White Dexters?

[peastickcowboy]

I've been hearing about solid White Dexters. Has anyone else heard of this?

[dexterfarm]

yes there has been a lot of talk about them. They are not dexters and should not be using that name. they are a white park dexter cross.

[kansasdexters]

White Dexters were developed through an upgrading process utilizing a progression of generations and breeding to a registered purebred Dexter in each generation, selecting for the white offspring, each time. So, in the 1st generation you have a 50% Dexter/50% White Park, in the 2nd generation you have 75% Dexter/25% White Park, in the 3rd generation you have 87.5% Dexter/12.5% White Park, in the 4th generation you have 93.75% Dexter/6.25% White Park, and by the 5th generation you have cattle that are 96.875% pure Dexter, but they are white with black points because that is being selected for and the white pattern is a dominant color type. That is why they are called "White Dexters", and it is an accurate description of this unique offshoot of the Dexter breed. There shouldn't be any confusion about these registered animals because their pedigree certificates are issued through the Miniature Cattle registry and not through either the ADCA or PDCA.

New breeds are created from old breeds through a process of careful, selective breeding (and not just cross-breeding) and that is exactly what this new type of Dexter is. Genetically, these cattle are more than 96% pure Dexter, and the animals that I've seen are much closer to the desired dual purpose Dexter breed type, than the poorly bred, registered "purebred" Dexters that are often found in the United States.

Here is a link: whitedexter.com/



Patti

[hollydzie]

Patti, do they breed true in terms of color? Or can 2 whites have a black calf? Just curious. I have no problem with them, actually I think they are one of the prettiest cattle I have seen with there black noses and tips.

[kansasdexters]

Holly,

The white color pattern is dominant, so if they only have one allele in the gene pair, they will be white. It will take several more generations of breeding the White Dexters with each other in order to build up a population that is homozygous for the white color pattern. Until there are a larger number of the homozygous whites, there will continue to be some black ones born from the matings of the heterozygote whites.


Patti

[hollydzie]

Thanks Patti I find genetics so interesting.

[cddexter]

and by the way, since no one had ever 'copyrighted' the name Dexter relating to cattle, the originator registered the copyright for the name 'white dexter', so they actually have more 'legal' right to be Dexters than ours do.....and as Patti says, they are mostly our Dexter genetics, with slightly heavier bones and a different color. Depends on if you want to be an on-the-ground qualitty or a paper quality person.

For those of you whose knickers are in a twist, none of the founders ever tried to pass them off as conventional dexters, but always as what they are: a new breed based on two old ones, selecting for specific traits: color, size, function, yield. You can't deny they have fabulous eye appeal. cheers, c.

[rhonda]

Years ago I had a White Park. She was one of my favorites..apparently should have kept her! LOL

[peastickcowboy]

If they have a heavier bone structure, what about the height and weight? Are they polled? This sound interesting.

[cathylee]

From the information on their website The White Park color pattern is recessive against the Dexter Black. They did not get the White in the first breeding.

There are similar color pattern crosses with Dexters in Montana. They are Galloway crosses and have the fuller longer coat of the Galloway. At least the ones I have seen listed on Craigslist as bulls for sell have that fuller longer coat. And they are polled. And they say they are part Galloway.

[kansasdexters]

cathylee,

The White Park color pattern is an autosomal dominant trait, only one allele is required in the gene pair for it to be expressed. Please refer to the following: homepage.usask.ca/~schmutz/PaleColors.html (scroll down to the appropriate paragraphs).

Here is an excerpt from the above link:

White cattle, such as White Galloway cattle are quite different from Charolais in that they have black noses and ears. This white is inherited as an autosomal dominant. Heterozygotes are not dilutions of another color but just as white as homozygotes. Their noses and ears can be either black or red or dun. Their underlying skin can be black or red or spotted. The White Galloway cow at the left is shown with a calf that did not inherit perfect white markings. White Park cattle, right, are similarly marked. Although an old breed, from the time of the Druids, they are now quite rare. Speckled Park cattle probably also fall into this category.

The colors of the points in White Galloway can be black or red, which is determined by the MC1R gene, described above, or dun, based on a mutation in the PMEL gene (Schmutz unpublished).

