Vitamins are low molecular weight organic chemicals. Vitamin is the catalyst of biochemical reaction and metabolism of the animal body. it is an indispensable micronutrient to maintain the normal physiological function and normal growth and development of animals. Vitamin is the earliest and most commonly used variety of feed additives.
I. Vitamins and their functions
Vitamins are divided into 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 and physiological role that can not be replaced by other substances.
1. Vitamin A
Vitamin A, also known as retinol, is a yellowish oil or crystalline highly unsaturated fatty alcohol, which can protect skin and mucous membrane. 1 unit of vitamin An is equal to about 0.3 micrograms. Most of the commonly used vitamin A are chemical synthetic products, such as vitamin A alcohol, vitamin A acetate and vitamin A palmitate, etc.
2. Vitamin D
Vitamin D, also known as ossifying alcohol or anti-rickets vitamin, is a kind of active substance related to calcium and phosphorus metabolism in animals, which can promote the absorption of calcium and phosphorus in the animal digestive tract. 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 kind of phenolic compound with biological activity, among which α-tocopherol has the highest titer and is the most commonly used. Vitamin E can regulate the metabolic function of the nucleus, promote gonadal development and improve reproductive ability. Vitamin E has the ability to absorb oxygen and its stability is not high. Esterification can improve its stability. Commonly used is vitamin E acetate.
4. Vitamin K
Vitamin K, also known as an anti-bleeding vitamin, is a kind of menadione derivatives. Vitamin K can promote the synthesis of prothrombin and achieve normal blood coagulation. Vitamin K has vitamin K1, vitamin K2, vitamin K3, and vitamin K4, etc., feed additives often use vitamin K3, general vitamin commodities often use the combination of vitamin K3 and sodium bisulfite, which is sodium bisulfite menadione.
5. Vitamin B1
Vitamin B1, also known as thiamine, is also known as anti-neuritis. Vitamin B1 can promote the metabolism of sugars and fats in the body. Vitamin B1 mainly exists in the form of salt, and thiamine hydrochloride is commonly used.
6. Vitamin B2
Vitamin B2 is also known as riboflavin or yolk. Vitamin B2 participates in the metabolism of proteins, carbohydrates, and nucleic acids in the body, and is a component of a variety of enzymes in biochemical reactions in the body.
7. Vitamin B3
Vitamin B3 is commonly known as nicotinic acid, also known as nicotinamide. Vitamin B3 is a component of coenzyme I and coenzyme II, which participates in the redox reaction.
8. Vitamin B4
Vitamin B4, also known as choline, is a component of phospholipids and acetylcholine, as well as a methyl donor. It participates in the metabolism of amino acids and fat and can prevent the production of fatty liver. Choline chloride is often used as a feed additive.
9. Vitamin B5
Vitamin B5 is commonly known as pantothenic acid, also known as anti-dermatitis vitamins. Vitamin B5 is a component of coenzyme An and plays an important role in material metabolism. Calcium pantothenate is often used in feed additives.
10. Vitamin B6
Vitamin B6 is the general name of three pyridine derivatives: pyridoxine, pyridoxal, and pyridoxamine. Vitamin B6 is a coenzyme in amino acid metabolism, which participates in the metabolism of protein, sugar, and fat. The commercial form of vitamin B6 is mostly pyridoxine hydrochloride, and pyridoxine hydrochloride is used as a feed additive.
11. Biotin
Biotin is also called vitamin H. Biotin is a coenzyme that participates in the metabolism of protein, fat, and so on. The commercial biotin is D-biotin, and the biotin H-2 commonly used in feed additives contains 2% D-biotin.
12. Folic acid
Vitamin B9, also known as folic acid and vitamin M, is a combination of stearic acid and glutamic acid. Vitamin B11 participates in the metabolism of protein and nucleic acid and promotes the formation of red blood cells, hemoglobin and antibodies together with vitamin B12 and vitamin C.
