Although there are many mineral elements in animals, they are not all mineral elements necessary for animals. The essential mineral elements are divided into two categories according to the requirements of animals: macroelements, whose requirements are generally greater than 100 mg/kg of the diet, usually expressed as a percentage of the diet. Major elements include calcium, phosphorus, potassium, magnesium, sodium, sulfur, chlorine. For trace elements, the required amount is generally less than 100 mg/kg in the diet, and the content in the feed is often expressed in mg/kg.
 
Although there are many types of trace elements, the currently recognized ones are chromium, cobalt, copper, iodine, iron, manganese, molybdenum, selenium and zinc.

 
In the formulation of diets, trace elements are usually added in the form of their compounds or complexes (chelates) to meet the requirements of feed standards. We usually call trace elements from inorganic compounds such as ferrous sulfate, manganese sulfate, copper sulfate, zinc oxide, cobalt chloride, potassium iodide, and sodium selenite as inorganic trace elements; The trace elements of organic complex (chelate) compounds such as amino acid manganese and zinc lysine are called organic trace elements.
 
1. The disadvantages of inorganic trace elements
Inorganic trace elements are cheap and cost-effective, but cost-effective. Compared with organic trace elements, it has many disadvantages.
1.1. The utilization rate is too low. After inorganic trace elements enter the intestinal tract, they need to find ligands for absorption.
1.2. There is antagonism between inorganic mineral elements. Mineral elements compete for absorption channels in the digestive tract, and one mineral element can significantly affect the absorption of one or several mineral elements.
1.3. Pure inorganic micro-minerals have damage to some nutrients (such as vitamins). Numerous micro-minerals will destroy vitamins to varying degrees; in addition to destroying vitamins, high copper content can also make the oxidative rancidity problem of refueled concentrated feed more serious; inorganic trace elements will act as catalysts for oxidation reactions in the body, aggravating the occurrence of oxidation reactions in the body , affecting animal health.
1.4. The dosage is large, the palatability is poor, and the environment is polluted. The rate and pattern of metabolism will change during special periods of animal growth and development, reproduction, stress, disease, etc. If it is supplemented in the form of conventional metal inorganic salts, the wrongly multiplied capacity cannot meet the needs. High inorganic minerals will significantly increase the excretion of feces, pollute the environment, and endanger the health of humans and animals.
 
2. The advantages of organic trace elements
Organic trace elements are expensive and cost-effective, but cost-effective. Compared with inorganic trace elements, it has the following advantages:
2.1. Organic micro-minerals are better absorbed. They can be absorbed by the body without looking for ligands. They will not be neutralized by antagonistic substances in the body. competition between.
2.2. Organic micro-minerals, quick replenishment for peak demand. After amino acids and metal ions are combined into an organic whole, there will be no mutual inhibition or resistance; organic trace minerals are more likely to adhere to amino acids, peptides and other compounds, so it is easier to enter biological systems; Absorption modality improves absorption, storage, and release in the body to meet peak body needs in time and quantity.
2.3. The addition of organic trace elements to the feed can significantly improve the production and reproductive performance of animals. Experts and scholars at home and abroad have done in-depth and meticulous research.
2.3.1. Study on chelated iron in sows and suckling piglets: 2.3.1.1. Xu Li (1994) studied the diet of iron glycinate (150mg/kg), and piglets could obtain the same iron content without any iron supplementation after production. The same growth and anti-anemia effect of intramuscular dextrose.
2.3.1.2.Close (2001) found that adding organic iron to the diet of pregnant sows or lactating sows increased the weaning weight of piglets and increased Hb in blood, proving that organic iron can easily enter the embryo through the placenta.
2.3.1.3. British Darneley (1993) study reported that the sows began to eat organic iron (56.7g/head·d) 28d before parity 1 to 8 parity, and the average number of weaned piglets per litter increased by 7.1%, and the number of piglets was increased by 7.1%. The mortality rate decreased by 26.8%.
2.3.2. Application effect of chelated trace elements on weaned piglets:
2.3.2.1. The application of organic trace elements to weaned piglets has a significant effect. Ward test confirmed that adding 250mg/kg of zinc methionine can increase the growth rate, feed intake and feed conversion rate of weaned piglets by 5%-8%, 3%-4% and 1%-11%, respectively, and increase the body weight at the end of the nursery period by 0.63～ 0.90kg.
2.3.2.2. Ji Sunrui (2002) showed that organic trace elements can significantly improve the daily weight gain of weaned piglets, and using organic trace elements to replace 40% of inorganic trace elements is also better than using all inorganic trace elements.
2.3.3. Application effect of chelated trace elements in growing-finishing pigs: adding organic trace elements makes growing-finishing pigs increase daily weight gain and feed utilization rate, promote growth, improve carcass quality, enhance physique, and improve disease resistance . Qin Yizhi (2000) studied the effect of applying organic trace element complexes in feed. The results showed that the weight gain was increased by 8.59%, the feed utilization rate was improved by 6.40%, and the cost was saved by 0.26 yuan per 1kg of weight gain.
2.3.4. Application effect of organic trace elements on laying hens:
2.3.4.1. Amino acid iron (Tang Shengqiu et al. 2003) 375d Roman laying hen, iron supplementation in corn and soybean meal type diet
Ferrous sulfate 80ppm →→ egg breaking rate 4%～5%
Ferrous sulfate 600ppm →→ Significantly improve egg breaking rate
Ferrous glycinate 80ppm →→ Significantly reduce egg breaking rate
2.3.4.2. Amino acid manganese (Manangi et al., 2015): Supplementation of methionine hydroxyl analog chelated zinc copper manganese he sulfate in basal diets to compare the effect of manganese source and manganese level on Hy-Line W-36 laying hens . It was found that the organic group (40-10-40ppm) significantly improved eggshell strength (68 weeks) and eggshell thickness (74 weeks) compared to the inorganic group (80-10-80ppm). Organic manganese is better than inorganic manganese.
2.3.4.3. Amino acid zinc (Xu Jiaping, 2012): Studies have found that zinc affects the strength of eggshells by regulating the activity of alkaline phosphatase in eggshell glands and at the same time affecting the activity of carbonic anhydrase. The calcium level in the laying hen feed is high, and calcium has a occupancy inhibitory effect on the absorption of zinc, thereby affecting the activity of carbonic anhydrase and reducing the strength of eggshells. Zinc methionine can alleviate the antagonistic effect of high calcium on zinc absorption, so it is better than zinc sulfate to improve eggshell quality.
2.3.4.4. Amino acid copper manganese zinc (Macial et al., 2010; Zhao Bo et al., 2005): 72-80 weeks old Hisex hens, while using organic zinc, organic copper and organic manganese to replace 50% of inorganic zinc, copper and manganese respectively, Eggshell loss can be minimized. 160-day-old Roman powder, added with different trace amounts (ppm) of inorganic iron 60, copper 20, manganese 100, zinc 80, selenium 0.3, iodine 0.4 methionine iron 30, copper 10, manganese 50, zinc 40, selenium 0.15, iodine 0.2 Inorganic iron 30, copper 20, manganese 100, zinc 80, selenium 0.3, iodine 0.4 methionine micro-replacement 50% significantly improved eggshell quality and improved the disease resistance of chickens.