The white body color with colored points appeared to linked to the tyrosinase gene on cattle chromosome 29, based on data collected by Barbara Schmidtz for her Master's degree. Similar patterns exist in the mouse, Himalyan rabbit and the Siamese cat and also are caused by mutations at tyrosinase.

However, this pattern is caused by a very complex mutation in the KIT gene in cattle. A segment of DNA from near KIT on chromosome 6 is inserted onto chromosome 29. Although tyrosinase is near the centromeric end of chromosome 29, this insertion is apparently nearer the middle of chromosome 29. Brenig et al. (2013) further suggests that the whiteness depends on how many duplications of this segment occur.

Brenig B, Beck J, Flore C, Bornemann-Kolatzki K, Wiedemann I, Hennecke S, Swalve H, and Schutz E (2013) Molecular genetics of coat colour variations in White Galloway and White Park cattle. Animal Genetics 44, 450-453
Schmidtz, B.H., Buchanan, F.C., Plante, Y., and Schmutz, S.M. 2001. Linkage Mapping of the Tyrosinase Gene to Bovine Chromosome 29. Animal Genetics 32:119-120
Schmidtz, B.H. 2001. Characterization and mapping of cattle tyrosinase. M.Sc. Thesis, University of Saskatchewan, Canada.
Schmutz, S. M. , J. S. Moker. 1999. In Situ Hybridization Mapping of TYR and CCND1 to Cattle Chromosome 29. Animal Genetics 30:241-242.

[kansasdexters]

If a White Dexter is heterozygous for the White Park Pattern allele and it is bred to a Black Dexter, 50% of the offspring will inherit the White Park Pattern allele and be "White Dexters", the other 50% will not inherit the White Park Pattern allele and they will be black.

Until the White Dexter breed is homozygous for the White Park Pattern allele, breeding the White Dexters that are heterozygous for the White Park Pattern allele will always produce some offspring that do not have the desired white color and black points. Breeding a White Dexter that is heterozygous for the White Park Pattern allele to another White Dexter that is heterozygous for the White Park Pattern allele will produce the following:

25% will be homozygous for the White Park Pattern allele and will be considered "White Dexters"

50% will be heterozygous for the White Park Pattern allele and will be considered "White Dexters"

25% will not inherit the White Park Pattern allele and should not be considered as White Dexters, nor will they "carry" the White Park Pattern allele. If these calves are the offspring of two, IMCA registered White Dexters, they may get registered, but IMO they really should not be registered as White Dexters.

[zephyrhillsusan]

Interesting article on color genetics, thanks. I added it to the links on my blog.

[cathylee]

Thanks, that does make rethink a bit about my breeding plans this year. I'm planning to take my black Galloway cows to meet a white Galloway this year. The same breeder also has a black bull. I was thinking that it was recessive so I thought it would not make any difference this year. It would just leave me the option to try to breed for a white in a couple of years. Since my black cows meet the certified Angus program requirement they are potentially worth a bit more black than white. So I might be less happy with a white steer than a white heifer.

As to the White Dexter trademark I can see that it might have some value. But I think the bulls I saw on Craigslist for the Galloway dexter whites sold pretty fast on Craigslist without registry.

There is a herd of White Park x Dexters in St. Ignatious, MT. I have seen a white steer from there that was chondro positive. He was on the property that had the Dexter bull I used last year. The breeder there had had so many heifers in recent years he hadn't gotten much he wanted to use for meat animals so he bought Dexter cross steers from that farm. That White Park x Dexter farm also has mini Jerseys. The White Park cross Chondro positive steer looked like a little pig. Short and wide. The Dexter Jersey steer (non chondro positive) crosses looked pretty lean.

I will breed my Dexter heifer to a Dexter this year but might in the future breed her to a white Galloway. I would much prefer the polled and longer coat Galloway genetics to White Park genetics. There are lots of Dexter crosses in this area. Wagyu, Lowline Angus, Belted Galloway, white Galloway.

By the way the Belted Galloway belt is also dominant except that some cows carry a "no spot" gene which can trump the Belt gene. The white face is dominant in Hereford crosses.

[israel89]

Beware of purchasing a white bull or cow that has all the black/red points but it is not registered in WDCR registry.First of all the white Dexter name was trademarked and no other breeder can legally use the name.