MAHOGANY COAT COLOUR CHANGES
This is one of the most interesting colours
that we have seen in Highland cattle across the world. It came into Australia in
a Canadian cow - Anne of Glen Aspen (Can 4463). One of her embryo
calves was Molly of Dandaloo (1429), who was one of
the matriarchs of our herd. While they are born a rich red colour, this slowly
changes during their life in a most dramatic way.
The
calves are born a rich red colour, somewhat darker than those of the normal red
colour, but could be easily missed if
you
didn't have a red one standing beside it. The outer coat
slowly changes over the ensuing months and starts to lighten off. Interestingly
the longer the coat, the lighter this outer coat becomes (see that the five
month old bull calf on the right has white on his near side front leg as the
wind blows it open).
By the time the calves are weaned, they have
varying amounts of white outer coat on them, yet you can still
see the deep red, mahogany undercoat around the face and elsewhere depending on
the amount of white. This is about their most dramatic and contrasting
stage.
As they progress from here the white outer
coat begins to fall out but they are left with white on their dossan,
topline and tip of tail - this gives rise to the term 'white tips' that a
number
of people have used to describe them at this age. This stage normally lasts
until they are around 18-24 months and will vary in its
expression depending on the time of year (and therefore
the amount of outer coat retained) and there coat length as determined by their
genetics.
Amazingly, with age, the
white tips slowly fade and the mature animal is left
with a white tip to their
tail and maybe some white on their dossan. They still
have quite a distinct and different colour to their undercoat however.
At this stage, especially through summer when the coat is
shorter, you can see that some of these animals will possess the brindle gene as
well. The black stripes will be most obvious on their
sides and around their eyes.
While this is a truly remarkable colour pattern, the
genetics behind it appears to be quite simple. That we can establish, it appears
to be a single dominant gene. This means that an animal with one gene for this
coat
colouring will produce the mahogany
colour on average in every second calf that they have. It also appears impossible to reproduce from cattle where neither
parent has this colouring. We have also never seen it associated with dilution
colours (yellow or duns), although a number of other animals we have seen can
have lighter shades on their dossans and tails.