Igenity vs. Pfizer HD50k tests

[CLMAngus]

I only know a little about these tests and was wondering about the effectiveness compared to each other.  I know the HD 50k uses 54,000 markers and I'm guessing Igenity uses fewer because of the price difference.  However, will the HD 50k test allow the animals EPD accuracies to be considerably higher than the Igenity?  The reason I ask is I have a bred Angus heifer who is currently sitting in the top .5% of the breed for WW and YW numbers and a decent +2.6 BW, but of course low accuracy.  The man I purchased her from informed me that out of 5 or 6 half siblings (same donor dam), all their WW and YW numbers went up while BW went down after genetic testing.  He did not know enough to compare the two AGI tests though and was unsure about accuracies.  So in summation, Igenity vs. HD 50K..  Thoughts, comments, questions; flood them here.

 

[knabe]

ugh.

 

[leanbeef]

Generally speaking, whether or not those tests have any affect on an animal's EPDs depends on the breed association involved and whether or not they use the data to enhance the numbers. I'm not sure if they'll use the information from Igenity's profile or not, but in the case of the Pfizer test, yes...the accuracy levels should resemble the accuracies after having a handful of progeny reported. I was at a meeting recently where Simmental discussed the affect the MBV would have on low accuracy EPDs & they're saying it's like have 13 calves reported...accuracies should be in the 40 percent range?

 

[knabe]

i think companies have this backwards.

if they know which piece of dna they think is needed for a response, they should allow a way to track, introgress that.

an epd is too susceptible to variation due to inheritance. 
you could have a bull that is hetero at 50% of the markers or homo for 25%.
assuming all markers have the same impact, both bulls may be equal, assuming additive and epigenetic effects.
as number of offspring accumulate, accuracy will obviously peek through variability.
so if you have a low number of individuals but a lot of info on a diverse set of individuals, these companies won't help you.

i think it's a load of crap at the moment.

yes, i still use them, yes there are differences between individuals that are sortable for traits at some point.

i am using it as somewhat of a diversity verification mechanism to catalog sources.
yes, it's interesting  to note that marker homozygosity rates seem correlated with the parentage markers with the individual markers from bovigen.
yes, i've found all the original set of bovigen markers in fullbloods, yes, i've found individuals with high and low scores on igenity, yes i'm skeptical.

yes, if there are things that matter, at least there is some variability left within the maine breed to see look for stuff.
yes, the maine breed could just be stuck with the marbling they have and there is little variability to play with.

but, at least these stupid companies could help if they would just pull their head out for the people who can handle the data.
what are they scared of?  the markers don't work?
they already have pretty much said they don't work across breeds.
oh well.

 

[DKT Angus]

While at NJAS in Louisville, 50k was a clinic they held and from my understanding on how it works is as follows:

Basically gives a animal a 10-15 calf head start
You may or may not have a result in your favor and regardless of weather it's in your favor it WILL change his/her epds and acc. numbers in the herd registery
If i remember correctly a acc. could change anywhere from something like .1 to .3 (I may be wrong i don"t remember it all)

If she is in the top .5% as you say I would waste your money and possible risk her number going down.

 

[leanbeef]

Knabe...I don't understand a single word of that...

DKT...That's basically the way I understand it. The number I heard is 13...the 50k test will bump accuracies up to what you'd have with 13 progeny recorded. Obviously, the lower the accuracies, the greater the possible change in EPD and the greater the increase in accuracies. A 50k test on a yearling with no progeny recorded would have accuracies in the range of 40%

High accuracy bulls are good for the system as a quality assurance check on the test, but there shouldn't be a lot to learn about the bull if his accuracies are already high.

I understand your thinking from a marketing standpoint...if the numbers are good, doing the test chances the EPDs moving in the wrong direction. From an animal breeding standpoint, do you want good numbers or do you want to know where she falls in the gene pool? That philosophy is the same as not breeding her because the calf might not be as good as you hope it is.

I think we could help ourselves if we could all be more objective about our own cattle and be less motivated or concerned with self-serving biases.

 

[knabe]

Knabe...I don't understand a single word of that...

basically it means "doing the test chances the EPDs moving in the wrong direction."

hence, it's not a quality check, pure and simple.

there is a difference between correlated and causal.

the companies don't yet know what is causal.

 

[HACC]

We've tested several of our herd bulls (Charolais) with both companies and think Igenity is the best option at this time. Our breed is just starting to use this information for EPD calculation and it will be interesting to see how it effects the data base. <party>