What are the functions and advantages of organic trace elements zinc, copper, manganese and selenium?
Trace elements are essential nutrients for animals to maintain life and produce. One of its characteristics is that the dosage is small but the effect is large. Although the content of trace elements in organisms is less than 0.01%, they participate in almost all physiological and biochemical processes of the body and are closely related to animal growth and health. They participate in the formation and activation of enzymes, vitamins and hormones in animals; they also participate in regulating material metabolism, and determine the growth, development and reproductive functions of the body, as well as the production efficiency and product quality of animals. Therefore, the supply, absorption and utilization of trace elements are crucial.
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The role of trace elements
1.1 Zinc, copper, manganese and leg and foot disease in dairy cows
Hoof disease is one of the three major diseases in dairy farming, causing huge losses to dairy farmers every year. Therefore, controlling hoof diseases through feeding management and dairy cow nutritional management is also a focus of dairy farming.
1.1.1 Zinc and foot and limb disease
Zinc is a component of various enzymes and proteins in the animal body. It can participate in a variety of metabolic reactions and is one of the key mineral elements in the process of hoof keratinization. Zinc participates in the activation of enzymes that catalyze keratinocyte differentiation. At the same time, the synthesis of keratin and cutin is also inseparable from zinc, which can enhance the hardness and integrity of the hoof; zinc is involved in the formation of collagen, which directly participates in the division of primitive cartilage cells, thereby affecting bone calcification. The zinc content in bones affects bone density. The higher the zinc content, the greater the bone density, and vice versa. When zinc is deficient, animals will develop skin parakeratosis, reduced hoof hardness and integrity, hoof shell deformation and cracking, abnormal bone development and other pathological phenomena.
1.1.2 Copper and limb and foot disease
Copper is a component of a variety of enzymes. Copper can activate cytochrome oxidase, lysyl oxidase, sulfhydryl oxidase, thiol oxidase, amino oxidase, etc. Copper deficiency will lead to insufficient amounts of the above enzymes, resulting in insufficient energy supply to keratinocytes; affecting the integrity of hoof keratinocytes; affecting the structural strength of the keratinocyte matrix; affecting the formation of isolockin and locks. Therefore, copper plays an important role in the formation of bones and cutin. Copper deficiency in dairy cows can easily lead to hoof diseases such as hoof cracks, foot rot, and sole abscesses.
1.1.3 Manganese and foot and limb disease
Manganese is an activator of many enzymes. Manganese deficiency in dairy cows will lead to insufficient enzymes that promote the synthesis of acid mucopolysaccharides in cartilage and bone matrix, thereby affecting the synthesis of cartilage and collagen. Manganese deficiency in dairy cows will lead to sulfation of proteoglycan molecules. Side chain synthesis of chondroitin, an important component of normal cartilage and bone, is affected. Manganese deficiency in dairy cows will lead to insufficient synthesis of carbohydrates that provide energy for hoof keratinocytes, thereby affecting the keratinization of hoof keratinocytes. When animals are deficient in manganese, cartilage growth is impaired, leading to skeletal deformities. The deposition of other inorganic substances in bones is also affected by manganese. Therefore, manganese deficiency in dairy cows can cause deformation of limb bones and joints, leading to limb and foot disease.
1.2 Zinc, copper, manganese, selenium and oxidative stress
Oxidative stress refers to the excessive production of highly active molecules such as reactive oxygen free radicals and reactive nitrogen free radicals in the body when the body is subjected to various harmful stimuli. The degree of oxidation exceeds the removal of oxides, and the oxidation system and antioxidant system are out of balance. , resulting in tissue damage, which is an important factor leading to morbidity and aging of the body. The stronger the body’s ability to resist oxidative stress, the less susceptible dairy cows are to disease.
1.2.1 Zinc and oxidative stress
Zinc plays an important role in the resistance of organisms to oxidative stress. Zinc can prevent metal ions from reacting with hydrogen peroxide and superoxide to generate hydroxyl radicals. Zinc is one of the important metal prosthetic groups of copper/zinc-superoxide dismutase (Cu/Zn-SOD). Zinc deficiency will significantly reduce Cu/Zn-SOD activity. Zinc can activate glutathione peroxidase (GSH-Px) in the body and reduce free radicals in the body. Zinc deficiency will reduce the amount of active GSH-Px in the organism, leading to increased lipid peroxidation, thereby increasing GSH-Px consumption and reducing activity. Zinc can also induce the liver to synthesize metallothionein (MT), thereby resisting free radical damage.
