Genetics of Dilated Cardiomyopathy in the Turkey

Kwaku Gyenai, Jun Xu, and Ed Smith, Comparative Genomics Lab, department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24060

Dilated cardiomyopathy is reported to account for about 2% of mortality in turkeys. . In several studies, we investigated the effects of nutritional and genetic factors on the incidence and severity of toxin-induced dilated cardiomyopathy in the domestic turkey, Melagris gallopavo. In one study, the results of which will be presented here, we evaluated the effect of dietary vitamin E and selenium (Se) on oxidative stress (OS) and the incidence and severity of furazolidone (Fz)-induced dilated cardiomyopathy. Standard turkey diets were supplemented with different concentrations and combinations of vitamin E (0, 50 and 100 IU/kg) and selenium (0.0, 0.3 and 0.5 mg/kg). Malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), and plasma uric acid (PUA) were used as biomarkers for oxidative stress. At two wks of age, measurements of MDA for birds fed normal diet were not different from those fed diet with toxic levels of Fz. However, GPx was increased for birds fed diets supplemented with 0.5 mg/kg Se, combinations of 50 IU/kg vitamin E and 0.5 mg/kg Se, and 100 IU/kg vitamin E and 0.5 mg/kg Se. GPx was highest for birds fed Fz-containing diets and a combination of 100 IU/kg vitamin and 0.5 mg/kg Se. No differences were observed for poults (young turkeys) fed normal diets PUA; however, PUA was high for poults fed Fz-containing.  Among birds fed Fz-containing diets, reduced MDA levels were observed for birds fed diets with a combination 50 IU/kg vitamin E and 0.3 mg/kg Se, and 0.5 mg/kg Se, respectively. At two weeks of age, poults fed normal diets supplemented with 100 IU/kg and 0.5 mg/kg vitamin E and Se combined had the highest GSH. Among birds fed Fz-containing diets, GSH was highest for those fed a 100 IU/kg vitamin E. At four weeks of age, birds fed normal diets and combinations of 50 IU/kg vitamin E and 0.5 mg/kg Se, 100 IU/kg vitamin E had the lowest concentration of MDA but highest GPx and GSH.  Though results of the biomarkers were inconsistent from two to four wks of age, for turkeys fed diet containing different concentrations and combinations of dietary antioxidant, our current findings suggest a role for increased OS in the progression of DCM.