Too Much Fat on the Hide Side: Backfat and the CAB Line

You want fat inside the steak and not much on the outside. Marbling is the fat that makes the beef eat well. Backfat is the fat on the outside of the carcass, and the packer trims it off and throws it away. Certified Angus Beef wants the first and limits the second to one inch. If you feed cattle, you have to balance both.

Why the limit is there

Backfat is usually measured over the ribeye at the 12th rib. It does nothing for the eater. It is trim. The more of it there is, the less of the carcass becomes saleable lean. The USDA beef grading system uses fat thickness along with ribeye area, carcass weight and internal fat to calculate yield grade, so more fat pushes a carcass toward a worse yield grade. Our guide to ribeye, backfat and hot weight walks through those lines. The brand caps backfat at 1 inch.

How often it is the miss

Less often than you may think. The Angus Journal's column on the brand says backfat over 1 inch was behind 9.8 percent of the non-qualifying carcasses. Marbling was 81.8 percent, weight 14.5 percent and ribeye 9.5 percent. Carcasses can miss on two counts, so they add up to more than 100. Be careful with that 9.8. It is a share of the misses. It is not a share of all your cattle. An earlier Drovers report had backfat at 7.5 percent of non-conformance two years in a row and tied it to yield grade 4 and 5 carcasses. Different years and samples give different numbers. Fat is a minor miss compared with marbling.

The part that surprises people

The column reports brand carcasses averaged 0.65 inches of backfat. The misses averaged 0.63. The cattle that missed were, on average, not fatter. Most misses are lean cattle that did not mark. A smaller bunch ran too fat, and they are the ones that fail on backfat. If you look only at the average, you miss the tail. If you look only at the tail, you think everyone is overfed. Both are wrong. Look at the whole distribution on your carcass sheets.

Why a steer runs past the line

• Too many days. He finished three weeks ago and you kept feeding.
• Early-maturing cattle. Some types get fat before they get heavy.
• Heifers. They finish sooner than steers and cross the line sooner.
• The ration and the implant program. Hot rations and growth programs change when fat goes on.

How to stay under

1. Sort before you ship. Ultrasound or a good eye. Send the fat ones first.
2. Market on finish, not on a date on the calendar. Our finishing guide talks about how far to push.
3. Read the carcass sheets by sire group. If one set of calves runs fat at normal weights, that is a bull decision. Farm.fm's page on understanding bulls is a good primer.
4. Chase marbling without chasing fat. The goal is modest marbling at under an inch. Some bloodlines do that better than others.

Do not overcorrect

A man can hear all this and decide to sell cattle light and lean to stay safe. That backfires. Cattle that are not finished will not grade, and you will have a different problem, and the main one on the list. The target is a window. Enough fat cover to protect the carcass and let marbling develop, and not so much you are paying to feed trim. Farm.fm's page on marketing your Angus beef covers how quality and yield line up with price.

What to look for on the carcass sheet

Pick out three columns: backfat, marbling and weight. Put them side by side for each carcass. A steer that is fat and heavy and marbled well was probably fed a little too long. A steer that is fat but did not mark may be an early-maturing type that will never reach the target, and that points to the sire. A steer that is lean and light and did not mark was probably sold too early. Each pattern has a different fix, and the sheet will show which one you have. Do this for a couple of seasons and keep a simple tally, because one pen is a story and five pens are a trend.

Talk to your packer's field rep, too. Most of them have seen thousands of carcass sheets and will tell you how your cattle compare. That kind of free advice is worth listening to.

Where to read more

The Beef Research site and the University of Nebraska beef program publish studies on fat and yield. Specs change, so check the current documents at certifiedangusbeef.com, an independent brand and not part of this site. Your packer's grid controls what you are paid, so read it. For packers, haulers and other help, there is the agriculture directory.

An inch is a generous limit. A man who watches finish instead of just the calendar will keep nearly every steer under it.