grey mare x homozygous stallion

[Magicmadge]

My grey (now white) mare is in foal to a coloured homozygous stallion. I find genetics very confusing, if my mare is by two grey parents does that mean she is homozygous for grey, if so what will my foal be from two homozygous parents? Some links on the net say the colour will fade out to give me a blue and white anyone with any ideas?

 

[JanetGeorge]

You have a 100% chance of a coloured foal. You have a 50% chance it will grey out UNLESS your mare is homozygous for grey. Two grey parents means she MIGHT be homozygous for grey - but not necessarily so!

 

[SirenaXVI]

As Janet has said, if the stallion is homozygous (2 coloured genes) you are 100% certain to get a coloured foal BUT as grey is not a colour as such (it is an effect on a colour) you still have a 50% chance of that foal greying out, yes you would end up with a blue and white coloured but it would only be a stage in the greying process and would eventually turn white/grey. If your mare is homozygous (2 grey genes) it is 100% certain the foal will grey out. If both her parents were grey there is a very very strong chance that she is homozygous, however, it is possible, but unusual, for 2 grey parents to have a non greying foal if both are heterozygous for grey so it is also possible for two heterozygous grey parents to have a heterozygous foal.

There is no current test for the grey gene unfortunately, so you will just have to wait and see!

 

[xspiralx]

Well to be specific, if your mare's parents were both hetero [Gg] for grey, then there is a 25% chance of producing a homozygous grey foal - 50% that it will be heterozygous grey - 25% chance that the foal will not be grey. Unless either of your mare's parents was homozygous themself, in which case there would be a 50% chance of a homozygous grey foal, 50% chance of a hetero grey.

Anyway, as has been said, if your mare is heterozygous for grey then there is a 50% chance that the foal will grey out, but if she is homozygous then the foal will definitely inherit grey. It will definitely be a coloured but would eventually turn completely grey if it inherited the grey gene.

 

[Marengo]

Actually there is now a new test for the gray gene. http://animalgenetics.us/Equine.htm

The test is both to see if you have a grey foal/horse that isn't showing signs of gray yet and to determine whether the horse is heterozygous or homozygous (one copy or two copies of the gray gene).

You could test your mare if you're interested but it might be more efficient to test the foal. If the foal doesn't get the gray gene you'll know she's heterozygous.

 

[JanetGeorge]

[ QUOTE ]
If both her parents were grey there is a very very strong chance that she is homozygous,


[/ QUOTE ]

Not THAT strong. I had two grey fillies foal this year - both are by my grey stallion (who is definitely heterozygous) - one out of a mare I know is heterozygous as she's HAD a bay foal (to my grey stallion), and the other out of a mare who has always had grey foals to my grey stallion (5 to date). Both fillies went to a dark brown stallion and both have produced dark brown foals with no sign of greying.

 

[burtie]

[ QUOTE ]
If both her parents were grey there is a very very strong chance that she is homozygous

[/ QUOTE ]

If both parents were heterozygous then a 25% chance, if one parent was homozygous then a 50% and if both parents were homozygous then a 100% of your mare being homozygous, simple isn't it!

 

[Sambertino]

The Grey test is also done in the UK now & is only £16, so probably worth doing on your mare to see if she is homozygous?

http://www.horsedna.co.uk/