Inheritance of Red Coat

This bulletin about the inheritance of red coat colour in Speckle Park has been prepared for two reasons.

  1. The CSPA rules of eligibility for the registration of Speckle Park prohibit the registration of red coloured Speckle Park (CSPA By-laws, Section 15, 4c).  SPI (Australia and New Zealand) have the same prohibition.
  2. In light of the previous regulations the unintentional production of red coloured Speckle Park brings a financial loss to the breeders and customers.

Breeders need to understand how the red coat colour is inherited so as to make the best breeding choices for the sake of their financial success and the greatest satisfaction of their customers.  A case in point is the making and selling of embryos.  Customers are not happy when the embryos they bought for domestic use or for export with the accompanying expense of purchase, shipping and implantation produce red ET calves of any pattern.  All the more so since this could have been easily avoided as described below.

 

The Inheritance of the Red Colour

With Speckle Park it is best and easiest to think of the “colour pattern” of any animal has consisting of two parts, namely, a colour and a pattern.  The patterns (speckled, leopard, pointed white and solid) are inherited independently of the colour (black and red). The colours and the patterns are inherited independently of each other from different genes.  The colours are the product of one set of genes and the patterns are the product of another set of genes.   Hence black coloured Speckle Park can occur with any of the four patterns and red coloured Speckle Park also occur as red speckled, red leopard, red pointed white and solid red.  White is not considered a colour but part of the pattern. 

The inheritance of the black colour and the red colour in Speckle Park is the same as in any other breed of cattle that has some black and some red individuals.  Here is the explanation.

  • The genes producing black are dominant to the genes which produce red. When animal receives one black gene and one red gene, the animal will be black because the black gene dominates (masks) the red gene.
  • Every animal has two genes for colour, and receives one of those two from each parent.
  • A black animal will always have at least one black gene.  And if his or her second gene is also black, the animal is said to be “pure for black” or homozygous for black.  He has no red genes to pass on to his calves; all of his calves will be black no matter what colour the mother of the calf is. The black/black bull (pure for black, homozygous black) will never produce a red calf or a red carrier.
  • A black animal will have one black gene and if he or she receives a red gene from one parent, this black animal is heterozygous for black and is “a red carrier.”
  • “Red carriers” only produce red calves if bred to another red carrier or an actual red animal. 
  • A red calf has received a red gene from each of his parents or he wouldn’t be red; a red calf carries no genes for black and will only produce a black if bred to a black.