The study included collection of 200 serum samples from Broilers which showed clinical signs of Respiratory and Digestive lnfections as well as noticable mortality. Samples were collected through two stages, first at acute infection and the second two weeks post infection from the same Broilers flocks.
ELISA test was used for the detection of Avian Influenza antibodies showed positive reaction for 50% of first stage serum samples and 78% Positive reaction of second stage serum samples.
Haemagglutination inhibition (HI) test also used for detection of antibodies using reference antigen to Avian Influenza virus subtype (H9N2). Results showed positive reaction of 42% of first stage serum samples with mean of titer at 24.19 and 52% positive reaction of second stage serum samples with mean of titer at 30.15. These results indicated the presence of antibodies against Avian Influenza virus subtype (H9N2). In broiler's flocks of Ninevah province and ELISA test was more sensitive than (HI) test in antibodies detection.