Effect of Silybum marianum extract on electrocardiographic parameters in pekin ducks with lead nitrate poisoning

Lead is the second most dangerous heavy metal, which is widely spread in the environment due to the high use of this metal in industry, and through poisoning of water and food, it can poison humans and animals. The aim of this study was to investigate the effect of Silybum marianum seed extract on electrocardiogram parameters in lead poisoned ducks. 90 pekin ducks were divided into 3 groups including healthy control group, poisoned control group (40 mg/kg lead nitrate in the diet) and poisoned treatment group (40 mg/kg lead nitrate and 300 mg/kg of plant extract in the diet). In order to measure the height of T, S and R waves and the distances of ST, RR, QT and QRS and the electrical axis of the heart at the ages of 28 and 60 days, an electrocardiogram was prepared from 8 ducks in each group. The results showed that changes in R, S and T waves were observed in the poisoned control group and the height of these waves increased compared to the healthy control group, which is the result of lead-induced hypertension. The plant extract in the treatment group prevented the abnormal increase of these waves and the decrease of height in R wave in derivation III and also T wave in derivation III and aVF at 60 days were significant, statistically. Also, QRS and QT intervals increased in the poisoned control group and the plant extract significantly prevented the increase in QRS interval of derivation II at 60 days, QT interval in derivation III at 28 days and in aVF derivation at 60 days. Therefore, the seed extract improved cardiac electrocardiogram indices in lead-poisoned ducks.