Use of gamma-quaternary ammonium butyrate compound in preparation of an animal feed additive

A method of improving animal production performance, the method comprising administering an animal feed additive to an animal, wherein the animal is selected from livestock and poultry;

• wherein the improved production performance of the animal is improved weight gain or feed conversion efficiency compared to an animal not administered with the animal feed additive, and wherein the animal feed additive comprises a γ-quaternary ammonium butyrate compound having Formula (I), or a racemate, a stereoisomer, a geometric isomer, a tautomer, a solvate or a feed acceptable salt thereof,
• wherein A is an anion;
• R is C1-C20 alkyl, C6-C12 aryl, C4-C12 heteroaryl, (C1-C4 alkylene)-C6-C12 aryl, or (C1-C4 alkylene)-C4-C12 heteroaryl, wherein C1-C20 alkyl is optionally substituted with one, two, three, four, or five R3, and wherein each of C6-C12 aryl, C4-C12 heteroaryl, (C1-C4 alkylene)-C6-C12 aryl, and (C1-C4 alkylene)-C4-C12 heteroaryl is optionally substituted with one, two, three, four, or five R4;
• R3 is —OH, —NH2, —CN, —SH or —X1, wherein X1 is F, Cl, Br or I;
• and
• R4 is —OH, —NH2, —NO2, —CN, —SH, —X2, —C1-C5 alkoxy, —C1-C5 alkyl, or —C1-C5 alkyl substituted with X2, wherein X2 is F, Cl, Br or I.