ABSTRACT
Modern strains of broiler are highly susceptible to heart failure. Heart related mortalities are observed predominantly in fast growing broiler chickens. The aim of this study was to investigate serotonin levels in ascitic and non ascitic broilers of three strains [Ross, Arbor Acres plus and Cobb]. In this respect, a factorial test in CRD method applied for the statistical analyses. In each of these three strains, 12 ascitic and 12 non-ascitic broilers were selected. After tagging and blood sampling, blood were collected and divided in two parts. One part was applied for some blood hematological assessment and other part was used for determining serum serotonin levels. The results showed significant differences among the strains [p<0.05]. The blood serotonin levels of ascitic chickens were significantly lower than the non ascitic ones [p<0.05]. There was a significant interaction between strain and disease in blood serotonin levels [p<0.05]