Risk of Heavy Metals from Using Broiler Litter as an Alternative Animal Feedstuff or Organic Fertilizer

摘要

Potential risk of heavy metal residues in poultry litter is considered as one of the environmental concerns of litter applications on agricultural land or as animal feedstuff. Therefore, a total of 136 litter samples were collected from broiler farms and examined for the presence of cadmium (Cd), lead (Pb), aluminum (Al) and nickel (Ni) using ZEEnit 700P Atomic Absorption Spectrophotometer with Graphite Furness. The results showed that all litter samples contained notable concentrations of the analyzed metals and their order was Ni > Al > Pb > Cd. Standard limit for heavy metals in litter differs greatly if it is applied to pasture or as feed for animals. It was found that Pb content in litter was 8-10 times as FAO limit when used as fish feed. Meanwhile, Pb level was higher than the European Communities standard in 24% of litter samples when used as complete feedstuff for animals. However, Pb level was much lower than the Spanish legislation for fertilizers. Additionally, Al, Ni and Cd content did not exceed the legally permitted guideline limits when used as feedstuff or fertilizer. It was concluded that, poultry litter contained high Pb level, which may accumulate in the body and can pose health risk when used as an alternative feedstuff for fish and animals.