These comments on the coat colour of Murray Greys were originally posted some time ago on our website but have now been updated following further testing and field observations.
There are two common base coat colours in cattle: BLACK and RED, with black being dominant. For example, mating Angus to Hereford produces black unless the Angus is carrying red genes. These basic coat colours are influenced by additional genes such as:
Pattern genes – Hereford face, Belted, Roan, Brindle, White Spotting. These genes affect the distribution of the base colour.
Diluent genes – Dun, Grey. These genes reduce the amount of the base colour being expressed.
Each of the above genes is located at different sites (loci) and is inherited independently.
Murray Greys come in 3 colours – silver, grey and black. The base body colour of Murray Greys is black which is modified by a diluting grey gene. The diluting gene reduces the amount of pigment in the hair. One grey (or diluent) gene produces a dun or grey colour and two grey genes produce a white or silver colour. Black animals have no grey genes. The lighter coat colour is favoured in hot climates because it reduces heat stress, particularly in feedlots. Even with a silver coat Murray Greys should show a dark skin.
Glenliam Farm Beroleanne X91 and her twin heifers, HR1 D139 a silver and HR1 D138 a grey, resulting from mating a grey cow to a grey bull. The twins could have been silver, grey or black. These were the first calves by Willalooka Arthur.
Animals with two copies of the grey gene (homozygous animals) show a silver coat colour; animals with one copy of the grey gene (heterozygote animals) have a grey coat. Inheritance of the colour is simple Mendelian genetics. When breeding, a silver animal always passes on a single grey gene. A grey animal passes on a grey gene in 50% of sperm (or eggs) and a black animal has no grey genes. The chances of getting any particular colour are as shown in the table below.
It appears that Murray Greys have a similar diluent gene to Charolais but Murray Greys have black base coat colour while Charolais are red. When silver Murray Greys or white Charolais are mated to Angus they produce grey cattle. The base colour of these animals is still black but receiving a single grey (diluent) gene halves the pigment level so that they appear grey. Because some Angus also have recessive red genes some Murray Greys do too.
The following table shows what colours can be expected in your calves if using Murray Grey bulls over different coloured cows. This assumes that there are no recessive red genes.
At Cadfor Murray Greys we previously avoided mating grey to grey because the Murray Grey Society did not register black cattle. Now that blacks are recognised in the stud book we accept what pops out. We have bred some nice black purebred Murray Greys and have found that these are readily accepted by breeders of black cattle as an alternative to Angus. We appreciate that some commercial breeders prefer to keep their herds uniform in colour and have been sticking with black. Murray Greys are widely accepted as being quiet easy care cattle with proven carcase and eating quality and with few calving problems.
The University of Queensland is now able to test for coat colour using Coat Colour Genotyping at the MC1R (melanocortin 1 receptor) gene locus:
Three possible alleles for this gene are dominant black (ED), wildtype (E+) and recessive red (e):
“ED” is dominant and when present in an animal produces black coat colour.
“e” is recessive and two copies will produce red coat colour.
“E+” is neutral, producing a black coat in the presence of “ED”, a red coat in the presence of “e” and a variety of colours in E+/E+ animals, where other genes also influence the pigments produced.
The following combinations are found:
With further advances in DNA technology and testing of our cattle the colour of Murray Greys will be better understood.
Testing of a small number of silver animals has shown that they have no diluent genes. They appear to have a dominant silver gene which imparts a silver colour irrespective of the presence of a diluent gene(s). Individuals with a single copy of this dominant silver gene when mated to black animals produce only silver or black offspring. Where this gene has come from or how long it has been in Murray Greys has yet to be determined.