inheritance

[knabe]

just read an interesting article in "thescientist" titled mendel upended.

very interesting.  what is proposed is a storage mechanism for revertants to wild type that may be rna in nature as a template to use to revert and incorporate back into the genome.  other mechanisms are very large insertions, up to 5700 base pairs, as a result of environmental conditions, and is heritable.  this would be another mechanism other than methylation that would store environmental information and allow an organism to accumulate adapatation.  this may explain why it may take a generation or two for outcrosses, though outstanding to show an effect and why some people may experience average results from supposedly superior individuals.  a superior individual who had accumulated environmental factors in their genome, could actually perform far worse when moved to a different environment.  this may explain why individuals which contain both TH and PHA are so unique.  it would be interesting to determine if these mutations are inducible, not that we would want to do that, but that if it was possible, one could easily think of a production system to impose as being just as if not more important than genetics and epd's from different environments.

obviously one would have trouble reverting being homozygous recessive lethal.  i wonder though if the ratio of mating carriers to carriers might have a population that violated 1:2:1 and had revertancy.  i know, it's a stretch, since the calf can obviously grow a lot, while in plants, if it's lethal beyond the one cell stage, that's a different selection criteria.  I wonder if herda in quarter horses is the same.

still would like to see the sequence of the PHA gene lined up with say 50 each offsrping from irish whiskey, paramount, dalton, stinger, draft pick, ice pick, 4072 cow, XL 26K ET, etc, who by the way finally showed up as PHAC in this month's list in the voice.  i have a direct daughter from this cow, and she is PHAF, and her daughter from a confirmed carrier bull is also free, which, i know, i've repeatedly stated ad nauseum. 

also in the voice, in the article about carcass "progress" it was mentioned there were 3 markers for QG.  There are 4.

 

[simtal]

also in the voice, in the article about carcass "progress" it was mentioned there were 3 markers for QG.  There are 4.

You think that these markers are the real deal, mainly QG and Feed efficiency?

Measuring quantative traits on a qualitative scale seems misleading, IMO. 

I say this I guess, because I'm part of a long term effort that will ultimately go into QTL.

 

[Telos]

Will have to 'google' methylation first, in order to get a grasp of what you're trying to convey here Knabe. Is it correct that viruses are made up of RNA and not DNA and they  readily mutate?  It would be an interesting discovery to find out if Neanderthals carried marker genes for autism, which was a trait that was well adapted for their environment, and then hybridized with Homo Erectus after being separated for nearly 700,000 years. Dr. Grandin believes people with autism thinks similar to animals of prey.

I hope some of our SP youngsters have an interest in Molecular Science. I think we are still in an infant stage of knowledge with regards to this science.

Do you think Dr. Beever's findings will shed some light on some of these purposed theories?

 

[Telos]

Did some homework on methylation and epigenetics etc. and have concluded this goes over my head.  ??? 

Knabe, you have a way of making me very humble.

 

[knabe]

also in the voice, in the article about carcass "progress" it was mentioned there were 3 markers for QG.  There are 4.

You think that these markers are the real deal, mainly QG and Feed efficiency?

Measuring quantative traits on a qualitative scale seems misleading, IMO. 

I say this I guess, because I'm part of a long term effort that will ultimately go into QTL.

i'm hesitant about the feed efficiency ones.

the marbling may have an overall low contribution, but i think we are underestimating envrironmental effect on marbling, which includes production methods, time of year of harvest etc.  genetically, i think the markers may increase this by 10-15%.  still, if genetics is 40-60% of marbling, a 5% improvement is really a 12.5% improvement at the 40% level if genetics is only 40% of the contribution.

with the tenderness genes, realizing that the longer they hang, the more a tenderness marker and no marker converge, the benefit will be less days required to hang for a tender product.  this translates into less freezer storage time for a relatively dramitic improvement in a short period of time, ie a week versus say 3 weeks.  one week or less is sufficient to make a tough carcass tolerable and sellable as a tender product on the high end.  a 6 star tender carcass may be 2.2 lbs more tender than a no star carcass.  a tough carcass is about 12 pounds shear force.  a 6 star animal will be about 18% more tender.  that's something i can sink my teeth into rather than chewing into it.  what i'm really after is a more tender tritip and other cuts than a more tender filet or rib eye.

 

[simtal]

I agree with all of that.  I guess any improvement is good.  I've heard mostly mixed opinions about this.  Some say that these markers are for cattle that have poor/no numbers.  The tenderness thing, I had a professor tell me once that "forget all the research with tenderness regarding selection, nutrition, etc... if we could just hang 'em all longer tenderness wouldn't be an issue".

