Concepts of Dexter Color Genetics
page contains the fundamental principles of
the inheritance of color in Dexter cattle. These
principles are stated in the form of ten basic
concepts and are presented in logical sequence.
1. Dexter cattle occur in three
distinct colors: black, red, and dun. Two pairs
of genes that are located on separate chromosomes
control these colors.
2. Black and red is one pair
of alternative colors. In Dexter cattle, there
are two different red genes. The two red genes
are alternatives to each other, and they are
not visually distinguishable. However, they
are distinguishable by a DNA test. Both red
genes are recessive to their black alternative.
This means that every red Dexter contains two
red genes, one inherited from its sire and one
inherited from its dam.
3. Black and dun is another
pair of alternative colors. The dun color in
Dexters is due to a brown mutation, and it is
recessive to its black alternative. This means
that every dun Dexter contains two dun genes,
one inherited from its sire and one inherited
from its dam.
4. Two black Dexters can produce
black, red, or dun calves. In order for two
black parents to produce a red calf, each parent
must carry a hidden red gene. In order for two
black parents to produce a dun calf, each parent
must carry a hidden dun gene.
5. In Dexter cattle red is
the only color that breeds true. Two red Dexters
can produce only red calves even if each parent
carries a hidden dun gene. A Dexter that contains
two red genes and two dun genes is red in appearance.
6. If a red Dexter that has
two dun genes is crossed with a dun Dexter that
does not carry a red gene, the result will be
a dun calf. Each dun calf resulting from this
cross will carry a hidden red gene.
7. Two dun Dexters can produce
dun or red calves. In order for two dun parents
to produce a red calf, each parent must carry
a hidden red gene. Every red calf that is produced
by two dun parents will have two dun genes.
(See #5 and #6 above.)
8. When a red Dexter that doesn’t
carry a dun gene is crossed with a dun Dexter
that doesn’t carry a red gene, the result
will be a black calf. Each black calf resulting
from this cross will carry a hidden red gene
and a hidden dun gene.
9. A colored Dexter calf must be red
if its sire or dam is known not to carry dun.
Conversely, a colored Dexter calf must be dun
if its sire or dam is known not to carry red.
10. Additional genes, independent
of the genes for the basic colors, may be present
in an animal’s genotype and may modify
the appearance of the animal. Such genes include
but are not limited to those which are responsible
for brindling, black noses in reds, black shading
in reds, and the shade of color of reds and
duns. Modifier genes do not alter the principles
contained in the preceding nine concepts.
the color to the right, to view examples of
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American Dexter Cattle Association
1325 W Sunshine #519
Springfield, MO 65807