1.2.2 Copper and oxidative stress
An appropriate amount of copper has the effect of resisting oxidative stress in the body. Copper is an essential component of ceruloplasmin, which has the effect of resisting free radical damage; copper is the active center of copper/zinc-superoxide dismutase (Cu/Zn-SOD) in the enzyme antioxidant system. Copper deficiency will lead to a significant reduction in the content of ceruloplasmin and the activity of Cu/Zn-SOD, thereby causing the body to��Less amount of trace elements is used, which is safer and more efficient.
2.2 Reduce mutual antagonism between mineral elements
Inorganic trace elements are unstable and easy to combine, and are more likely to interact than other substances. These effects occur between feeds. There are many antagonisms between trace elements in the digestive tract tissue and cell metabolism, and between macroelements in absorption and excretion, transport metabolism, and functional performance. The main forms of this antagonism that occur in the digestive tract are: ① Simple chemical reactions between elements. If there is too much magnesium in the diet, magnesium phosphate can be formed in the digestive tract, thereby hindering the absorption of phosphorus. ② Adsorbed by colloidal particles. For example, iron and manganese have the same electron orbit, configuration and coordination number, and can be fixed on the surface of insoluble magnesium salts or aluminum salts, thereby reducing the absorption of iron and manganese in the digestive tract. ③Ions compete for carriers on the intestinal wall. Both copper and zinc are absorbed in the small intestine. They can compete with each other for binding sites in metallothionein or intestinal mucosa, resulting in mutual inhibition of absorption. The absorption of organic trace elements in the animal body is different from that of inorganic salts. Amino acids and protein chelates use the absorption mechanism of peptides and amino acids to be absorbed in the form of amino acids or peptides. Therefore, there is no mutual antagonistic effect, so the dosage is more controllable and reasonable.
2.3 Avoid antagonism with anti-nutritional factors in feed
Inorganic trace elements can combine with fiber, phytic acid, etc. to form a stable structure in the intestines of animals. For example, neutral detergent fiber (NDF) can combine with divalent iron to affect absorption; phytic acid can combine with divalent copper , iron, and zinc combine to form precipitation, thereby reducing absorption; while the metal ions in organic trace elements are located in the center of the chelate, and after combining with the ligands through coordination and covalent bonding, their intramolecular charges tend to be neutral, forming a stable Structure, will not be combined with anti-nutritional factors in the diet to affect absorption.
2.4 Stronger ability to resist oxidation and improve immunity
A large number of studies in recent years have shown that organic trace elements are superior to inorganic salt trace elements in improving immune function, improving intestinal health and reducing stress. It can enhance the body’s anti-pain ability, maximize the body’s immune response, promote cellular immunity and humoral immunity, and play an anti-stress and anti-disease role.
2.5 Chemically stable
In inorganic salt molecules, anions and cations form unstable ionic bonds through static electricity, so they are easy to react chemically with other substances, and the chemical structure is extremely unstable; while organic traces are centered on trace element ions, and the amino acids in amino acids are Oxygen and nitrogen atoms wrap around the trace elements, sealing the trace elements, which makes it have relatively stable chemical properties, and also makes the charge within the molecule tend to be neutral, which can effectively protect metal ions in the body, thereby preventing metal ions from avoiding Reacts adversely with substances such as gastric acid in the gastrointestinal tract and other ingredients in the diet. In particular, amino acid chelates are bonded through coordination covalent bonds, and their stability is higher than complexes bonded through ionic bonds.
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Conclusion
Trace elements are indispensable nutrients for dairy cows. Both excess and deficiency will have adverse effects on the body. Compared with inorganic trace elements, organic trace elements have a promoting effect on increasing dairy cows’ feed intake, increasing growth rate and fecundity, improving product quality and body immunity, antioxidant function, reducing stress, etc.; its better Safety and stability can effectively avoid the damage of trace elements to other nutrients, reduce the antagonism of trace elements, and improve the utilization efficiency of trace elements and breeding safety.
