"Studies were conducted to document the impact of sludge-fertilized corn on the food chain under controlled experimental conditions that eliminated any direct ingestion of sewage sludge. Specifically, the studies were to determine whether sludge-borne heavy metals that accumulate in corn are secreted into the milk of dairy goats or are accumulated in the organs and muscle of goats or market lambs consuming corn silage containing up to 5.26 mg cadmium (Cd)/kg. Dry matter intake, milk production, and feed efficiency of dairy goats were not reduced by feeding a high-Cd corn silage continuously for 3 years - approximately half of their productive lives. Likewise, feed efficiency and daily gains of market lambs were not reduced by consuming high-Cd silage. Cd and zinc (Zn) from corn silage were not secreted into the milk from lactating goats, even though some animals were receiving approximately 5 mg Cd and 100 mg Zn/day. In contrast, Cu concentrations were higher in milk from goats receiving the control feed. The Cd concentrations in livers of both goats and lambs were always lower in animals receiving the control feed. These levels increased as the amount of silage Cd increased. Accumulations of Cd in animal kidneys were 5 to 10 times greater than those observed in livers, but they followed the same general patterns. Cd concentrations in animal heart and muscle were low and not affected by treatment. Zn, the only other element found to accumulate in silage as a result of treatment, did not increase in animal liver. heart, and muscle, but it increased slightly in lamb kidney as a result of feeding Zn-enriched silage. The concentrations of 16 other elements in the various animal tissues were not consistently affected when the animals were fed sludge-fertilized corn silage."