Vitamins, also known as vitamins, are a class of low-molecular-weight organic chemicals. Vitamins are catalysts for biochemical reactions and metabolism of animals, and are an indispensable micronutrient for maintaining normal physiological functions and normal growth and development of animals. Vitamins are the earliest and most commonly used varieties of feed additives.
1. Commonly used vitamins and their functions
Commonly used vitamins are divided into two categories: fat-soluble vitamins and water-soluble vitamins. Fat-soluble vitamins include vitamin A, vitamin D, vitamin E, and vitamin K, and water-soluble vitamins include vitamin B, vitamin C, and so on. Each vitamin plays a special nutritional physiological role that cannot be replaced by other substances.
1. Vitamin A
Vitamin A, also known as retinol, is a kind of highly unsaturated fatty alcohol in yellowish oily or crystalline form, which can protect the skin and mucous membranes. The unit of measurement is u. 1 unit of vitamin A is about 0.3 micrograms. Commonly used vitamin A is mostly chemically synthesized products, including vitamin A alcohol, vitamin A acetate and vitamin A palmitate, etc., and vitamin A palmitate is mostly used in feed additives.
2. Vitamin D
Vitamin D, also known as calciferol or anti-rickets vitamin, is a kind of active substance related to the metabolism of calcium and phosphorus in animals, which can promote the absorption of calcium and phosphorus in the digestive tract of animals. There are many forms of vitamin D, among which vitamin D2 and vitamin D3 are more important and commonly used. Vitamin D3 is often used in feed additives.
3. Vitamin E
Vitamin E, also known as tocopherol, is a class of biologically active phenolic compounds, of which α-tocopherol has the highest potency and is the most commonly used. Vitamin E can regulate the metabolic function of the nucleus, promote gonadal development and improve reproductive capacity. Vitamin E has the ability to absorb oxygen, and its stability is not high, and its stability can be improved by esterification. Commonly used is vitamin E acetate.
4. Vitamin K
Vitamin K, also known as anti-bleeding vitamin, is a class of menaquinone derivatives. Vitamin K can promote the synthesis of prothrombin and achieve normal blood coagulation. Vitamin K includes vitamin K1, vitamin K2, vitamin K3 and vitamin K4, etc. Feed additives mostly use vitamin K3, and general vitamin products use the combination of vitamin K3 and sodium bisulfite, namely sodium bisulfite menadione.
5. Vitamin B1
Vitamin B1, also known as thiamine, is also known as an anti-neuroinflammatory hormone. Vitamin B1 can promote the metabolism of carbohydrates and fats in the body. Vitamin B1 mainly exists in the form of salt, and thiamine hydrochloride is generally used.
6. Vitamin B2
Vitamin B2 is also known as riboflavin or vitelline. Vitamin B2 is involved in the metabolism of proteins, carbohydrates and nucleic acids in the body, and is a component of various enzymes in biochemical reactions in the body.
7. Vitamin B3
Vitamin B3 is commonly known as pantothenic acid, also known as anti-dermatitis vitamin. Vitamin B3 is a component of coenzyme A and plays an important role in material metabolism. Calcium pantothenate is often used in feed additives.
8. Vitamin B4
Vitamin B4, also known as choline, is a component of phospholipids and acetylcholine, and is also a donor of methyl groups. It participates in the metabolism of amino acids and fats, and can prevent the production of fatty liver. Choline chloride is often used in feed additives.
9. Vitamin B5
Vitamin B5 is commonly known as niacin or niacin, also known as niacinamide or niacinamide. Vitamin B5 is a component of coenzyme I and coenzyme II, and is involved in redox reactions.
10. Vitamin B6
Vitamin B6 is a general term for three pyridine derivatives, pyridoxine, pyridoxal and pyridoxamine. Vitamin B6 is a coenzyme in amino acid metabolism and is involved in the metabolism of protein, sugar and fat. The commercial form of vitamin B6 is mostly pyridoxine hydrochloride, and pyridoxine hydrochloride is mostly used as a feed additive.
11. Vitamin B11
Vitamin B11, also known as folic acid and vitamin M, is a combination of pteroic acid and glutamic acid. Vitamin B11 is involved in the metabolism of proteins and nucleic acids, and can work with vitamin B12 and vitamin C to promote the formation of red blood cells, hemoglobin and antibodies.
12. Vitamin B12
Vitamin B12, also known as cyanocobalamin, is a chelate compound containing cobalt atoms and cyano groups. Vitamin B12 participates in protein metabolism of the body, improves the utilization rate of plant proteins, and is also an essential substance for normal blood cell production.
Biotin is also called vitamin H. Biotin is a coenzyme involved in the metabolism of proteins, fats, etc. The commercialized biotin is D-biotin, and the commonly used biotin H-2 for feed additives contains 2% D-biotin.
