Effect of neem leaves ( Azadirachta indica) on immunity of commercial broilers against new castle disease and infectious bursal disease

Most of the commercial poultry grower use antibiotics as growth promoters and to reduce the chance of occurrence of infectious diseases, which usually result in higher costs of production and ultimately lower net returns. Some plants and their extracts improve feed intake and their enzymatic activity may have antimicrobial, coccidiostatic or anthelmintic effects. Some researchers have investigated that neem when used in poultry feed; increases antibody titer against infectious bursal and Newcastle disease (ND). A total of 144 day old commercial broiler chicks were used in this study. The present study showed that mean antibody titer values against ND on day 42 in the groups A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, C4 were 2048, 1024, 512, 128, 2048, 1024, 512, 64, 2048, 1024, 1024, 64 respectively. The mean antibody titer against infectious bursal diseases (IBD) at day (42) in group A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3 and C4 was found to be 3413, 3368, 3181, 2813, 3552, 3334, 3190, 2884, 3611, 3458, 3319 and 2814 respectively. During this study it was concluded that addition of neem leaves in broiler feed has better effects on antibody production against new castle and infectious bursal disease viruses.   Key words: Newcastle disease, antibody titer, infectious bursal disease, neem leaves.