In donkeys, the Dun coat is characterized by a diluted colour, often grey or light chestnut, accompanied by darker markings such as a dorsal stripe. Dun is a dominant trait: a single copy of the Dun allele is sufficient for the diluted coat colour to be expressed. In contrast, non-Dun donkeys have a non-diluted coat colour, such as black or chestnut. The genetic test determines whether the animal is Dun or non-Dun.
