Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
The present study was designed to examine the anatomical parameters of the cardiopulmonary system, the function of venous blood gas parameters and the development of ascites incidence in two genetic line chickens. Three hundred forty day-old chickens from two pure broiler breeder lines, which were different in their growth rate and susceptibility to ascites syndrome were obtained. The relative heart and lung weights, the volumes of the heart, lung and thorax cavity, the incidence of ascites, and the venous blood gas parameters in these two genetic line chickens were followed. In the present study, the incidence of ascites and right ventricular hypertrophy was markedly higher in the fast-growing broiler chickens compared to the slow-growing chickens, as two genetic line chickens exhibited significant differences in their growth performance traits. The volumes of the thorax cavity, before and after removing the heart and lung tissues, were lower in fast-growing broiler chickens compared to the slow-growing chickens. The relative lung volume was significantly lower in the fast growth chickens than the slow growth chickens at the earlier age, but it did not differ at the later age. Additionally, a rise in carbon dioxide tension and a decline in oxygen pressure in the venous blood of rapid growth compared tothe slow growth broiler chickens were observed. It could be concluded that there is an association between the insufficiencies of the cardiopulmonary system with the function of the venous blood gas parameters and the development of ascites syndrome in fast growing broiler chickens.