comparison of the susceptibility of six male broiler hybrids to ascites by using hematological and pathological parameters

this study was conducted to compare susceptibility of six different strains of male broilers to ascites syndrome. in this experiment, 612 one-day-old male broiler chicks from five international hybrids (e.g, arbor acres, cobb 500, hubbard, lohmann, and ross 508) and an iranian hybrid (arian) were used. growth performance, ascites mortality ratio, the ratio of right ventricle to total ventricles weight (rv:tv) in dead and healthy broilers, hematocrit values, serum levels of thyroid hormones (t3, t4) and t3: t4 ratio were studied to evaluate the susceptibility of the birds. the results showed that there were significant differences among the hybrids in ascites susceptibility. arian and hubbard were more susceptible, while, lohmann was more resistant to ascites than the other hybrids. the results of this study showed that rv:tv ratio and the hematocrit value can be sensitive indicators for differentiating hybrids susceptible to ascites from the resistant ones.