[clydesdaleclopper]

My knowledge of colour genetics is limited to chickens so maybe one of you will know. We have finally finished lambing    and everyone had twins  . My ewes are either Gotland or Gotland x Shetland and are all shades of grey. My tup is Gotland x Shetland and is a pale grey. The lambs are a real mixture of colours though. We have quite a few black ones - which is what I expected as I expect them to go grey as they age. However, we also have a pure white one, a couple that are cream with caramel coloured legs, one that looks like a bit like a dalmation and one that looks like black with a dusting of cocoa powder. Any ideas how the colour works in sheep? I know that blue/grey in the chickens is a dilution of the black gene so the brown has really taken me by surprise.

[kanisha]

It sounds as if you have a white spotting gene in there which is a recessive and expressed on a very limited basis in Gotlands but can be quite extensive in shetlands.

Think of a dalmatian dog - is it a white dog with black spots or a black dog with a very large white spot leaving just little bits of black showing?
The pure white one would have extensive white spotting covering up the grey underneath

the others depending on the birth coats could be a number of mixed patterns from the shetlands combines with the grey from the gotland ( co-dominant agouti patterns) if you have photos i might be able to tell you more.

[clydesdaleclopper]

Wow thanks. I'll try to get some photos when it isn't raining as my camera isn't very robust 

[kanisha]

Oh should have said you've also have the possiblity of moorit as a base colour too.

[jaykay]

In Shetlands, white is dominant and 'covers' all other colours.

The black with the cocoa powder sounds like a Shetland 'warm black'. They go quite chocolate coloured on the outside but have black legs and face, and are black when sheared.

I don't know how the Gotland genetics will get involved but in Shetlands:

There are three 'places' for coat colour genes, each place has two copies, one from the tup, one from the ewe.
Place 1: contains the genes for katmoget, gulmoget, the various greys, and white - which is dominant over everything, then katmoget/gulmoget patterns, then some of the other greys.
Place 2: contains either black or brown. Black is dominant (but white in place 1 would 'cover' this and result in a white sheep). Anything else in place 1 and the black or brown kicks in, ie if it's a katmoget, it'll have a black or brown 'base'.
Place 3: contains either spotted or 'all over colour'. All over colour is dominant, ie you only get spots if the sheep has two spotted genes.

Your apparently black/grey sheep can have a recessive brown gene, and if two brown genes get together in a lamb, it will be brown, even though both parents were black.

[clydesdaleclopper]

This is fascinating stuff

[kanisha]

In this case the white has to be due to white spotting and not the dominant agouti allele due to starting with all greys or shades of. Unless of course one of the shetlands is dominant black......

[jaykay]

Yes, that would be the case in pure Shetlands. I only know their genetics. Do you know what the coat colour genetics are in Gotlands? And I've no idea how they'd combine anyway.

[kanisha]

the genetics of the gotland are quite simple. They are all a single pattern,  another of the agouti patterns like katmoget gulmoget so combine in the same way ie recessive to the dominant white agouti allele but at the same locus - place 1. They are all also to my knowledge black on  place 2 of your description. The variation that clydesdaleclopper is seeing will be due to the shetland genetics which are far more varied.

The warm black of the shetland can be attributed sometimes to  another place ( place 4 if you like) and works like a dilution gene http://www.shetlandsheepinfo.com/FLEECE/modified_colours.htm here it is referred to as a colour modifying gene.

 but its also possible that the "greying" of the gotland is having some effect so it would be interesting to see  photos

[jaykay]

Ah, I wondered if there was a colour modifying gene - I've got lambs this year that appear to show one. Thank you   

[Cheviot]

Hi,
I can't quite get my head around genetics, so I wonder if one of you lovely people who do understand genetics could help  .
For the last two years we have used a white shetland tup on our shetland ewes which are a mix of white, black, katmoget and fawn, all the lambs have been white, so this year we need to change the tup and would like to get one that would hopefully give a mix of colours, what would be the best coloured tup to use?
Regards
Sue

[jaykay]

A plain moorit tup would give you a range of colours - it does depend quite a lot on what the ewes genetics are, but in theory a moorit tup would allow the black, white, katmoget and fawn genes to show through.

Yes, a white tup will often give all white lambs - unless he has a 'hidden' other gene, which it doesn't sound as though yours has.

[Sunnybank]

thanks for all this info, I too am fascinated by the colours and marking of shetlands, i have 9 girls, a couple of black, 3 moorit, a fawn and some katmogets, I have just reserved a moorit tup who will arrive in october so your advice sounds as if i have made a good choice - i choose him because i like the look of him and he is polled. This is my first time with a ram and was worried about horns with my youngest who is 4 and my little helper lol

[sueblacker]

For black sheep, there is a very good paper by Jeanie Muddle (you can find it on Google) and this is focussed on Wensleydales but appears to hold with my black Blue-faced Leicesters: with 2 black parents you have a 90% chance of black offspring and I have actually had 100% for two years.  Black is more common that people think in BFLs and in many sheep (they just get eaten more quickly as the Wool Board pays more for white wool!).
Gotlands can change colour from year to year and also get paler or darker.  The initial black hairy wooll quickly goes into a crimped colour which will be the first coat for shearing, but sometimes the next one will be different.
I had a 7/8 Gotland Romney ewe who regularly produced one grey and one white lamb (off a single Gotland ram).
I love the variety!

[Cheviot]

Hi Jaykay,
Thanks for the reply, just one other question, all our shetland hoggs which will go to the tup in the back end, are white, (from the white tup, that gives all white lambs ) will putting a moorit tup on them throw different colours or do you think they will all be white?
Regards
Sue