Colour Genetics for producing a coloured Info please

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Folara

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I was asked today by someone on the yard what the chances would be of getting a coloured from his bay mare.

Now I understand a 'tiny' bit about colour genetics, as in bay being a strong colour but not enough to know what the percentages would be of getting a coloured.

Any help would be great so I can pass the info on.
 
Well, not entirely sure but one of the mares at the yard through a coloured foal and she's dark bay. She was put to a stallion that was 'garanteed' to give coloured foals. I think it depends on the dominance of the coloured gene??
 
Ahhh thanks. Something in the back of my mind was telling me this but I just couldnt put my finger on it and wasnt 100% sure it wasnt just one of those things you 'hear'.

Can let my friend know for sure now.
grin.gif
 
The coloured gene is dominant,so if the stallion is hetrozygous you have a 50% chance of a coloured foal. Studs that quote any other percentage are taking into account the mares input (a certain amount of the mares sent will have been coloured & will have provided their own genetic input). It also needs to be bourne in mind that each sucessful covering has no relation to any other - statisically it is a new event, and each covering will have the same 50% chance as any other.
 
from waht I gather it can depend alot on the stalion you can get a proven stallion that always throws coloured foals, I know of one he's not the prettiest but does have gorgeous babies to TB type mares)
 
Thanks for the help everyone. I have a feeling Sambertino is one of the coloured stallions being looked at and I 'think' he is homozygous tobiano.

Whats the dif. between hetrozygous and homozygous?

Any good books I can get to help with this. I am also considering putting Millie back into foal next year (if all goes well this year) and would love another coloured.

Also if you have:

Sire Dark Bay Dam Bright Bay
Grandsire Bay Grandsire Grey
Grand dam Grey Grand dam Bay

Would you get a Bay?
 
Homozygous have two coloured genes. As the coloured gene is dominant they will get 100% coloured offspring. Hetrozygous have a coloured & a plain gene.They are coloured themselves because the coloured gene is dominant, but if they also have a solid colour (recessive) gene as well. It's 50 /50 which gene actually gets used in the conception.
 
[ QUOTE ]
Also if you have:

Sire Dark Bay Dam Bright Bay
Grandsire Bay Grandsire Grey
Grand dam Grey Grand dam Bay

Would you get a Bay?

[/ QUOTE ] You might get a bay, but it is possible that you might get a chestnut, as the chestnut gene is recessive and so can be 'hidden' and carried on for generations. If both bays carried a hidden chestnut gene then it is possible for those two genes to combine to give you a chestnut foal.

You definitely won't get a grey as grey is a dominant colour, so if a horse carries a grey gene you can see it in the coat colour. As both parents are bay, then a grey is impossible.
 
[ QUOTE ]


Also if you have:

Sire Dark Bay Dam Bright Bay
Grandsire Bay Grandsire Grey
Grand dam Grey Grand dam Bay

Would you get a Bay?

[/ QUOTE ]

As far as I can work out yes you will. As the Grey is dominant both parents must have two 'bay' genes each to be bay themselves. Therefore they can only pass on bay genes. Also the Grey grandparents must have been hetrozygously grey - ie had a grey gene & a bay gene each to have had bay offspring.
 
Yes..I'd forgotton that bit..............there could well be a 'hidden' chesnut recessive - especially as the dam is decribed as 'bright bay'. That could mean the there is a hidden chesnut recessive acting as a 'dilute' on the bay.
 
Thanks guys. Really helpful. Not sure I shall tell my friend she could end up with a chestnut as shes not that keen on them lol. She definately didnt want a grey so thats good news.

I know Millie (my girly) will have a dark bay as both she and the sire (Medoc) are dark bay and only have Bays on either side. Now all I want to make sure is its a colt lol (and alive and well would be good this time - dont think I could go through that again).
 
Oh thats ok. Its me thats used Medoc, not my friend. She has used an ID (cant remember who). I dont mind a nice bright chestnut.

Incidently what was/is your Medoc offspring like?
 
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