AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.ijaronline.in *Corresponding author’s e-mail: prajwalitapathak@gmail.com Indian J. Anim. Res., 52(8) 2018: 1218-1222 Print ISSN:0367-6722 / Online ISSN:0976-0555 Evaluation and comparison of immune responsiveness to sheep red blood cells, PHA-P and IBDV vaccine in divergent stocks of chicken Prajwalita Pathak*, P.P. Dubey, S.K. Dash, D. Deka* and Varinder Raina Department of Animal Genetics and Breeding, Directorate of Livestock Farms, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana-141 004, Punjab, India. Received: 24-11-2016 Accepted: 17-02-2017 DOI: 10.18805/ijar.v0iOF.8457 ABSTRACT A total of 90 birds comprising two native breeds viz. Aseel and Kadaknath and one synthetic broiler stock i.e. IBL-80 were utilized to evaluate and compare antibody response to Sheep Red Blood Cells by haemagglutination test at 0, 5 and 10 days post primary inoculation, to study in vivo cell mediated immune response to mitogen Phytohaemagglutinin (PHA-P) and to evaluate immune responsiveness to IBDV vaccine. The presence of natural antibodies against SRBC was evident in all the genetic groups. All groups showed an increase in HA titre upto 10 days post immunization. The HA titre on 10 day was significantly higher in Aseel (1.88±0.10) followed by IBL-80 (1.13±0.05) and Kadaknath (1.09±0.06). However, the differences among Kadaknath and IBL-80 at day 10 PPI were failed to attain statistical significance. The in vivo cell mediated response to mitogen was highest in Aseel (0.68 mm) followed by IBL-80 (0.59 mm) and Kadaknath (0.43 mm).There was significant difference between the layer breeds for response to phytoheamagglutinin but IBL-80 was not significantly differ from both Aseel and Kadaknath. The titre values for IBDV were lowest before immunization and got increased during 7, 14, 21 DPI. At 14 DPI the titre value were significantly different in all the breeds in which Aseel exhibited the highest titre value (2.96±0.04) followed by IBL-80 (2.77±0.09) and Kadaknath (2.64±0.06). It was found that at 21 DPI antibody response was highest in all the breeds, however differences in titre value at 21 DPI in different breeds were not significantly different. Key words: Aseel, Immune responsiveness, Kadaknath, Phytohaemagglutinin, Sheep Red Blood Cell. INTRODUCTION Poultry industry is one of the fastest growing segments of agricultural sector today in the world as well as in India. Disease resistance is an important trait of chicken that directly ascertain the economic returns from the poultry production. Over the years there has been much emphasis on growth improvement that is negatively associated with some aspects of immunological performance of poultry as reported by Hans and Smyth (1972), Qureshi and Havenstein (1994), Rao et al. (1999), Yunis et al. (2000), Cheema et al. (2003). Infectious diseases are responsible for major economic losses in poultry production. Although vaccines and medications are widely used for prevention of losses due to diseases, but they pose an economic burden and their use is to be reduced due to ethical reasons like residue in animal products etc. Genetic resistance to the diseases is inherited and can enhance the response to vaccine (Gavora and Spancer, 1979, Gavora et al. , 1990). Resistance to disease can be specific or general. Specific resistance to particular disease protects the birds against single pathogen. A wide range of pathogens has been studied for development of resistance. The general disease resistance refers to the enhancement of immune potential of birds so that they can survive many type of pathogens. Genetic enhancement of immune competence without challenging birds with disease agents may be a potential approach for improving health and production parameters as well as disease resistance. Indirect selection for immune response traits can improve genetic resistance to disease (Vanderzipp, 1983). Development of stocks resistant to wide variety of diseases i.e. general disease resistance, provide a good expectation of reducing the expenditure on preventive and vaccination programmes. Incorporation of genetic resistance has several advantages including the enhancement of the immune response to vaccines (Gavora and Spencer, 1979). Immune responsiveness in poultry can be evaluated by challenging the birds with antigens. These antigens may be causative agents of disease like Marek disease virus, New castle disease virus, but they are expensive, time consuming and will cause morbidity and mortality in flock since they are pathogenic nature. So the appropriate way to study immune-competence in a species is to challenge it with non- pathogenic, non-specific antigen like Sheep Red Blood Cell (SRBC), mollusk Haemocyanin, Chicken Egg White Lysosome and Bacterial Lipopolysaccharids or to measure