IN THE PREVIOUS ARTICLE we looked at the basic colours and their method of inheritance. You need to remember that there are only two basic colours, bay and chestnut with bay being dominant over chestnut. If two bays are mated (assuming they are both carrying chestnut) you will get 75% bay and 25% chestnut foals. If two chestnuts are mated the resulting foals will be 100% chestnut and chestnut mated to bay will result in 50% bay and 50% chestnut foals (refer Spring 2010 Action).
CREAM DILUTION is a dominant gene ie you only need one copy for it to be expressed. It is not lethal when homozygous. A
single cream dilution gene does not affect black pigment which is why a true black carrying a cream dilution gene will still look
black and why the black points, mane and tail on a buckskin (dilute bay) remain black. It does not skip generations.
The Cream Dilution gene is not the Dun gene. For many years buckskins were registered as dun. Dun is commonly found in Quarter Horses, Highland Ponies, Fjords and occasionally Shetlands. ”. Although we don’t seem to have any true duns in our Australian Welsh ponies, they do exist in the UK and other countries.
The body colour is ‘flat’, there is a very prominent dorsal stripe extending into the mane and tail, usually horizontal leg barring, ear tips which cover the top half of the ear and a darker face mask. Any horse can exhibit these primitive markings but in general they will not be as pronounced as in the true dun. Dun can be homozygous. http://www.duncentralstation.com/
Dun Highland pony showing the strong dorsal stripe running down into the tail.
You can see the facial masking over the eyes. Photo: Chris Milvain.
Chestnut + 1 cream dilution gene is a palomino of varying shades depending on the chestnut base colour (dark liver chestnut
+ 1 cream dilution can result in a foal which is almost black with a light mane and tail)
Bay or Brown + 1 cream dilution gene is a buckskin of varying shades which depends on how dark the base colour is.
Black + 1 cream dilution gene is a ‘smokey black’ also called ‘dilute black’ (previously called black buckskin). These look
black. Those that look ‘off black’ are cream dilution working on a fading black or very dark brown coat.
Chestnut + 2 cream dilution genes is a cremello (cream coat, pink skin, blue eyes).
Perlino - cream coat, points like milky coffee. Photo: Lorelle Mercer.
Bay or Brown or Black + 2 cream dilution genes is a perlino (cream coat, pink skin, blue eyes and often coffee coloured mane,
tail and points)
Chestnut x Chestnut results in 100% Chestnut foals
Chestnut x Palomino = 50% Chestnut & 50% Palomino (all the foals are basically chestnut but 50% will inherit the cream dilution
from the palomino parent and those will be palomino).
Palomino x Palomino = 50% Palomino, 25% Cremello, 25% Chestnut (all the foals are basically chestnut, 50% will inherit a
cream dilution from one or other parent and those will be palomino, 25% will inherit a cream dilution from both parents
and these will be cremello, 25% won’t inherit a cream dilution and these are chestnut). The chestnut foals are no longer carrying any cream dilution and cannot produce a palomino foal unless mated to a dilute horse. They have no more chance of
producing a palomino that a chestnut with two chestnut parents.
Palomino. Photo Lorelle Mercer
Chestnut x Buckskin – this is basically chestnut x bay which gives 50% bay and 50% chestnut. The cream dilution has 50%
chance of being thrown so the resulting foals will be 25% bay, 25% buckskin (bay + dilution), 25% chestnut, 25% palomino.
Bay x Buckskin – this is basically 75% bay and 25% chestnut. The cream dilution has 50% chance of being thrown so the foals
will be 37 ½% bay, 37 ½% buckskin, 12 ½% chestnut, 12 ½% palomino.
Chestnut x Cremello – as cremello is chestnut with 2 cream dilutions and chestnut x chestnut results in 100% chestnut foals the
base colour is chestnut. As cremello has two cream dilution genes it must throw one so all the resulting ‘chestnut’ foals will
be palomino (chestnut + cream dilution)
Buckskin Mare with dilute black foal. Photo Lorelle Mercer
Palomino and Buckskin can be masked by Grey. If the palomino or buckskin has greyed out it will still breed the same as a non-grey palomino or buckskin and then at least ½ the foals will grey out. This is why two greys can sometimes produce a cremello, both were born palomino and/or buckskin. These cremellos have 75% chance of carrying the grey gene. Palomino and Buckskin can be masked by Roan. Roan can be very hard to distinguish in a palomino or buckskin (see Spring 2010 Action) but half the foals may be roan.
Chestnut + one or two dun genes will result in a Red Dun (chestnut body coat with pronounced dun factor markings).
Bay + one or two dun genes will result in a normal Dun (bayish body coat with pronounced dun factor markings).
Black + one or two dun genes will result in a Grulla (pale blackish-mauve body coat with pronounced dun factor markings).
Dilute Black - Photo Coady Photographics.
Chestnut + one or two dun + one cream dilution gene will result in a Claybank (palomino dun), flat palomino body coat with pronounced dun factor markings.
Buckskin foal - the legs will darken as the foal coat sheds. Photo: Lorelle Mercer