The rare earth element is composed of 17 elements, and the rare earth element and its compound have special physical and chemical properties. In China, some rare earth elements of salt and lanthanides (such as lanthanum and cerium) have been used as feed additives in livestock production for more than 40 years. A large body of literature has shown that the addition of a trace amount of rare earth mixture can increase pig body weight. In the past five years, many western countries have imported rare earth elements from China as feed additives for pig research. The results show that rare earth elements can increase the daily weight gain of pigs and increase the feed conversion rate. It is a new type of safe growth promoter. The application of rare earth elements in domestic aquaculture has proved that pigs fed a diet supplemented with rare earth elements with an average body weight of 7 kg (5 kg to 9 kg) can increase their body weight by 5% to 23%; feed conversion rate can be Increase by 4% to 19%. In the weight range of 13 kg to 17 kg, the body weight can be increased by 11% to 20%, and the feed conversion rate is increased by 5% to 9%. For growing and finishing pigs (30 kg ~ 50 kg), rare earth additives can increase their body weight by 9% to 13%, and feed conversion rate by 6% to 8%. In general, not certain specific rare earth elements are added to the feed, but rather a mixture of some of the constituents of lanthanum, cerium and lanthanum and some other lanthanides. Early studies mainly used the addition of nitrates and chlorides of these rare earth elements, and recent studies have mainly used the addition of organic salts such as citric acid and glucose, sometimes supplemented with amino acid methionine, lysine, and glutamine. class. Different studies used different concentrations. In China, pig feed is generally used at a concentration of 100 mg to 600 mg per kilogram. Larger concentration differences lead to a lack of comparability of research data, making understanding of the mechanism of action of rare earth elements more difficult. Rare earth elements are characterized by trace elements and can be classified as nutrient additives. They can also increase gastrointestinal digestibility and stabilize beneficial bacteria, and are regarded as probiotic additives. Anti Graffiti Powder Coating,Casting Powder Coating for Cast Iron,Powder Coating for Casting Aluminum Special Effect Powder Coating,Metallic Powder Coating Co., Ltd. , http://www.cdpowdercoating.com