Evaluation of lipopolysaccharide and formaldehyde inactive escherichia coli vaccines in broilers

الملخص EN

This study was conducted to evaluate the lipopolysaccharide (LPS) and formaldehyde inactive E.

coli vaccine in different doses by determination the immune response of E.

coli and estimate the pathological changes post challenge with Escherichia coli.

Three hundred and fifty broiler chicks were used from one day to forty five day old, divided randomly into 7 groups, experimental groups treated by receiving LPS vaccine of E.

coli in different doses.

And other groups received killed vaccine of E.

coli through subcutaneous injection in different doses.

G3 that received LPS vaccine at dose (0.5 ml from 3×107 CFU/ml) given significant increase at level (P<0.05) in protection after challenge with E.

coli compared with other groups.

The LPS vaccine from local isolate gave better (cellular and humoral) immunity than the formaldehyde inactivated vaccine in vaccinated chicks after challenge with APEC