Evaluation of Kadaknath Chicken for Coccidial Resistance by Oocyst Count, Lesion Scoring and Oocyst Index in Eimeria Tenella Infection

The aim of present investigation was to study the virulence of coccidiosis in Kadaknath birds, experimentally infected with E. tenella by OPG count, oocyst index and caecal lesions scoring. Sixty one-day old unsexed Kadaknath birds were randomly divided into a control, T1 and T2 groups comprising twenty chicks under each group. At d 21 of age, birds of T1 and T2 groups were individually inoculated with 10,000 and 20,000 of sporulated oocysts of E. tenella and from the d 5 to 9 pi, faecal droppings were collected for counting OPG. Also at d 4, 7 and 14 after E. tenella infection, 2 chicks from each challenge groups were euthanized and caecal lesions and oocyst index were scored. The results indicated that in both T1 and T2 challenge group, there was an increasing trend of OPG upto d 7 pi and the peak level of OPG was found at d 7 pi. Mean OPG was significantly (P<0.05) higher in T2 at d 6, 7 and 8 pi than T1. Mean caecal lesion score, oocyst index and OPG count were found to be maximum on d 7 pi for T1 and T2 groups. Lesions score was non significant at 4, 7 and 14 pi. However, oocyst index was significant (P<0.05) at d 7 pi. No mortality was observed in any of the treatment groups. As Kadaknath birds shed less oocyst and had lower lesion scores and oocyst index, hence, it can be concluded that this breed is less susceptible to coccidial infection.