Department of Veterinary Parasitology, CCS Haryana Agricultural University, Hisar-125004, India.
*Corresponding Author.
1A part of M.V.Sc. thesis of first author.
Four Eimeria tenella field isolates from Karnal (3 isolates) and Jind (1 isolate) districts of Haryana (North India) were studied in a battery test for evaluating their comparative pathogenicity. Broiler birds (Ross Strain) were infected with 105 sporulated oocysts each at the end of third week. The comparative pathogenicity of different isolates was assessed by calculating hematological values, oocyst index, lesion score and mortality. Haematological studies included estimation of haemoglobin, packed cell volume and total erythrocyte count. All the field isolates of E. tenella produced varying degree of pathogenicity. Infection with Karnal isolate - III and I resulted in maximum fall in all the parameters studied and Karnal isolate - III was found to be the most pathogenic as mortality was also recorded in this group. The degree of pathogenicity in Karnal isolate-II and Jind isolate was more or less the same.
