Immunocompetence traits and their association with layer production traits in CARI-Sonali commercial layer chicken

Present investigation was carried out to evaluate the immunocompetence (IC) traits in a random sample of 82 single-hatched CARI Sonali chicks, associations among IC traits and also to analyze the effect of levels of IC traits on layer economic traits. IC traits included in vivo antibody response to Sheep RBCs, serum lysozyme concentration and serum IgG level estimated by Hemeagglutination (HA) test, ‘Lysoplate assay’ and SRID, respectively. Data on IC traits were analyzed by least squares (LS) analysis of variance by taking sex as fixed effect in the model. Data on economic traits were analyzed for the effect of IC traits and level was taken as fixed effect. The LS means of HA titre, serum lysozyme and serum IgG concentrations were 6.001±0.441, 5.692±0.324 μg/ml and 5.167±0.413 μg/μl, respectively. Sex had no effect on any IC trait. Phenotypic (r_P) correlations among IC traits were low in magnitude. Hens with high/medium HA titre level or with low/medium level of serum lysozyme concentration demonstrated significantly more egg weight at 40 weeks and lower age at first egg, respectively. The findings suggested incorporation of HA tire and serum lysozyme levels as selection criteria in the selection programme so as to genetically improve economic traits as well as the general immunocompetence in chicken.