Effects of diet and soil on the toxicity of lead in mallards

Captive game-farm mallards (Anas platyrhynchos) were dosed with five No. 4 lead (Pb) shot and placed on a diet of shelled corn or commercial duck food (6 ducks). Half of the ducks on each diet was dosed daily with 10 g of soil. The commercial duck food provided more protection from the effects of Pb toxicity than the 10 g of soil dosed daily. Ducks on corn only died a mean of 7 days after dosing, ducks receiving commercial duck food, with and without soil, survived to the end of the study (21 days after dosing), and ducks receiving a diet of corn and soil survived an average of 17 days. Although ducks receiving corn only dissolved less Pb, excreted less Pb in their feces, and retained less dissolved Pb than the ducks receiving the other three treatments, they retained more dissolved Pb per day than the other ducks.