13. Vitamin B12
Vitamin B12, also known as cyanocobalamin, is a chelate containing cobalt atoms and cyanide groups. Vitamin B12 participates in protein metabolism, improves the utilization rate of plant protein, and is also an essential substance for the production of normal blood cells.
14. Vitamin C
Vitamin C is also called ascorbic acid. Vitamin C participates in the metabolism of sugar, protein, and mineral elements enhance immunity, and improves the activity of digestive enzymes. The vitamin C commonly used in feed additives is L-ascorbic acid and vitamin C polyphosphate with good stability.
II. Rational use of vitamin additives
Although the demand for vitamins is small, vitamins participate in a variety of metabolic processes and are catalysts for various biochemical reactions in the body. The effect of each vitamin on animals is irreplaceable by any other substance, and the lack of vitamins in animals will have obvious adverse consequences for growth and development. Therefore, the lack of vitamins must be added to the daily feed to meet the needs of the body.
1. Appropriate overuse
The stability of most vitamins is not high, and it is easy to cause loss and titer reduction in the process of feed processing and storage. In order to ensure that animals eat a sufficient amount of vitamins, they should generally be added in excess, that is, the added insurance coefficient of vitamins. Due to the different stability of different vitamins, the insurance coefficient is also different.
2. Choose vitamins
At present, vitamin preparations have a single vitamin and a variety of vitamin premixtures, according to the actual situation, we can determine whether to premix a variety of vitamins or buy multiple premixes. Multi-vitamin premixtures are widely used in small-scale production units. As the detection and quality judgment of vitamins are more complex, we should choose the products of professional manufacturers with a good reputation.
3. Pay attention to the effective content, titer and stability of vitamins
Most of the commercial vitamins sold in the market are not pure vitamins and 100% potency vitamins, such as vitamin E content of 50%, choline chloride of 50%, biotin of 2%, and the activity of calcium pantothenate is only 50%. Therefore, when choosing and using vitamins, we should pay attention to their effective content and potency, and convert them reasonably.
The stability of different forms of the same kind of vitamins is also different, such as vitamin A palmitate is more stable than vitamin An alcohol, vitamin E acetate is more stable than vitamin E alcohol, Thiamine nitrate is more stable than thiamine hydrochloride, vitamin C polyphosphate is more stable than vitamin C. Therefore, stable vitamins should be selected as far as possible in practical application.
4. Pay attention to the independent addition of choline and vitamin C
Because choline and vitamin C are easy to absorb moisture and destroy other vitamins, they are generally not pre-mixed with other vitamins and are added independently when in use. Most of the multi-dimensional preparations sold in the market do not contain choline and vitamin C. if you choose and use multi-dimensional preparations, you should pay attention to adding an appropriate amount of choline and vitamin C independently according to the feeding standard.
5. Adjust flexibly according to the actual situation
The feeding standard of vitamins should not remain unchanged but should be flexibly adjusted according to the actual formula, feeding environment, weather season, and other factors, so as to ensure the demand for vitamins in the actual situation and maintain a good state and production performance.
For example, the feed of laying hens with high calcium and phosphorus should appropriately increase the level of vitamin An and vitamin D in order to improve the absorption and utilization of calcium and phosphorus. The contents of vitamin E and biotin should be increased during the breeding period in order to maintain a good reproductive performance. High temperature and stress should increase the level of multiple vitamins, especially the content of vitamin C. If animals develop symptoms of vitamin deficiency, the level of vitamins should be improved.
6. Necessary dilution and preservation
Due to the low dosage of vitamins and the possibility of reacting with each other and with other additives, it is best to dilute the vitamins by a large multiple before application, reduce the concentration, and then premix with other vitamins and additives.
Especially when premixed with choline, trace elements, and acid-base additives, dilution should be done to ensure better mixing uniformity and higher titer. The commonly used carrier for vitamin dilution and premixing is defatted corn starch. Vitamin products are sensitive to light and heat and other external factors, and are easy to fail, so they should be stored in a low-temperature, airtight and dry environment. It should be used as soon as possible after opening, and the preservation period should not exceed 1 month.