In animal husbandry and aquaculture feed quality is good or bad is the majority of farming households are very concerned about the problem, especially after the large-scale use of feed additives, many new problems are gradually exposed, heavy metal poisoning is one of them.

Heavy metal is implicit in the feed additive, the additive is predominantly montmorillonite, raw materials for the production of montmorillonite is a result of natural bentonite, and natural bentonite containing a variety of heavy metals.

If these heavy metals in the production process are not handled properly, will lead to heavy metal content of montmorillonite feed exceeded, if long-term edible excessive heavy metal content in the feed will be poisoning, common heavy metal poisoning and performance are as follows:

Fluorosis, bone meal, meat and bone meal and other animal feed products because of different origin and raw materials, different degree to contain large amounts of fluoride. In natural rich fluorine area and the area of fluorine pollution reared animals, bones can accumulate large amounts of fluorine, this kind of animal raw material products inevitable fluoride high, long-term, extensive use of this product can cause chronic fluorosis animal;

Fluorosis is mainly realized: (1) caused a decrease in the amount of poultry egg laying, egg fertilization rate, hatching rate decreased; (2) caused by decreased immunity of the animal breeding; inhibit oxidase, dehydrogenase activity and affect metabolism, resulting in animal weight loss and anemia; (3) caused by bone dystrophy, skeletal fluorosis, joint stiffness, stain teeth, enamel damage; (4) caused by cardiovascular disease, gastric cancer, lung cancer, or even death.

Arsenic poisoning: (1) and pyruvate oxidase of sulfur based combination makes the enzyme lost activity, affect the normal metabolism of the cells, leading to cell death; II do harm to nerve cells, causing multiple neuritis and central nervous breakdown and paralyze the capillaries, causing tissue dystrophy; (3) international cancer research institutions published arsenic carcinogenic factor; 4 acute arsenic poisoning can kill the animal in a short period of time; the chronic arsenic poisoning, as the hair becomes brittle and easy to fall off, muscle atrophy, pain in the limbs.

Chromium poisoning: in animals and nucleic acids, the nuclear protein binding, the phosphorus content of the affected tissue; II reduce amylase activity to prevent oxidation of cysteine enzyme; to the red cells carry oxygen function obstacles, have the effect of causing lung cancer, especially soluble in acid insoluble in water of chromium complexes are more dangerous.

Lead poisoning: early can make the cerebral cortex excitatory and inhibitory processes occurring in mild disorder and late serious disorder, caused by sympathetic and parasympathetic nervous system dysfunction; II interference from hemoglobin synthesis; (3) caused by intestinal paroxysmal spasm or paralysis; (4) induced interstitial nephritis, renal atrophy and reduce animal immunity; fifthly, can through breast milk into newborn carcasses during lactation, the destructive effects; sixthly, can pass through the placenta into the fetus, fetal harm;

Nitrite poisoning: according to foreign reports, in the process of fish meal production had used sodium nitrite as preservatives, if the amount is too large, can lead to raise animals nitrite poisoning may transformed into carcinogenic dimethylnitrosamine matter. Hebei Zhenyang (2005), He Jin (2006) and other relevant experts reported that toxic elements exceed the standard have toxicity following;

Cadmium poisoning: reduce broiler weight gain and lower feed conversion ratio; 2 pigs caused by anemia, causing sheep anemia, renal dysfunction; (3) caused by sperm of male animals lose activity; (4) caused by animals showing a lack of selenium, zinc deficiency symptoms and lesions, of animal cells and humoral immunity has inhibiting effect, reduce the immunity of animals;