KUMAR AND A.MICHAEL Mastitis, IgY, Staphylococcus aureus and Escherichia coli 687-696