When bred to a heterozygous red mare the possibilities are approximately 50% palomino, 25% buckskin and 25% smoky black.
When bred to a heterozygous bay mare the possibilities are approximately 65% buckskin, 22% smoky black and 13% palomino.
When bred to a heterozygous black mare the possibilities are approximately 88% smoky black and 12% palomino.
Why
can never produce a red colored foal.
Your foal will never be bay when breeding to Whitey's Bar.
THE BASIC COLORS:
AS many of you know, horses come in only 3 basic colors; chestnut, bay and black. That's
it. Any other color is just a variation to these 3 basic colors and are due to contributions of other coat color genes responsible
for adding lighter or darker shades, certain patterns (i.e. dun), or even adding spots and white hair to the horse's coat
color. Other genes responsible for the colors we love so much are cremello, dun, champagne, sooty, mealy, shade, tobiano,
sabino, and overo just to name a few.
SO WHAT IS A CREMELLO?
A cremello is a chestnut lightened twice
because of his 2 copies of the dilution gene "Cr+, Cr+". A perlino is a bay lightened twice due to his 2 copies of the dilution
gene. And a smoky cream is a black lightened twice with 2 copies of the dilution gene. (Although this gene is technically
called the 'cremello' gene, many people know of it as the dilution gene, so I'll refer to it as 'dilution' here forward.)
All these horses are known as "double dilute" horses. One copy of the dilution gene allows for the horses basic color of chestnut
or bay to be lighted to a palomino or buckskin, respectively, and these horses have just one copy of the dilution gene "Cr+,
-". When an animal posesses two copies, their basic color is lightened even further to either a cremello, a perlino, or a
smoky cream. These horses were once thought to be albino horses, however, albinos don't exist in the horse world (refer to
Dr. Ann Bowling, UC Davis)! Ever see a horse with red eyes??? Me neither.
HOW DOES A CREMELLO CREATE A PALOMINO
OR BUCKSKIN?
When cremellos (or any of the double dilutes) are bred to a another horse they will ALWAYS contribute
one copy of the dilution gene! Therefore, the chestnut based foal will be lightened to a palomino and the bay based foal lightened
to a buckskin. But wait, it's not just that simple. Some bays can produce palominos for they may be heterozygous for the black/red
factor. If that mare doesn't pass on that one black factor gene she may pass on a red factor (chestnut) gene and, therefore,
produce a palomino.
CAN A CREMELLO CREATE A LETHAL WHITE?
Nope, not a chance. The color cremello is not
the cause of lethal white foals, only the overo gene is! Cremello is a color and is not an overo expression! In order for
a lethal white foal to be created both parents need to have an overo gene. For example, one of Why's parents needs to have
a genotype positive for the overo lethal white gene for him to possibly pass on the overo gene. Even then, the mare he breeds
with needs to contribute an overo gene as well, to create a lethal white foal . Whitey's Bar is Quarter bred and
does not carry an overo lethal white gene.
WILL A CREMELLO CREATE A FOAL THAT HAS BLUE EYES?
Horses in
Why's pedigree do not have blue eyes. Double diluted horses like Why do have blue eyes due to light skin and eye pigment.
Any offspring from a cross with a solid mare to Why will have brown eyes unless the brood mare is from Paint/Pinto lines,
has lines known for blue eyes, or the foal has excessive white face markings.
THE GENETICS BEHIND IT.
It
is thought that the three basic colors (chestnut, bay, black) are derived from two different loci. A locus (loci for plural)
is an address or a location where two genes live on a chromosome pair. One gene is contributed by the sire and the other by
the dam. Simply put, a loci with its' two genes represent a trait. Loci are located in the same place on the same chromosome
for whatever trait it represents which is why genetic mapping is possible. For the basic coat colors there are two loci responsible
for the 3 basic colors. Sound confusing? It's really not! The first locus to consider is the Extension locus. The Extension
locus holds its' two genes and determines whether the horse will be chestnut or not. The other locus is called the Agouti
locus and its' two genes are responsible for determining whether the horse will be a bay or black. It's real function is to
determine whether the black expressed will be restricted to the points (bay) or if it will be spread uniformly over the entire
horse (black).
DOMINANT, INCOMPLETE DOMINANCE, AND RECESSIVE GENES
There can be many types of genes that
exist in a particular trait's gene pool. An allele is just another name for those individual genes. An allele may be dominant,
recessive, masked, or incompletely dominant. In coat color genetics, when dominant genes are present they are usually visible
to us (except in the case of solid red horses) and are given precedence over recessive genes. Generally, they are responsible
for the phenotype (the outward appearance) of the coat color trait considered. The incomplete dominance phenonenom is what
you see every time you look at a palomino or buckskin. Since palomino/buckskin horses have only one copy of the dominant dilution
gene their coats are lightened to gold. Two copies cause a doubled effect of lightening and creates a cream colored horse
like our beloved smokey cream, Why! So with incomplete dominance, one dominant dilution gene (Cr+, - ) causes some lightening
while two (Cr+,Cr+) causes even more! Easy enough, right? When the parents create their single celled gamates (the egg and
the sperm), the cells with their full sets of chromosomes divide in half. Those two alleles living at that color locus split
off singularly into separate gamates . In the case of Why, one dominant dilution gene is donated to 50% of the gamates (sperm),
as well as, the other 50% of the gamates (sperm). He will ALWAYS give one dilution gene which is what's needed to make a palomino, buckskin
or smokey black foal.
TRYING TO GET THAT PALOMINO OR BUCKSKIN?
