Red factor (cattle)
In Holstein Friesian cattle expression of red pigment instead of black colour is caused by an autosomal recessive trait, called red-factor. Black pied Holstein, carrying one copy of this gene, are sought after for breeding to red animals.
Molecular genetic testing of the causative mutation in the MSHR gene allows reliable detection of
red-factor carriers in black pied Holstein which then can be used for introgression intro red coloured lines.
Note: This test detects the mutation MC1R_e (g.14757924delG; UMD3.1). It provides no information of the presence of other possible alleles in individual cattle breeds which may cause red coat colour, as well.