AUSTRALIAN LIMOUSIN BREEDERS SINGLE GENES

Predicting the Outcome

Sometimes the outcome of a mating can be predicted with complete accuracy. For example a homozygote horned bull (pp) over a homozygote horned cow (pp) will produce 100% homozygote horned progeny (pp).

In other cases we can only predict the probability of the outcome.

For example, a heterozygote polled bull (Pp) crossed with homozygote horned cows (pp) will produce 50% polled progeny (Pp) and 50% horned progeny (pp).

Colour

The same principles as described above apply for the red and black colour with black being dominant and red being recessive.

Red is a recessive gene, so animals that are red are most likely to have homozygous (double) red genes.

Several genes are involved in the process of creating the complex coat colours and patterns found in cattle. The three alleles of this gene are dominant black (ED), wild type (E+) and recessive red (e).

Dominant black (ED) is dominant to the other two alleles and animals with this allele are jet black (solid or spotted). The wild type (E+) produces cattle with reddish brown to brownish black coloration with a tan muzzle ring. Two copies of the recessive red (e) allele will result in red colour.