effect of extracts of thyme (thymus vulgaris) on electrocardiographic parameters in experimentally ascitic broilers

The object of this study was to evaluate the effect of extracts of thyme (thymus vulgaris) on electrocardiographic changes in broilers suffering from experimental ascites caused by cold stress. one hundred and twenty 1-day-old (ross 308) male broiler chicks were randomly divided into 3 groups and 4 replicates (10 birds per replicate). the 1st and 2nd groups were fed with the basal diet, and 3rd group was fed with basal diet and 1.00% extracts of thyme. temperature was gradually decreased in 2nd and 3rd groups to 30.00% of the standard program from 2nd week until the 6th week. at the end of 4, 5 and 6 weeks, four chicks from each group were randomly selected and necropsied after recording the electrocardiograms (ecgs). according to the ecgs analysis findings, heart rate in ascitic group (2nd) was lower than 1.00 % extracts of thyme + ascitic group (3rd) and control group. in ascitic group, four cases of arrhythmias (sinus bradycardia) and one case of atrioventricular block were observed. the mean ecg intervals and amplitudes of waves in ascitic broilers were significantly longer than those of the control group. the amplitudes of t and s waves in the 5th and 6th weeks in the 3rd group decreased compared to the 2nd group. the present study showed that the addition of 1.00 % extracts of thyme to broilers diet improved ecg parameters; so, 1.00 % extracts of thyme can be effective in preventing ascites syndrome due to cold condition.