REA vs IMF help me understand

[Alan]

Reading another post on REA and IMF in Herefords got me looking and thinking, now it is clear as mud. What is, are is there a relationship between REA and IMF? It seems like the bulls I look at if they have a high REA the IMF is lower sometimes in the neg. What am I missing? What does rib eye area have to do with marbleing?

Thanks,
Alan

 

[Frankie]

Reading another post on REA and IMF in Herefords got me looking and thinking, now it is clear as mud. What is, are is there a relationship between REA and IMF? It seems like the bulls I look at if they have a high REA the IMF is lower sometimes in the neg. What am I missing? What does rib eye area have to do with marbleing?

Thanks,
Alan

Good question. I don't know of any correlation between the two. Maybe someone can fill us in. But I do remember that in the first Angus Sire Summary I saw with cacrass qualities, there weren't many bulls with both good ribeye EPDS AND good marbling EPDs. A bull named Scotch Cap bull stood out as having both qualities.

 

[dun]

I've never seen a correlation either. There are those that have acceptable numbers for both, but it seems the majority are either low in one or the other and in some cases both.

dun

 

[SEC]

Generally speaking REA and IMF are antagonistic.

IMF cattle tend not to have as much muscle, i.e. Holstein, Jersey
This would be why we have seen a higher trend towards "funnell butt" cattle.

I always wonder about how much IMF is enough, why isn't middle of the road good enough for people being able to attain some of each trait.

REA- is complimentary to yield, usually. Exotics usually boast great REA.

In the recent times there is a weird thing happening in the cattle that has been hard to explain. There have been some terrific scans by some very ordinary, flat sided cattle. Nobody would ever have guessed these animals to have scanned a REA like they have.

It seems that there may be a correlation between lack of sexual maturity and these bizarre ultrasound scans. This isn't always the case but often times it is sure working out that way. This would explain the re-emergence of the Precision bloodlines as 7-8 years ago, nobody cared about 1680. These cattle along with the New Designs and a few others have scored excellent CUP data but aren't very masculine, lots of them look like steers or cows. End result has been lots of small scrotal bulls around, fertility will be the ultimate cost. Just ask a few of the guys collecting semen on these bulls.

 

[Hill Creek Farm]

A bull that comes to my mind when you talk about IMF and REA is Feltons Legend 242. Legend has a big IMF EPD number and also a high REA number. I think that Feltons Endurance 745 was the same way. I am not a true fan of Feltons Legend 242.

 

[LFF]

Generally speaking REA and IMF are antagonistic.

Correct!!


One thing else to consider is that larger frame cattle will naturally have larger ribeye are. Doesn't mean smaller framed cattle can't , just that ribeye is measured in square inches and cattle with more body mass naturally have more area.

 

[SEC]

THis is why REA per 100lbs is the most important rather than the size.

 

[Badlands]

REA/BW tends toward picking younger and smaller mature weight animals.

It's really not too much good to do much else with, unless the animals you are choosing from are very close in weight when the measurements are taken.

Babhy calves will always have higher REA/BW on the average than the same animal as it grows.

Miniature cattle will always have higher REA/BW on the average than cattle that increase in size from there.

Badlands

 

[Jeanne - Simme Valley]

REA/BW should be adjusted to 365 day in order to be usefull. Than it gives you an accurate number to pick the TYPE of bull you are looking for. Early/late maturing, big/small frame, Hereford/Charlolais, etc.

 

[SEC]

What I was meaning was scanning cattle at or near 365 days of age. I am not thinking baby calves at all.

If it all gets adjusted to a year of age and the bulls are fairly close to a year of age or same birthdate it's beneficial.

 

[Frankie]

A bull that comes to my mind when you talk about IMF and REA is Feltons Legend 242. Legend has a big IMF EPD number and also a high REA number. I think that Feltons Endurance 745 was the same way. I am not a true fan of Feltons Legend 242.

The number of Angus bulls that will give you good marbling and good ribeye has increased greatly since I first noticed Scotch Cap. Breeders need to identify bulls that will work and use them. That's true for all breeds.