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From: sbishop@desire.wright.edu
Newsgroups: sci.bio
Subject: Re: A Genetics Question
Message-ID: <1991Jan31.194553.2400@desire.wright.edu>
Date: 1 Feb 91 00:45:53 GMT
References: <480sis-b@massey.ac.nz>
Organization: University Computing Services, Wright State University
Lines: 49

In article <480sis-b@massey.ac.nz>, S.Burger@massey.ac.nz (Sarah Burger) writes:
> I was wondering whether anyone could determine the probable colour
> of a foal. The sire is a bay - his sire is a bay, dam is a chestnut.
> The dam is a palomino - her sire is a palomino, dam is a chestnut.
> 
> Any guesses as to what colour this ( as yet theoretical ) foal might be?
> 
> Thanks in advance,
> Sarah Burger
> School of Information Sciences
> Massey University
> New Zealand

Actually, a palomino is just a pale chestnut.  In fact, some breeds don't
recognize palomino as a color.  (Never say palomino to an Arabian owner,
we call them 'bright chestnuts')  Bay is a dominant, chestnut is recessive.
To get chestnut the foal needs to inherit one gene for the color from EACH
parent.  To get Bay the foal only needs to inherit one gene for the color
from one parent, the other gene would be chestnut.  Since the sire is bay
but he must carry recessive chestnut, he would give one chance in two of
passing on the bay gene.  Since the dam is palomino, she carries two genes
for chestnut, one pale and one normal.  So, you have two chances in four
of getting a bay, one chance to get a regular chestnut and one to get
a palomino.  I've simplified this a little but this is your chances.
It's really a little more complicated than this; I think that there is 
another gene involved that causes the paleness of the palomino.  I do know
that if you breed a palomino to a palomino you usually get a cremora (very
pale almost white, NOT acceptable in palomino circles.)
BTW, I bred my grey mare to a bay stallion and got a chestnut...  The mare
was recessive chestnut and so was the stallion.   I had one chance in eight
of getting a chestnut.  (Grey is dominant and so is bay)

I'm breeding my chestnut this year but quite by coincidence the stallion is
also a chestnut so I know what color I am getting.  Well, not actually by
coincidence, they have some bloodlines in common.  Anyway, color is not a 
factor in this breeding, I'm going for strengthening of the particular 
bloodlines and, hopefully, an future show horse.  (The bloodlines are
noted for looks, personality and performance.) 

	B   	c
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       |    |     |
    c  | Bc | cc  |
       |    |     |
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       |    |     |
    p  | Bp | cp  |
       |    |     |
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