Compound formula of butyrate and derivatives thereof and benzoic acid, and preparation method therefor and application thereof as feed additive

Use of a composition of a butyrate or a derivative thereof and benzoic acid as a feedstuff additive, wherein the composition of the butyrate and benzoic acid is added to the feedstuff in an amount of 0.1 wt % to 0.5 wt %;

• upon reaching the stomach of an animal, the composition of the butyrate and benzoic acid dissociates into butyric acid and benzoic acid molecules;
• the butyric acid stimulates parietal cells to grow and the parietal cells produce hydrochloric acid, which thereby reduces the pH value in the stomach to a range of 2.5-4.0, at which the benzoic acid can perform an optimal preservative effect and antimicrobial activity, rendering a butyric acid-producing anaerobic flora become a predominant microflora, which produces more endogenous organic acids, such as lactic acid and butyric acid;
• and consequently, a combination of butyric acid and benzoic acid can produce a synergy effect.

A method for preparing a composition of a butyrate or a derivative thereof and benzoic acid, comprising adding water to a reactor, then adding a hydroxide into the reactor under continuous stirring until the hydroxide is completely dissolved, gradually adding benzoic acid and dissolving it under stirring, then adding the butyric acid under continuous stirring and controlling the temperature of the reaction solution not higher than 105° C. to produce a mixed solution of the butyrate and a benzoate, cooling the reaction solution to a temperature of 60° C.-90° C. after completing the reaction;

• adjusting the pH value of the reaction solution to 8-10 by adding an appropriate amount of butyric acid or a basic salt;
• adding dextrin to the reaction solution in the reactor and dissolving it or forming a suspension under stirring, continuously cooling the reaction solution to a temperature of 25° C.-50° C.;
• then spray-drying the resulting mixture under an inlet air temperature of 150° C.-260° C. and an outlet air temperature of 65° C.-160° C., and finally, collecting dry powders via a cyclone separator or a vibrated fluidized bed to obtain microspheric particles of the butyrate and benzoic acid (benzoate).