Scared of the colour determined through breeding of horses
The choice of the right stallion for the ongoing season has either already been met or is to be made in the near future.
We excitedly await the birth of our foals in this year and more than a few of us have chosen the stallion due to his colour and our desire to get a particular colour from a particular mare.
It is often not necessary to be frightened of getting a grey – most of the time where we dubiously hope not to get a grey – the chances were relatively slim and would not have influenced the end product of a specific mare. Had we only researched into the "rules" of colour determination a little further before making our decision which stallion would produce which colour we could have slept more peacefully up to the time of the birth!
"In this black or chestnut stallion, too much grey blood can be traced, and this could come through with this pairing" How often have you heard this or a similar phrase and that from an experienced breeder although more proof cannot be found for someone's idiocy than in this expression?
A foal can only be grey when at least one of the parents is itself a grey. Exactly the opposite also applies, from parents who are both not grey – can a grey foal never be born from this pair regardless of how many grey ponies/horses may be found in the pedigree.
To verify this theory or point one must learn the genetic basics concerned. To bring a little light into this otherwise dark subject please read the following details that I have written to explain:
One needs to know firstly that every characteristic of every living thing and so of course is the colour of a horse or pony from two corresponding (homolog) genes predetermined. These two genes can either be the same (homozygote) or different (heterozygote). When referring to homozygote genes one implies pure and when referring to heterozygote one implies a mixed hereditary factor.
With horses there are only two basic colours these are:
black and red = chestnut, although at this point it is important to note that the black factor dominates over the red factor (chestnut). The following can be concluded from these facts:
A black horse can either be of a pure hereditary nature or a mixed hereditary nature to have become black. Externally seen, both horses are black, the different make up of the factors that produced the black colour are invisible.
A chestnut is however always of a pure hereditary nature, if the horse should carry a black gene, it wouldn't be a chestnut, it would be black as the red/ chestnut factor is weak in relation to the black factor.
With the pairing of two horses there are the following possibilities, named the "Punnet Squares", named after a British biologist Punnet.
The following keys have been chosen to illustrate the theory:
♂? = Stallion
♀? = Mare
B = dominant black factor
c = recessive chestnut factor
A) The pairing of two black horses with parents on both sides black
Would give a100 % chance, to become a black horse.
B). The pairing of two chestnuts:
Would give a 100 % chance to become a chestnut.
C) The pairing of a pure black with a chestnut:
This would give 100 % a mixed hereditary black horse.
All offspring would be black.
D) The pairing of two mixed hereditary blacks:
This would give 25 % pure hereditary black,
50 % mixed hereditary black and 25 % chestnut.
E) The pairing of a mixed hereditary black with a chestnut:
This would give 50 % mixed hereditary black and 50% chestnut.
So much to the genetic laws of the two basic colours black and red= chestnut.
Apart from these two basic colours there are other changeable factors such as:
the brown factor
the grey factor
the roan factor
the thinning factor
the checked factor and many others:
These factors influence the basic colours in different ways.
To keep things simple we illustrate here the first named changing factors. Should anyone want to delve more deeply into the genetics and their influences in the characteristics of horses etc. they must busy themselves with a barrage of factual literature available.
The brown factor:
The brown factor can be seen by black horses (both pure hereditary and mixed hereditary blacks) in that the black pigment of the hair (the exception being the mane and tail colour and bottom part of the legs) is put back and changed into a more or less light brown tone
The brown factor is therefore proved to be dominant over the black factor.
A horse that is seen to be black externally, can never carry a brown factor. Should one couple two blacks with one another a brown foal can never be produced (however on average
25 % - a chestnut, when both blacks are of a mixed hereditary, see above under D).
If one should couple a chestnut, that carries a brown factor with a pure hereditary black, 50% of the offspring would be brown, if the chestnut in relation to the brown factor of mixed origin should be coupled with a pure hereditary black there cannot be a black from this pair produced.
All offspring from such a combination would be born brown.
The grey factor:
For breeding purposes it is easier to calculate the grey factor as the brown factor:
The hereditary factor for grey overshadows all other colour factors, i.e. a horse or pony that carries this factor will become whiter with age irrespective of whether the grey comes from a pure hereditary factor or a mixed hereditary factor.
If a grey is of a pure hereditary nature than all of his offspring will be, without exception, grey.
Should a grey with a mixed hereditary factor be coupled with a black, a brown, a chestnut, or a palomino the offspring would be about 50%. The other 50% remain the colour that is predetermined in their genes (see above Letters A-E). And because the grey element is such a "radical-dominant" factor, when two greys are coupled – a grey cannot be reproduced, irrespective in which generation and how often a grey can be found in the family tree! The worries from breeders who think that a grey element somewhere along the lines can at a later time reoccur are not founded.
In conclusion I would like to add that in the world of breeding with Welsh A and B ponies there is nothing more stunning than a "white God or Goddess" in the form of a good pony on the field!
We have always paired 2 grey ponies together again and again in the hope that a grey foal will be born, up till now without success! That's why we chose in 2003 the grey stallion Shamrock Mr Oliver for our grey brood mare Hondsrug Briall. From both sides we knew that both ponies had a mixed grey hereditary factor. The son born in 2004 Equus Mr Spock is an remains although both parents were grey, chestnut and should we couple him later with a mare that isn't grey, there would be no chance that a grey would be reproduced, as long as one holds these golden rules in mind!