 

[knabe]

i posted this a while ago.  notice the spread goes from 0.5 kg shear force to about 0.2 after 3 weeks.  multiply these numbers by 2.2 to get pounds force.

so, to compare a "0" star carcass with a "6" star carcass, take 6.06*2.2= 13.32 pounds, then subtract 2.2 pounds, and you get 11.12 pounds, well under the so called "tough" carcass value at 12.54 pounds with ZERO aging.  (funny how the conversion for kg to pounds is also 2.2).

i haven't been able to find the same table with a 6 star carcass and what the converge lines look like after 3 weeks.

sorry for all the jumping around in units.  below is the previous post.
____________________________________________________________________________________________________________________
The key to good meat is hanging it an extra week.

i can back this up with facts.  i posted this on another website.  it's pretty easy to get tenderness gene results by that extra week and on down the line.  pretty amazing.

in the paper
"association of a single nucleotide polymorphism in the calpastatin gene with carcass and meat quality traits of beef cattle" by schenkel et al there is a table. remember, this is only for one gene and measures all 3 allele types. also, remember, a tough steak is rated as one that is 5.7 kg on shear force test or 12.54 pounds.  you can see that if you have the CC allele, you barely have a tender steak for this one gene at two days, but at JUST 7 days hanging, the worst carcass is better than the best carcass at two days!  even more dramatic at 14 days.  i haven't seen any data on carcasses with homozygosity at all three alleles compared to the no star carcasses.  can one have negative tenderness?  in the end, perhaps it just means one can save on energy in the locker and have the best tenderness at 7 days the same as 21 days.  pretty amazing.

here is the table. x is shear force at days post mortem
y is the genotype and units are kg force. (variation not shown)

        2        7    14    21

CC 5.55 5.03 4.23 3.67    this is the homo data for T1 i believe
CG 5.81 5.13 4.39 3.95    this is the hetero data
GG 6.06 5.41 4.44 3.87    this is the data with no tenderness marker

they have a unit called SFLavg which kinda groups the differences altogether in one number, but i like the table as it shows, as usual, a practice window to excel.

also of note, one could purchase lower cost, low star carcasses and sell them as premium simply by aging and get a similar product depending on how the star carcass was handled. REMEMBER, this is only for one gene.


so it would seem that all you have to do is age the carcass 7 days to get under the magic 5.7 kg. that's a huge difference between on the 2 and 7 day time points, but dramatically gets smaller the longer you age. no one really ages that long without a little hassle (21 days), ie drier aging units to remove moisture so mold doesn't build up, wrapping the carcass with cheesecloth to make mold removal easier. also, quartering the carcass wastes an excellent steak. someone told me yesterday that they would feed carcasses at cost for the profit they make off of offal for a period of time to hold them over during tough price points. a guy at the feed store told me the other day he had one age for a month, but it had lots of mold, but after cleaning it up, he said it was the most tender beef he had ever had. going to go ask a local butcher today about their dry aging.

ps, there is one other paper i am trying to read which i lost for other markers with real data. airhead moment. i'll try and find that one.


PS again.  would like to know if this is what safeway does with ranchers reserve and if it's cheaper for them to purchase the cheaper carcasses, hand required number of days and sell it at a premium called "ranchers reserve" rather than paying up front for better quality carcasses.

 

[knabe]

I hope some of our SP youngsters have an interest in Molecular Science. I think we are still in an infant stage of knowledge with regards to this science.

Do you think Dr. Beever's findings will shed some light on some of these purposed theories?

that first sentence is the understatement of the year.

Dr. B's findings seem to be at this point single gene mutations.  the next step for everyone, is the multigenic traits.  sorting this out from methylation and other factors will be interesting.

bred my backdraft cow to pendleton on monday.  the midas cow gets wild turkey.

 

[aj]

The thing is about hanging meat the extra time will not work on a grand scale. The big meat companies are all about effiency and inventory controll. You almost have to have a specialty market(upscale) to justify the extra hanging time....in my opinion.

 

[knabe]

The thing is about hanging meat the extra time will not work on a grand scale. The big meat companies are all about effiency and inventory controll. You almost have to have a specialty market(upscale) to justify the extra hanging time....in my opinion.

which is why i think the tenderness markers have some merit.  it's pretty easy to get under the threshold for tenderness with a minimum of hangtime, especially over the weekend when marbling can blossom too.

 

[garybob]

The thing is about hanging meat the extra time will not work on a grand scale. The big meat companies are all about effiency and inventory controll. You almost have to have a specialty market(upscale) to justify the extra hanging time....in my opinion.

which is why i think the tenderness markers have some merit.  it's pretty easy to get under the threshold for tenderness with a minimum of hangtime, especially over the weekend when marbling can blossom too.

Yes, I think that the longer a carcass hangs ( within reason), tenderness is enhanced. Tyson ain't got time for that, though.

GB