Abstract
The efficacy of avian Escherichia coli vaccine was studied in the prevention of colibacillosis in layer chicks by using intramuscular and subcutaneous routes. Sixty, one day old Layer chicks were divided into 3 groups (A, B and C) of 20 each. Chicks in each group were randomly divided into 2 replicates. On 15th day of age, chicks in group C (control-non-vaccinated) were injected with 0.9% saline through intramuscular (ten chicks) and subcutaneous routes (ten chicks). Whereas, chicks in group A and B were injected with Avian E.coli vaccine through intramuscular and subcutaneous routes, respectively. Ten birds in each group (A and B) were injected with 0.3ml and ten with 0.5ml of vaccine. Chicks were monitored for 21 days post vaccination and antibody titer through ELISA and AGP were noted. The results obtained through AGP and ELISA shows a marked difference between control and treated birds. Moreover, a high antibody titer was observed in the group which had received 0.5 ml of vaccine through subcutaneous route. Thus it was concluded that a dose of 0.5 ml per bird through subcutaneous elicits a high antibody titer that may provide protection against avian E. coli
