Effects of Dietary Arsenical Inclusion on Lipid Metabolism and Liver Function in Mule Ducks

This study evaluated the effectiveness of different arsenical sources on inducing fatty liver, on changes in lipid metabolism and on liver function in mule ducks. Sixty twelve-week-old mule ducks were selected and randomly divided into five treatments, including the control group and four different arsenical sources; Roxarsone (300 mg/kg), arsanilic acid, $As_2O_5$ or $As_2O_3$, containing 85.2 mg/kg arsenic were included in the basal diet. The ducks were fed the medicated basal diet for 3 weeks followed by a one-week drug withdrawal. The results showed Roxarsone treatment decreased body weight, feed intake, liver weight and abdominal fat weight (p<0.05), while it increased the relative liver weight (p<0.05) during medication period ($3^{rd}$ week). The $As_2O_5$ treatment decreased abdominal fat weight and relative abdominal fat weight when compared to the control (p<0.05). Only Roxarsone among the treatment groups increased feed intake, liver weight and relative liver weight, while the $As_2O_3$ group showed the lightest liver weight and relative liver weight among treatment groups during the withdrawal period ($4^{th}$ week). The Roxarsone group decreased (p<0.05) NADP-malic dehydrogenase (MDH) and acetyl-CoA carboxylase (ACC) activities and increased (p<0.05) cholesterol concentration during the medication period, and elevated the MDH and ACC activities during the withdrawal period. All four arsenical treatment groups showed lymphocytic infiltration in liver tissue, while the Roxarsone and $As_2O_3$ treatments showed an increase in aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities (p<0.05). During the withdrawal period, arsenical treatments resulted in liver vacuoles. However, the arsenicals differed in effectiveness and mechanisms of inducing fat vacuoles.