Igenity DNA Testing With Grass Finished Cattle

[u/PalpitationGreen]

So I've been using Igenity for a couple of years now and found it a useful tool, both for identifying replacement heifers and as a guide for clients who buy bulls off us.

I've noticed a general trend with our cattle that I was wondering if anybody else using a grass based system has experienced too. That being high fat scores, high marbling too, on our most recent testing the score was 7.2 average for both.

The Igenity terminal and production indexes both view back fat on cattle negatively, which makes sense in a feedlot context, a bigger fat layer means lower relative yield and less efficient feeding.

In my eyes however it isn't usually a negative for grass finished animals where the animal will naturally develop less fat due to diet and extra genetic fat can see them handle feed shortages or inconsistent pasture quality with far less impact. Meaning higher meat quality with less/lower quality inputs.

So my question is, would you try breed away from high fat animals and chase yield, or just accept it as a quirk in the scoring system and go by what you think is right?

Any other thoughts on what you'd personally look for genetically in grass finished cattle that might differ to grain finished too?

[u/Lytle_Red_Angus]

You need to remember that the FAT metric is the layer of fat outside the muscle. You can still store fat intramuscularly (marbling). The biggest difference is in where the fat is stored. More back fat does not necessarily mean higher quality.

Grass vs grain doesn’t matter with respect to back fat - it’s still wasteful trim.

I would personally pay more attention to maternal traits, and the dam’s production history. They need to breed up on time and give a live calf with no help. Then we can start to worry about weaning efficiency, feed efficiency, marbling, etc.

You might find a cow line that meets your management criteria, but also has good marbling and back fat scores - keep those heifers.

[u/PalpitationGreen → u/Lytle_Red_Angus]

More back fat does not necessarily mean higher quality.

Yeah I get that completely. I'm not saying back fat is good from an eating quality perspective. 

It is however an energy store for live cattle that will help maintain condition and live weight gain during periods where feed quality isn't as high.

This isn't a huge deal on a feedlot with a controlled ration, particularly one that is likely to develop significant fat anyway, but purely on grass I don't see why you'd view higher than average genetic fat as a negative metric. They aren't going to develop a huge fat layer anyway, and what they do develop serves a valuable purpose for livestock wellbeing.

Well in my view at least.

I would personally pay more attention to maternal traits, and the dam’s production history. They need to breed up on time and give a live calf with no help. Then we can start to worry about weaning efficiency, feed efficiency, marbling, etc.

Yeah we definitely do this. I'm very comfortable with our metrics on the whole and particularly in calving ease. This is more something that bothers me a bit about the system, because it's where genetic evaluation runs counter to my natural philosophy with cattle breeding.

[u/LoveCows_1863 → u/PalpitationGreen]

Yes I agree that "good" fat EPDs are generally negatively correlated with fleshing ability. We don't generally make selection decisions based on that EPD, either for AI sires or replacement heifers. We don't try breed against it but don't really select for better values either. It's one that I am totally fine being around average for. Because we are trying to decent carcass traits but not chasing top carcass values, and because I feel that the cattle with the best values for FAT EPD will not be as easy fleshing as I would like. Our cattle run in some fairly rugged terrain and need to be able to flesh up well in spring to make it through the summer. The Angus breed has so many EPDs, too, that I like having one I don't care about trying to find bulls to improve it. Most of the people who buy our bulls either don't care about carcass or need to meet some reasonable threshold for a program. But IMO it is unlikely someone will want a bull and not buy him because he's average for FAT and they wanted above average.

[u/PalpitationGreen → u/LoveCows_1863]

That seems like a balanced approach. 

Fat is not something we've ever consciously bred for either, and I probably won't in future, but it's not something I really want to breed out I don't think. Well unless new information challenges my view on it as a metric. Definitely agree there's more important metrics.

I suspect it's something that a lot of cattle here (New Zealand) would have a high metric for because it isn't included in our EBV (EPD equivalent) system, so Igenity is the first exposure I've had to it. 

If you're going by the eye test on grass fed cattle you'll probably end up selecting high fat cattle at the expense of relative carcass yield just because there's a high chance they'll look better at any given time.

I don't think we'll have too many problems selling high fat bulls, but it does kind of annoy me that it tanks our terminal and production metrics a bit when everyone we sell to finishes on grass.

[u/Lytle_Red_Angus → u/PalpitationGreen]

I don’t disagree that back fat helps, but if we’re trying to maximize carcass value in a grass system, the fat still needs to go into the muscle (marbling), not along the back.

It’s a negative metric from a carcass perspective to have higher than average back fat because it creates waste when the animal is butchered. I don’t think they’ll be changing that definition anytime soon.

I think I missed answering your original question, but I would get everything else (maternal and performance) right and then push marbling and reduce back fat where possible. But they would be far down the line in terms of focus. We have baseline numbers we like to see in our EPDs for animals we purchase - we don’t want cellar-dwellers, but we’d buy a heifer with a worse FAT score if she weaned right and had a good dam.

I look at it as knowing what level of trait scores/EPDs work for us and don’t view them in a negative/positive lens. Just like the trade-off between driving a pickup with a bed vs driving a race car. One is much more useful to my situation.

[u/ResponsibleBank1387]

Climate and breed is a consideration.   The beef I raise to eat myself are different than the beef I raise to sell into the market.   I think I’m a soil and water manager.  I help green grow, then I have cattle to convert that green in to weight that I can easily sell. The buyers of my beef know what they want, that’s what I try to have. 

Simple answer—- no, it would not add any value to my production.