PROBLEM TO BE SOLVED: To provide methods for improving the quality of the hair of non-human animals.SOLUTION: The present invention involves methods for increasing the 18-methyleicosanoic acid content of the hair of a non-human animal by feeding to the animal an edible composition comprising an effective amount of an amino acid selected from the group comprising isoleucine, threonine, and mixtures thereof.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT