Silver bay

Silver bay: how the color works and is inherited

Silver is a PMEL variant that lightens black pigment. A bay horse has most of that pigment in its mane, tail and lower legs, so those areas change most strongly.

One Silver copy is enough to lighten black pigment. A chestnut can carry Silver without visible dilution because its hair has no black pigment. Silver is also associated with MCOA eye abnormalities, generally more extensive with two copies.

Silver bay: origins and the role of breeding

Silver predates modern genetics: ancient DNA has identified this dilution in horse samples almost 3,000 years old. Researchers identified its connection to PMEL in 2006. Selective breeding has favored the color in some lines, using an existing variant rather than creating it from scratch.

Breeders can favor the pale mane by selecting parents. The same Silver variant produces silver black on a black base rather than representing two separately created dilutions.

• Ludwig et al. (2009) — Coat Color Variation at the Beginning of Horse Domestication
• Brunberg et al. (2006) — A missense mutation in PMEL17 is associated with the Silver coat color in the horse