F E AT U R E
I
n a rainbow world of colours, coat
Colour genetics 101
patterns and markings, the palette your brand-new foal could draw
from is seemingly endless. But there is a science behind all this wonderful potential, and today you get to put on your white lab coat and learn all about coat colour genetics. Not surprisingly, genes are passed from
Ever wondered why your horse is the colour that they are? In the first of a two-part series, CHRISTINE ARMISHAW dives deep into the wide and wonderful world of coat colour.
the mare and stallion to the foal. The resulting colour of the foal is determined by which genes they receive, as well as by how many of each. You can’t tell by looking at a horse what its colour genetics are, you need to test for them. Kao Castle B.Sc.(Hons.)(Advanced) PhD, the driving force behind Practical Horse Genetics, has combined her love of chemistry and horses, culminating in her dream career in horse genetics, and a job in which people send her gorgeous foal photos on the daily. A benefit of tapping into the hidden world of horse genetics is that breeders can use DNA testing to help predict what colours their foals might be, and even whether there is any potential to produce a colour pattern that can have adverse health issues. One common colour-related factor is the lethal white gene. Linked to the frame overo colour, it results in the death of an affected foal. I asked Kao how many potential horse colour genes we could be dealing with. She pauses, laughs, and simply says “a lot!” But when we start to break it down to make sense of it all, the number of base colours we’re working with is much less, essentially consisting of chestnut, black and bay/brown. Unfortunately, genetics at this point can’t tell the difference between the various shades of bay and brown. They’re all just grouped together as one big category,
The classic black horse has a black body, black mane, tail and points (Image courtesy Crown K Quarter Horse Stud, photographer Francene Neuendorf).
no matter whether you’ve got the brightest red bay, or a brown that’s so dark it’s almost black. This got the cogs in my mind turning: what about grey? Turns out, grey is not
