Multiple Spurs

The multiple spur gene in chickens causes the cock birds to grow a minimum of three separate spurs from the shank. (4) There is typically one large, central spur, one above the large spur, and then a smaller immediately below the central spur (1). While three spurs are the most common, chickens with the multiple spur gene can have up to five spurs on each shank (6). This trait can be seen on hens as three separate, enlarged scales on the shank. The multiple spurs can also be seen on chicks as young as a day old, with several enlarged scale patterns on the legs (1). It also is believed to slow the overall growth of the spurs, with cockerels having multiple spurs growing in all three later than birds with just a single spur (2).

It is believed to only act on top of the existing recessive spur gene, and can be paired with a suspected henny spur gene that allows the female line to also grow spurs, as seen in Sumatra (6).

This gene was originally discovered in 1941, and was determined to be linked to the duplex comb and polydactyl genes - meaning the locus is particularly close to that of the duplex comb (2). The exact locus and gene that causes this is unknown.

The only APA recognized breeds allowed to have multiple spurs are the Sumatra and Cubalaya (5), though it has also been reported in gamefowl, cemani, and some continental breeds like Dorking.

Breeding with Multiple Spurs:

Multiple Spur x Multiple Spur = 100% Multiple Spurred

Multiple Spur x Single Spur = 100% het. Multiple Spur (Will have three separate spurs)

Multiple Spur x het. MS = 50% Multiple Spur, 50% het. MS (all will have three separate spurs)

Het. MS x het. MS = 25% Multiple Spur, 50% het. MS, 25% Single Spur

Het. MS x Single Spur = 50% het. MS, 50% Single Spur

Multiple Spur x No Spur = 100% Spur Carrier, het. MS.

Multiple Spur x Spur Carrier, het. MS = 50% het. MS, 50% Spur Carrier, het. MS