UNDERSTANDING: BOVINE COAT COLORS
According to North Carolina State University, most of the cattle possessed one of the three basic colors - red, black or white. There are about 6 color combinations for Bovine coat colors as a result from genes of the two animals. There has been some practice in cattle raising that coat colors are related to the meat value and performance of the animal. This is a wrong perception. However, understanding the coat color and the color pattern is valuable in marketing the animal.
What does coat color represent?
B.C Allison stated that bovine coat color is not an indication of the animal’s breed for mixed breed cattle. The animal's genetic makeup is responsible for both its qualitative and quantitative traits. Breeding for its coat color - a qualitative trait - requires a few genes to be paired. But breeding for performance requires a number of paired colors. This is the reason why breeding for color is easier for breeders rather than breeding for growth and performance.
Coat color classification
The registries of animal color classes were the result of the breeder’s perception and observation. Most of them were not done by genotype testing but rather phenotypical. What appears to be Red by just looking at the animal may have a different result once genotype testing is done. This is the reason why some animals were registered under three colors: Black, Red, and Dun.
Black dominates over red. Hence, the coat color is determined by a pair of genes. Homozygous means that both color genes are the same. While Heterozygous means that each of the two-color genes is different.
The Melanocortin 1 Receptor (MC1R) gene, also called Extension, is responsible for the coat red and black. It is responsible for the production of black (eumelanin) and red (phaeomelanin) pigments.
According to Miniature Cattle’s site, The MC1R [DNA] test presents 3 common alleles of the MC1R gene that affect the coat color of bovine where the color Black (ED) has shown dominance. The Wild type (E+) takes the second spot on color dominance. It produces bovine with coat coloration somewhere reddish to brownish.
Coat colors: six possible genetic combinations
The gene for black is dominant to the gene for red; therefore, bovine with one gene for black and one gene for red (heterozygous) will be black. There is an incomplete dominance between the gene for black and the gene for white, resulting in bovine with one gene for black and one gene for white being a black-roan color. There is also an incomplete dominance between the gene for red and the gene for white, resulting in bovine with one gene for red and one gene for white, being a red-roan color. The gene for white is recessive, resulting in only bovine with two white genes (homozygous) being a true white color. A more specific table is presented below for the coat variation according to the genes of the bull & the cow.
Type of Genes Affecting The Cattle’s Coat
This was based on the article by Alan Bias of Galloway Cattle Genetic Discussion Group.
BLACK: The black allele is abbreviated (ED).
The subscript D stands for dominant black. An animal with (ED) present is always black. The (ED) allele is dominant to (E+) and (e). The accepted order of dominance is ED > E+ > e. Cattle that are (e/e) are the recessive red genotype.
WILDTYPE: The wild-type allele is abbreviated (E+).
The superscript + symbol is used to designate a wildtype allele. Initial color coat testing done on Wild-Type Reds during the 1990s by GenMARK concluded at the time these animals were heterozygous black (Bb). Wild-Type Red animals often have deep burgundy red bodies. The extremities (head, neck, feet) appear to be darker or black from a distance. But when viewed up close or in natural sunlight the red coloration is visible down to the root.
Wildtype alleles produce both eumelanin and phaeomelanin through intermediate amounts of tyrosinase. The ratio and distribution of these two pigments may be modified by other genes. The visible expression of eumelanin seems sex linked. This can be observed in wild-type (E+) bulls, which express a darker head, neck and feet as compared to females.
Heterozygous (E+/ED) are most often dark black in color, since even one copy of ED will produce an over-abundance of eumelanin. In heterozygous (E+/ee) variability of coloring in these animals is expected, and poorly documented.
RED: The red allele is abbreviated (e).
Lowercase is used to indicate that the allele is recessive to the other two alleles for color (ED) & (E+).
This bull & cow will produce these calves based on this probability:
ED = Black; E+ = Wild type red; e =True red
ED/ED = homozygous black
ED/E+ or ED/e = heterozygous black, red carrier
E+/E+ = homozygous wild type red
E+/e = heterozygous wild type red
e/e = homozygous true red (true red and wild type red act as the same when bred with black
Both parents homozygous black
ED/ED x ED/ED
ED/ED
100% homozygous black calves
Both parents heterozygous black
ED/E+ or ED/e x ED/E+ or ED/e
ED/ED
ED/E+ or ED/e
E+/E+ or E+/e or e/e
25% chance calves will be homozygous black
50% chance claves will be heterozygous black, red carrier
25% chance calves will be red
One parent homozygous black ED/ED
One parent heterozygous black ED/E+ or ED/e
ED/ED
ED/E+ or ED/e
50% chance calves will be homozygous black
50% chance calves will be heterozygous black, red carrier
One parent homozygous black ED/ED
One parent heterozygous red E+/E+ or e/e
ED/E+ or ED/e
100% heterozygous black, red gene carrier
One parent homozygous black ED/ED
One parent heterozygous red E+/e
ED/E+ or ED/e
100% heterozygous black, red gene carrier
Both parents red
E+/E+ or E+/e or e/e
E+/E+ or E+/e or e/e
100% red
Source: Miniature Cattle
