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Post by J & M Chambers on Feb 7, 2016 12:39:21 GMT -5
Hi Kim and others interested in testing for these milk protein traits and Beta Casein A1/A2 testing Neogen - Igenity has the most comprehensive dairy profile testing I have seen for $25 (Igenity Basic) and A2 testing for $12 a test! Neogen - Igenity Dairy Heifer ProgramWe have been doing the Neogen Igenity profile for several years on some of our milkers and we our ramping this effort up now. Not yet enough to make any determinations but we are keeping our eye on a couple of things related to the cheese production protein tests (Kappa, Beta Casein, and Beta Lactoglobulin) along with the Fat, Fat % and Protein tests. In particular, we are looking at both from a human and a calf perspective the combinations of these protein tests and fat (key to my hypothesis) in the desirability of the milk product as liquid milk. Obviously, from the calf perspective, we are basing our observations on cows that calves gravitate to after they've had their fill of their dam and from a human perspective our own subjective tastes and that of a very discerning 8-year-old milk drinker. She can currently identify the milk of one of our cows in a blind taste test from up to 4 other cows. We will see how this goes with more variability. We are trending toward the heterozygous condition on these traits for "drinkability" including Beta Casein A2. or to the extent the heterozygous state is predictive of fat % Anyway, thought I'd share the really neat testing availability through Igenity for those looking at milk and dairy traits. Myself, my family, or Silver Maple Dexters have no financial or other interest in the Neogen - Igenity Corporation. Jeff
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hoperefuge
member
Milking our Dexters in the mountains of KY since 2007
Posts: 101
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Post by hoperefuge on Feb 7, 2016 12:53:28 GMT -5
Very cool, Jeff, thanks for your input. I had looked at the Igenity dairy profile testing quite some time ago, but wasn't sure if it was something to pursue. Maybe I should reconsider. But just an FYI J & M Chambers, your link isn't done right...it just comes back to this thread! Kim
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Post by J & M Chambers on Feb 7, 2016 13:00:51 GMT -5
Thanks Kim,
Now I think it is working.
Jeff
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Post by kansasdexters on Feb 8, 2016 9:49:47 GMT -5
hoperefuge (Kim) -
I added another article link to my other post on this thread. It gives more information on how polymorphism effect in the coding part of the gene is not the only factor in the resulting protein structure. Polymorphism in the non-coding regions of the milk protein is also believed to affect protein transcription. "Because the casein loci are closely linked on Bovine Chromosome 6, the alleles of the different caseins are in linkage disequalibrium, indicating that they share DNA regions which may be involved in the control of protein synthesis. Moreover, because of the linkage disequalibrium the different casein alleles are not expressed against a random combination of alleles at the linked loci. Consequently, aggregate casein genotypes should be considered when estimating genotypic effects."
What that means to me, is that I have to be able to compare the performance of a set of cows with known genetics, in the right combination; and not just single out cows that are homozygous for A2 Beta Casein, and/or just homozygous for "B" variant Kappa Casein, and/or just homozygous for "B" variant Beta-Lactoglobulin. Instead, I'm trying to assemble a set of cows that are homozygous for all three of these preferred alleles, and then measure their performance against cows of the same family group that are not homozygous for these preferred alleles. So I can't look at just one or two cows, or just one or two lactations. I have to collect data over several years to see how consistently the cows in my test group perform against their sister cows (that are managed in the same way and in the same environment) that don't have the same combination of the "preferred" alleles.
Patti
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hoperefuge
member
Milking our Dexters in the mountains of KY since 2007
Posts: 101
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Post by hoperefuge on Feb 8, 2016 11:49:23 GMT -5
Wow, Patti, you're doing an all-out serious study! You go girl. Kim
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zephyrhillsusan
member
Caught Dexteritis in Dec. 2009. Member of this forum since Oct. 2013.
Posts: 1,502
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Post by zephyrhillsusan on Feb 8, 2016 17:43:50 GMT -5
That's the kind of stuff we need people to do, and it has to be breeders with large enough herds to meet these conditions. Anecdotes are nice, but this kind of study will be really helpful! I hope you'll share your results when you feel they're ready, kansasdexters.
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