The heavy metal elements polluting animal-derived feed products mainly include lead, arsenic, cadmium, chromium and mercury. Bone meal and meat and bone meal may often contain a large amount of lead, arsenic, cadmium and other elements; feather meal and leather protein meal may contain a large amount of lead and arsenic, in addition, leather protein meal often contains a high amount of chromium; fish meal and other aquatic products In addition to a large amount of lead, arsenic, cadmium and chromium, the organism may also contain a large amount of mercury.

1 Fluorine

Bone meal, meat and bone meal and other animal-derived feed products may contain a large amount of fluorine to varying degrees due to different origins and raw materials. Animals raised in natural fluorine-rich areas and industrial fluorine-contaminated areas can accumulate a large amount of fluorine in their bones. Products made from such animal raw materials must contain high fluorine content. Long-term and large-scale use of such products can cause chronic chronic diseases in livestock and poultry. Fluorosis.

2 nitrite

According to foreign reports, sodium nitrite has been used as a preservative in the production of fishmeal. If the amount is too large, it can lead to nitrous acid poisoning in feeding animals, which may be transformed into dimethylnitrosamine, a carcinogen. Ji Zhenyang (2005), He Jin (2006) and other relevant experts reported that when toxic elements exceed the standard, there are the following toxic manifestations.

3 Chrome

① Combines with nucleic acid and nucleoprotein in animals, affecting the phosphorus content in tissues; ② Reduces the activity of amylase and prevents cysteinase oxidation; ③ Impairs the function of red blood cells to carry oxygen, causing lung cancer, especially lysis Chromium compounds, which are acid insoluble in water, are more dangerous.