Department of Poultry Diseases, College of Veterinary Medicine, University of Zabol, Zabol, Iran
Round heart disease is a disease of unknown etiology in turkey. The objective of this study was to examine the effect of different amounts of sodium chloride in inducing cardiomyopathy in turkey poults. There are some reports that hypoxia and furazolidone can induce cardiomyopathy in turkey. Two hundred 2-day-old turkey poults were wing-banded and placed randomly into 6 groups and 24 replicates (4 replicates for each group). The 6 groups received commercial turkey starter diet contain 0.12, 0.17, 0.22, 0.27, 0.32 and 0.37% of sodium, respectively. They had access to food and water ad libitum. Suffering and dead birds were weighed and examined for post-mortem study. Live body weight of turkey poults measured individually on days 1, 2, 5 and 19. To study the hearts for presence of cardiomyopathy, on the day 19, all the poults were weighed and killed by cervical dislocation. The pieces of the hearts were placed into numbered tubes, flash frozen by liquid nitrogen and stored at -70ºC for myoglobin and hemoglobin microassay. The assay was based on spectrophotometry and separated myoglobin and hemoglobin by ammonium sulphate extraction. For determination of cardiomyopathy the ratio of the inner cavity of left ventricle to the total diameter of the left ventricle (IClv/TDlv) was calculated. Myopathic ratio for groups 1, 2, 3, 4, 5 and 6 were 0.1, 0.29, 0.3, 0.34, 0.35 and 0.36, respectively. Turkey poults which received excessive salts drank more water which produced volume overload, more cardial muscle activity, needed more oxygen and were more likely to develop myopathy. Cardiac muscle myoglobin and hemoglobin microassay showed that there was no significant relationship between the amount of myoglobin and hemoglobin with the amount of diet sodium.