Department of Veterinary Parasitology, ¹ Department of Veterinary Microbiology, University of Agriculture, Faisalabad-38040, Pakistan

Abstract   

    Humoral immune response of Vaccine-I (superrnatant from sonicated sporulated oocyst), Vaccine-II (sediment from sonicated sporulated oocyst) and Vaccine-III (un-sonicated sporulated oocyst) against coccidiosis in chicken was determined by indirect haemagglutination (IHA) test. IHA antibody titre was significantly higher (P<0.05) in chicks vaccinated with Vaccine-I as compare to Vaccine-II and Vaccine-III. The IHA antibody titre of chicks vaccinated Witil Vaccine-I ranged from 1:8 to 1:8192, 1:16 1:512 for Vaccine II and 1:2 to 1:64 for Vaccine III. Vaccine I gave l00 per cent protection and oocysts appeared in the faeces (100-200 per gram) on day 10 post challenge which gradually increased (600-900 per gram) on day 16 and 200-400 on day 20 post challenge. Vaccine II gave 60 per cent protection and oocyst appeared in tile faeces (3.50,000-4,50.000 per gram) on day 8 post challenge which gradually increased (700,000-900,000 per gram) on day 16 and 100,000-200,000 on day 20 post challenge. Vaccine III gave 30 per cent protection and oocyst appeared in the faeces (8.50,000-9.00,000 per gram) on day 7 post challenge which gradually increased (11,400,000-12,00,000 per gram) on day 16 and 8,40,000-9,00,000 on day 20 post challenge. In control group, characteristic bloody diarrhoea was observed in all the clucks and oocysts appeared in the faeces (10,00,000-12,50,000 per gram) on day 5 post challenge of faeces which gradually increased (15,00,000-17,50,000 per ~) on day 16 post challenge. Results of the humoral and challenge response indicated tllat the Vaccine I induced a strong protection as immune chicks contained high level of antibodies that resisted heavy dose of challenge and gave 100 per cent protection.    

Key words: Immunity, Coccidiosis, Sonicated Vaccine.