Biological Feed Additives: Fight Against Antibiotics
Dispersing Agent,Agricultural Dispersant,Viscosity Reduction Dispersant,Wetting Dispersing Agent Jiangxi Tiansheng New Materials Co.,Ltd , http://www.jxtsxcl.com
The ruminant animal's rumen can produce a strong urease, and urea is rapidly hydrolyzed by urease to produce ammonia and carbon dioxide. The ammonia can be biosynthesized by rumen microorganisms to generate microbial protein, which is then digested and absorbed by the animal. Almost all bacteria in the rumen can use various forms of ammonia, ie nitrogen to synthesize microbial proteins. The ammonia in the rumen fluid is mainly derived from the protein in the diet, microbial protein and non-protein nitrogen degrading substances, and the recycling process of urea through the rumen wall. Under the action of microbial enzymes, most of the protein in the diet is hydrolyzed into peptides and amino acids. Some of them are transformed into microbial proteins, and some of them are deamidated to produce ammonia and volatile fatty acids. After the volatile fatty acids are absorbed, they serve as carbon scaffolds for the synthesis of amino acids. The addition of non-protein nitrogen to the feed can allow ruminants that consume roughage, which have lower levels of protein, to maintain a certain concentration of ammonia in the rumen for the use of microorganisms to synthesize proteins for use by the host, thus partially addressing diets. Insufficient protein. In addition, the addition of non-protein nitrogen can maintain a certain concentration of ammonia in the rumen, reduce the hydrolysis of dietary protein by microorganisms, thereby increasing protein utilization.
However, due to the high efficiency and specificity of urease, urea in the rumen decomposes rapidly after eating feed containing urea. The rate of urea decomposition can be up to four times the rate at which microorganisms use ammonia, which, in turn, results in the waste of urea ammonia and ammonia poisoning in animals due to high ammonia concentrations in the rumen. Therefore, in the use of non-protein nitrogen feed such as urea, urease inhibitors need to be added to reduce the loss of urea nitrogen and prevent ammonia poisoning.
2. Types of urease inhibitors Urease inhibitors are special substances used to reduce urease activity. They inhibit microbial urease activity in the rumen of ruminants, slow down the rate of decomposition of urea, and provide a balanced supply of ammonia nitrogen to the rumen microorganisms, thus increasing ruminant Urea utilization. The substances that can be used as urease inhibitors generally have the following types:
1. Acetohydroxamic acid (abbreviated as AHA) is a white or pale yellow crystalline substance obtained by chemical synthesis. The melting point is 88-92°C. The aqueous solution is slightly acidic, easily absorbing moisture, easily discolored in case of light, and easily soluble in water. Ethanol, ether and so on. Acetohydroxamic acid (AHA) is a very effective urease inhibitor, which can inhibit rumen microbial urease activity, regulate rumen microbial metabolism, increase microbial protein synthesis (25%) and cellulose digestibility, and reduce the rate of urea decomposition in the rumen. .
2. Hydroquinone (HQ), also known as hydroquinone, [C6H4(OH)2] molecular weight l10.10, dihydric phenol, is a white crystal. The boiling point is 286.2°C, soluble in water and compatible with alcohol in any ratio. Its role is mainly used to inhibit urease activity in soil.
3. Benzoquinone, [C6H4O2] molecular weight 108.10, this product is a yellow crystal; a special odor; sublimation. Dissolved in ethanol or ether, slightly soluble in water.
4. Sodium tetraborate (Na2B4O710H2O), also known as borax, is a colorless translucent crystal or white monoclinic crystalline powder. Odorless and salty. The relative density was 1.73; eight crystal waters were lost at 60°C, and all crystal waters were lost at 350-400°C. Soluble in water, glycerol, slightly soluble in alcohol, aqueous solution is weakly alkaline.
5. Heavy metal salts generally include heavy metal ions such as Mn2+, Ba2+, Co2+, Cu2+, and Fe2+. Among them, Mn2+ and Ba2+ work best, but these ions also inhibit the activity of other enzymes.
Third, the role of urease inhibitors Different types of urease inhibitors, the mechanism of urease inhibition is not the same. It is currently believed that oxindoles (especially acetohydroxamic acid) are the most effective inhibitors of urease (Mapadevan, 1976). Acetate is an N-hydroxyacetamide with the formula CH3-CO-NHOH. The molecular weight is 75.05. Acetohydroxamic acid has a hydroxylamine structure (-NHOH) in its molecule and its active hydrogen and hydroxyl groups combine with the thiol group (-SH) adjacent to the metal nickel (Ni) in the urease molecular structure to form a urease inhibitor-urease binary complex As a result, urease activity was inhibited. The urease inhibitor is not bound to the binding group at the active site of the urease, but binds to the catalytic group at the active center of the urease and inhibits the activity of the enzyme by changing the conformation of urease.
It can be seen that the inhibitory effect of acetohydroxamate inhibitor on urease production is a reversible non-competitive inhibition, that is, the inhibitor does not affect the binding of urease to the substrate (urea) and does not change the Michaelis constant (Km) of urease ( That is, without changing the affinity of the enzyme with the substrate), the reaction rate (V) of the urease-catalyzed substrate is simply decreased. This will ensure that urea (exogenous urea and endogenous urea) can still be hydrolyzed by urease in the rumen, slowly releasing ammonia to meet the nitrogen requirement for rumen microbial proliferation.
Fourth, the market and development direction Urease inhibitors as a new type of feed additives in foreign countries (such as the United States, Canada, etc.) has been widely used. In recent years, it has also begun to pay attention to the synthesis and application of urease inhibitors. Urease inhibitors have been listed as the promotion project of the Ministry of Agriculture and the Ministry of Science and Technology and have become one of the key projects for the new century-long new technologies. The development and application of urease inhibitors will provide new technical guarantees for China's high-efficiency agriculture, and will be of great significance in adjusting the industrial structure of animal husbandry and vigorously developing herbivorous livestock breeding. From the current situation of research and application, oxoguanidin urease inhibitors have good application effects, simple operation, low cost and large market potential. They are a kind of feed additives with development and application prospects. With the advancement of science and technology, people will pay more attention to the issues related to the application of urease inhibitors and carry out more in-depth studies to make them more perfect. At the same time, more and more effective urease inhibitors should be further studied and screened in order to achieve better results in improving the production of ruminants. In order to meet the needs of the animal husbandry industry and the market, Shanghai Three-dimensional Feed Additives Co., Ltd. recently introduced the urease inhibitor "Cattle and Sheep Music" to the market. "Cattle and Sheep Music" is based on acetohydroxamic acid (AHA), supplemented with certain nutrients required for ruminants, and is scientifically formulated. The product is now approved by the customer, which brings good economic benefits to the customer.