Table 2.
Metal and metalloids of importance to poultry. Possible adverse effects and toxicological guidance limits for dietary ingestion in chickens.
| Compound | Source | Clinical signs of toxicoses in poultry and humans | Recommended maximum level in total diet (mg/kg DM)1 | EU feed maximum levels (mg/kg, 12% feed moisture)2 | Maximum levels (mg/kg) in poultry meat (and liver) | Toxicological guidance values |
|---|---|---|---|---|---|---|
| Arsenic | Drinking water, pesticides, coccidiostatics, wood-preservatives | Vaso-oclusion, peripheral neuropathy, encephalopathy, compromises immune system, carcinogenic | 0.2 (cattle, sheep, pigs)2 | 2 (EU, 2015) | 0.02 (1.0) (FSANZ, 2001) | Reduced weight gain after 10 × daily doses of 100 mg hydroxydimethylarsine oxide/kg BW but no clinical signs after exposure to other arsenic compounds up to a daily dose of 250 mg/kg BW (EFSA, 2005a) |
| Cadmium | Battery pigments, natural emissions | Oxidative stress, nephrotoxic, hepatotoxic, reduced growth | 1 | 0.5 (EU, 2013) | 0.05 (1.25) (FSANZ, 2016a, FSANZ, 2016b) | Diets with 12 and 48 ppm resulted in increases in the cadmium content of liver and muscle (EFSA, 2004b) |
| Copper | Wood preservatives, disinfectants, pesticides | Essential trace element, excess cooper induces oxidative stress resulting in kidney, liver, and gastrointestinal damage | 200 | Na | 2 (50) (FSANZ, 2001) | Dietary cooper above 250 ppm may increase feed conversion rate, and cause severe oral and gastrointestinal erosions (EFSA, 2016) |
| Lead | Natural emissions, battery manufacturing, paints | Neurotoxicity, cardiovascular adverse effects, nephrotoxicity | 5 (cattle, pig, sheep)2 | 5 (EU, 2017) | 0.1 (0.5) (FSANZ, 2016a, FSANZ, 2016b) | LOAEL of 1 ppm (EFSA, 2004c) |
| Mercury | Natural emissions, batteries, preservatives | Neurotoxicity, adverse renal, and pulmonary dysfunction | 0.01 (cattle, pig, sheep)2 | 0.1 (EU, 2017) | 0.01 (0.01) (FSANZ, 2001) | NOAEL 2.2 mg/kg feed for young chickens (EFSA, 2008a) |
Abbreviation: LOAEL, lowest observed adverse effect level; NOAEL, no observed adverse effect level.
1
Maximum recommended values for feedstuff in Australia as revised by MacLachlan et al. (2013). When there were no values recommended for chickens, species for which recommendation is given in parenthesis.
2
na = not available.