Breeding a chestnut or bay to a palomino
or buckskin stallion will only lend to a 50% chance of getting that dilute color. Why? Those stallions only have one copy
of the dilute gene present on the dilute locus, the other gene is a recessive, nondiluting gene. When the sperm is created
by those studs only half of the sperm will receive that dilute gene. The other half will have a recessive gene that doesn't
create palominos or buckskins. These stallions will have a foal crop of theoretically 50% dilute foals.
GENERAL
COAT COLOR
Luckily, with horse coat color, the alleles act more like on and off switches for each coat trait considered.
If a dominant allele is present, it generally gets to determine whether the trait for that loci will exist or not. With the
basic coat colors (chestnut, bay, black), the extension locus is the first locus mother nature considers. Its' function is
to determine whether the horse will be chestnut or not. Its' genes act like an on/off switch. It can hold either a pair of
"ee", "Ee", or "EE" genes with "e" being a recessive gene (red factor gene) and "E" being a dominant gene (black factor gene).
ALL CHESTNUTS have a pair of recessive "ee" genes ONLY and these genes are located at the Extension locus. If the Extension
locus has the "Ee" or "EE" pair, the Extension locus has, in a sense, switched off the chestnut color due to the dominant
"E" present there. The recessive "e" which is found in the "Ee" situation has no say in the matter and the dominant "E" overrides
its presence. Say good-bye to the solid chestnut color! So then what takes over? The dominant "E" says black is going to exist
but in what form - as a bay (restricted to points) or black (spread over entire body)? To determine that, mother nature next
looks at the Agouti gene to determine whether the foal will be bay or black. The Agouti gene pairs possible are "aa", "Aa",
or "AA". The "a" is the recessive form resulting in black and "A" is dominant form resulting in bay. If the combination of
"Aa" or "AA" are present, then the foal will be a bay. An "aa" pair at the Agouti locus will result in a solid black foal.
As of mid April 03, Davis University in California offers the Agouti test to determine what resides at the Agouti locus. What
can make color genetics so confusing is the Agouti genes are not reflected in the horses coat color when the horse is a solid
red. When "ee" (solid red) exists at the Extension locus then an 'epistatic' gene situation occurs and the Agouti genes are
not considered in the overall phenotype. This can lead to surprise foal colors when breeding your red mares to stallions with
"Ee" or "EE" genotypes (therefore allowing the Agouti genes to be expressed).
THE RED FACTOR TEST
U.C.
Davis and several other companies offer a test called the red factor test. This is a DNA test to see what genes are present
at the EXTENSION locus. If the results come back as "ee" then the horse is said to be homozygous for the red factor. It is
generally understood that if your horse is a red color with no black points that she is "ee". Don't even waste your money
for the test! If results come back as "Ee" then it is said that the horse is heterozygous for the red factor or another way
it has been put is 'the horse is heterozygous for the black factor.' The "E" is the black factor. If the results are "EE"
then the horse is said to have no red factor or is said to be homozygous for the black factor. The "EE" horse will not be
able to throw a chestnut baby ever because he/she will never be able to pass on a recessive "e" at the Extension locus for
he/she doesn't have one to contribute. Only the "E" will be passed on. It takes two "e"s genes to make a solid red foal -
one from the mom and the other from the dad. The "Ee" or "EE" pairs just means that the Extension locus is now shut off to
creating a solid chestnut and, now, whatever genes exist at the Agouti locus can now be expressed. This can be "aa" (black),
"Aa" (bay - heterozygous), or "AA" (bay = homozygous). It is also generally understood that if your horse is a true black
that she is "aa" at the Agouti locus. Many black looking horses are truly very dark bays and have the genotype of "AA" or
"Aa". With the new Agouti test offered at Davis University, horse owners no longer have to study their horses parentage to
get a better idea of what exists there. Red factor and Agouti test information can be found at the UC Davis site http://www.vgl.ucdavis.edu/horse/hrseinfo.htm
THE BLACK FOAL.
Breeding a solid red mare to a cremello will never result in a black foal. The resulting
foal will always be a palomino. Always! ON rare occasions with many cremellos, if the mare is bay "Aa", a black foal could
result called a smoky black which range from brown to black in color. The same exact phenonenom and odds happen when breeding
a bay to any red based color stallion (chestnut, sorrel, palomino or cremello). How can this be? Both the stallion and the
mare have to have a recessive "a" at the Agouti loci and both have to contribute it to the foal; "aa" = black. If your mare
comes from a long line of bays the chances are fairly slim that she will ever produce a black. The same is true for the stallion,
if the stallion shows a long line of non-blacks then his odds of being responsible for a black are very slim. If one of the
parents have a dominant homozygous genotype "AA" at their Agouti locus then a black foal will never result no matter what
color the other parent is, even if the other parent is a black horse! But don't just breed for color, Why's pedigree is loaded
with champions and champion producers!
CREMELLO / PERLINO FOALS
Breeding a palomino or buckskin to another
palomino or buckskin lends a 25% chance of getting a cremello or perlino foal, 50% chance of a palomino or buckskin, and 25%
of getting a bay or chestnut foal. When breeding a palomino or buckskin to a cremello, the outcome ratio is this: 50% palomino/buckskin
and 50% cremello or perlino. Either cross creates a 50% chance of getting a palomino/buckskin. Seems odd, doesn't it? But
true. (This is not considering slim chances of 'aa' smokey blacks.)
GRAY FOALS
Gray foals are the product
of one or both parents being gray or soon to turn gray. Dreamer will not produce any grays unless bred to a gray mare. In
this case, the outcome of the foal becoming gray should be 50%. These foals will have a dilute coat that will eventually turn
gray!
GENETIC BOOKS, WEBSITES!
If you're interested in learning more about genetics, Dr. Sponenberg wrote
"Equine Color Genetics" which is a fabulous book and can be found at
www.conquistador.com/colgenetics.html.