14. Vitamin C
Vitamin C is also called ascorbic acid. Vitamin C participates in the metabolic process of sugar, protein and mineral elements, enhances the body’s immunity, and improves the activity of digestive enzymes. Vitamin C commonly used in feed additives is L-ascorbic acid and vitamin C polyphosphate with better stability.
Second, the rational use of vitamin additives
Although the demand for vitamins is relatively small, vitamins are involved in various metabolic processes in the body and are catalysts for various biochemical reactions in the body. The effect of each vitamin on animals is irreplaceable by any other substance. If animals lack vitamins, there will be obvious adverse consequences for growth and development. Therefore, the lack of vitamins must be added to the daily feed for the body’s needs.
1. Determination of vitamin feed standards
The feeding standard of vitamins is the requirement value of animals for various vitamins. In the 1980s, our country has formulated the vitamin feeding standards for some animals, but it has not been updated for many years. Now the most complete variety and data is the NRC (National Research Council) standard of the National Academy of Sciences. The NRC standard is the most basic requirement of vitamins for animals, which can prevent obvious vitamin deficiencies. However, the optimal requirements of animal vitamins formulated by some professional vitamin manufacturers refer to the amount added to enable animals to obtain the best health and production performance. The optimal vitamin requirements of these factories are generally several to dozens of times higher than the NRC standard. Therefore, when designing and applying vitamin additives, the feeding standard of vitamins should be reasonably determined, which is generally higher than the NRC standard and can be used when conditions permit. Best demand criteria. It is necessary to consider the influence of various factors such as feed variety, animal health status, feeding environment, formula cost, storage time, etc., and master it flexibly and scientifically to meet the greatest needs of animal growth and development as much as possible. Especially in stressed animals, the vitamin level of the feed should be increased.
2. Appropriate excess application
Most of the vitamins are not stable, and it is easy to cause losses and lower titers during the processing and storage of feeds. In order to ensure that the animals eat enough vitamins, they should generally be added in excess, that is, the added insurance factor of vitamins. Due to the different stability of different vitamins, their insurance factors are also inconsistent.
3. Choose vitamin preparations
At present, there are single vitamins and multivitamin premixes in vitamin preparations. When applying, it can be determined whether to premix multiple single vitamins by yourself or purchase multiple premixes according to the actual situation. Small production units use more multivitamin premixes. Because the detection and quality judgment of vitamins are more complicated, the products of professional manufacturers with good reputation should be selected.
4. Pay attention to the effective content, potency and stability of vitamins
Most commercial vitamins are not pure and 100% potency vitamins, such as vitamin E content is mostly 50%, choline chloride is 50%, biotin is 2%, D-pantothenate calcium is only 50% active. Therefore, when purchasing and applying vitamins, attention should be paid to their effective content and potency, and they should be converted reasonably. Different forms of the same vitamin have different stability. For example, vitamin A palmitate is more stable than vitamin A alcohol, vitamin E acetate is more stable than vitamin E alcohol, nitrothiamine is more stable than thiamine hydrochloride, and vitamin C is more stable than vitamin E alcohol. Polyphosphates are more stable than vitamin C. Therefore, in practical applications, stable vitamins should be used as much as possible.
5. Pay attention to the independent addition of choline and vitamin C
Since choline and vitamin C are easy to absorb moisture and destroy other vitamins, they are generally not premixed with other vitamins, and then added independently when used. Most of the multi-dimensional preparations on the market also do not contain choline and vitamin C. If multi-dimensional preparations are selected and used, it should be noted that appropriate amounts of choline and vitamin C should be added independently according to the feeding standards during application.
6. Flexible adjustment according to the actual situation
The feeding standards of vitamins should not be static, but should be flexibly adjusted according to the actual formula variety, feeding environment, weather and seasons, etc., to ensure that animals need vitamins under actual conditions and maintain a good state and production performance. For example, in the feed of laying hens with high calcium and phosphorus, the levels of vitamin A and vitamin D should be appropriately increased to improve the absorption and utilization of calcium and phosphorus. During the breeding period of animals, the content of vitamin E and biotin should be increased to maintain better reproductive performance. High temperatures and stressful conditions should increase levels of multivitamins, especially vitamin C. Animals have symptoms of deficiency of the corresponding vitamin, and the level of the corresponding vitamin should be increased.
7. Necessary dilution and preservation
Due to the small amount of vitamins, in addition, they may react with each other and with other additives to destroy the potency. Therefore, it is best to dilute a larger multiple before application, reduce the concentration, and then premix with other vitamins and additives. Especially when premixing with choline, trace elements and acid-base additives, dilution should be done to ensure better mixing uniformity and higher potency. A common carrier for vitamin dilution and premixing is defatted cornstarch. Vitamin products are more sensitive to external factors such as light and heat, and are prone to failure. Therefore, they should generally be stored in a low temperature, airtight, and dry environment. It should be used as soon as possible after opening, and the shelf life should generally not exceed 1 month.