Objective: To evaluate the eletrocardiographic changes in the experimentally induced ascites in broiler chicks using T3 model. Design: Comparective study.
Animals: A total of 150 one- day- old male cockerels from Ross breed.
Procedure: Chicks were randomly divided into two equal groups (control and test). Chicks were reared for six weeks. T3 (1.5 ppm) was added to the diet of the test group from the 6th day of rearing period to the end of 6th week. At the end of each week, 5 chicks from each group were selected and electrocardiographic recordings were performed.
Statistical analysis: Student's "t" test and Analysis of Variance.
Results: There were significant elevation of the amplitude of R

and S waves at the end of the 3 rd and 6 th weeks (for R waves), 2 nd

and 6th weeks (for S waves) in the test group in the leads III, a VF and a YR. The amplitude of both of these waves were elevated significantly in the test group, when they were considered as total means of weeks. There were significant elevations of the amplitude of R waves at the end of 6th compared with the other weeks in all 3 leads and the amplitude ofS waves at the end of 6th week compared with the 5th in the lead III. There were no significant changes in the direction of MEA.
Conclusion: Recorded electrocardiograms can be used effectively to evaluate the likelihood of development of ascites syndrome in broiler chickens. The increase in the amplitude of Rand S waves could be considered as the sign of ventricular hypertrophy. J. Pac.
Vet. Med. Univ. Tehran. 58, 4: 297-300, 2003.