Immune response of chicken to an experimental sonicated coccidia oocyst vaccine.

A total of 120 one-day old broiler chicks (ross breed) were used to evaluate the humoral immune response of vaccine-i (supernatent from sonicated sporulated oocyst), vaccine-il (sediment from sonicated sporulated oocysts) and vaccine-iii (un-sonicated sporulated oocyst) against coccidiosis in chicks was determined by indirect haemagglutination (iha) test. iha antibody titre was significantlyhigher (p<0.05) in chicks vaccinated with vaccine-i as compare to vaccine-il and vaccine-iii. the iha antibody titre of chicks vaccinated with vaccine-i ranged from 1:7 to 1:7012, i: 16 to 1:410 for vaccine iiand 1:2 to 1:64 for vaccine iii. vaccine i gave 100 percent protection and oocysts appeared in the faeces (100-200 oocysts per grams) on day 11 post challenge which gradually number of oocysts increased, 650to 900 oocysts per grams on day 17 and 200-400 on day 21 post challenge. vaccine-ii gave 62 percent protection and oocyst appeared in the faeces (300,000-400,000 oocysts) on day9 post challenge whichgradually increased (800,000-900,000 oocysts) on day 17 and 100,000-200,000 on day 21post challenge. vaccine iii gave 33 percent protection and oocyst appeared in the faeces (800,000-900,000) on day 8 post challenge which gradually increased (100,000-1,250,000 per grams) on day 17 and 840,000-900,000 on day 21 post challenge. in control group, characteristic bloody diarrhoea was observed in allthe chicks and oocysts appeared in the faeces (1,000,000-1,250,000 per grams) on day 6 post challenge of faeces which gradually increased (1,400,000-1,750,000 per grams) on day 17 post challenge. theoverall findings of this study indicate that the humoral and challenge response of the vaccine i indicated a strong protection as immune chicks contained high level of antibodies that resisted heavy dose ofchallenge and gave 100 percent protection.