Introduction to the classification of commonly used amino acids in feed additives

 In the full-price feed, in addition to the supply of energy and protein feed composition, due to the implementation of closed barn centralized feeding, but also need to provide livestock and poultry with a variety of vitamins, trace elements and other nutrients, and these ingredients in the general feed, the content is often insufficient, must be added separately. Usually the livestock, poultry need all kinds of amino acids, vitamins and trace elements, such as pre-mixed and formulated into additives, used for dosage. The following amino acids are briefly described: adult livestock, poultry for life-sustaining eight amino acids: lysine, methionine, tryptophan, valine, phenylalanine, leucine, isoleucine and threonine; growth stage of the livestock, poultry to ensure normal growth and development, in addition to the above essential amino acids, but also need histidine and arginine; young animals, young birds in addition to the above list, but also need glycine, cystine and tyrosine.

I. Lysine
     It can improve the utilization rate of protein and meat quality in animals. Soybean cake, fishmeal and bone meal are rich in lysine, if used with feed, then generally do not feel the lysine shortage. Corn (2446,11.00,0.45%), cottonseed cake, sesame oil cake, etc. for feed, protein utilization is low, when used to feed pigs, chickens, etc., you need to add an appropriate amount of lysine, usually in the barley, corn, add 0.2% to 0.3% lysine, so that its utilization of protein from 50% to 70% to 80%. About 90% of lysine is produced by molasses fermentation.

Methionine
    Methionine is a fortifying agent for food and feed, which has the function of improving the quality of lean meat, egg production rate and milk production, and its dosage accounts for about 0.05% to 0.30% of the feed amount. Test results show that adding 0.5kg of methionine to compound feed is equivalent to adding 25kg of fish meal. Methionine has been used for more than 20 years, and its development has been more rapid in the past 10 years. World methionine production annual growth rate of 29%. 1979 world methionine production reached 150kt, France's production of the world's top, followed by the Federal Republic of Germany, the United States, the Soviet Union, Mexico and Italy and other countries are also scrambling to build new factories to expand their productivity.

    The key to the development of methionine production lies in the production of raw materials acrolein and methyl mercaptan. Industrial synthesis of methionine with hydroxyl analog 2-tert-butyl-4,4-hydroxyanisole (MHA) can replace methionine, in the animal body MHA absorption of amino substituting hydroxyl and transformed into methionine. 1.2g MHA is equivalent to 1g methionine.

Tryptophan

    It can participate in the renewal of plasma proteins, promote the role of riboflavin, and help the synthesis of niacin and hemoglobin. Livestock and poultry lack of tryptophan, growth stagnation, weight loss, testicular atrophy of male animals. Due to the high production cost and poor economic efficiency, the annual production of tryptophan is only several hundred tons worldwide. It is mainly used as artificial milk additives for piglets, with an additive amount of 0.02% to 0.05%; a small part of it is used in the diets of sows and laying hens.