Determination of the Toxic Level of Dietary Mercury and Prediction of Mercury Intake and Tissue Mercury Concentrations in Broiler Chickens Using Feather Mercury Concentrations

The current experiment was conducted to determine the toxic level of dietary mercury (Hg) and to predict Hg intake and tissue Hg concentrations in broiler chickens from feather Hg concentrations. A total of 800 3-d-old broiler chickens (400 male and 400 female birds) were allotted to one of 80 battery cages in 2 x 5 factorial arrangements of sex and 5 concentrations of Hg in diets with 0, 50, 100, 250, or 500 mg/kg. The mercury chloride was used to increase Hg concentrations in diets. Experiment lasted for 32 d. There were no interactions between sex and dietary treatments for all measurements. A greater than 250 mg/kg Hg had negative effects on broiler performance. The one-slope broken-line analysis with dietary Hg concentrations and BW gain revealed that a greater than 209 mg/kg Hg in diets was toxic to broiler chickens. Feather Hg concentrations were greater than liver and breast Hg concentrations across all treatments, indicating that the feather is the most responsive tissue to dietary Hg concentrations. Accordingly, the equations for predicting daily Hg intake and Hg concentrations in the liver and breast were generated from Hg concentrations in the feather. Resulting equations indicated that feather Hg concentrations are good predictors of both Hg intake and Hg concentrations in the liver and breast. In conclusion, the toxic level of Hg is near to 200 mg/kg in broiler diets. The Hg intake and Hg concentrations in the liver and breast can be precisely predicted from Hg concentrations in the feather.