While there are six registrable Highland colours in the Australian Herdbook (see 'Highland Colour Basics'), there are a few genetic colour patterns that do not fit into these categories. These are probably just testimony to the broad genetic diversity that the breed began from many centuries ago. This adds to the interest in breeding these wonderful animals, but also adds to the genetic complexity when trying to understand how it all works.
We have bred quite a number of these animals and have chosen to name this colour mahogany. It is a dark red colour but has always appeared with white tips, especially on the dossan, tip of tail and variable amounts along the topline and mane. These are very interesting calves to watch over their first 12 months of life (Mahogany Coat Colour Changes) but the colouring becomes less dramatic with age.
Highlands also have a gene for a ring of short, black hairs around the nose called Bus Dubh (literally meaning 'black muzzle ring'). It is seen more often in females (maybe because we all have more cows in our paddocks than bulls) and only ever in red animals. Some feel it is in some way associated with the brindle gene. It can vary in intensity from year to year, season to season in animals that show this trait. It appears to be generally favoured amongst Highland breeders because it is thought to be a link to the breed's heritage, as few if any other breeds have this characteristic.
This is a rare colour pattern that comes up now and then in Highlands. It is defined as any solid colour with white patches. To date I have only heard of it in red or yellow animals. It is quite rare and not a registrable colour in Australia, but a motion was passed in 1990 in the UK to allow these animals to enter their herdbook.
In Una Cochrane's book, 'A Keen Eye', she researched the pedigrees of a number of parti coloured animals born in the 1990's. She found that these animals all had two common ancestors - a bull, Sgaithanach, and a cow, Rosie, who lived c1870. In every pedigree except for one, both the sire's and dam's side had one of these animals in them. This tends to suggest a simple recessive mode of inheritance - it can appear out of the blue in any ones herd.
(Photos from ' A Keen Eye', by Una Flora Cochrane.)
This is a common gene amongst Highland cattle. It is difficult to visualise in some animals because it can be strictly confined to the udder in some, yet in others will extend well forward. It is accepted in the breed providing the white skin/hair does not reach further forward than the navel. Also, the larger the udder, the more prominent it will appear (see above photos). The mode of inheritance is unproven at the moment, but the gene has quite a high frequency in Highlands. It is probably at the same gene locus as the parti colour allele.