Backfat Over One Inch: How Excess Fat Costs Angus Carcasses CAB

Fat is part of what makes beef taste good, so it may seem odd that the Certified Angus Beef brand limits it. The explanation is that two kinds of fat matter, and they pull in opposite directions. Marbling, the fat inside the muscle, is what the brand requires. Backfat, the layer of external fat over the ribeye, is limited to one inch. This guide explains the difference, the data behind it and how to stay under the limit.

Two kinds of fat

Marbling is the intramuscular fat you see as flecks in the cut. It improves tenderness, flavor and juiciness. External fat thickness, usually measured over the ribeye at the 12th rib, is trimmed off before the beef reaches the consumer, so it adds cost without adding eating quality. The brand's specification is 1 inch or less. Excess backfat also lowers cutability, which is the percentage of the carcass that ends up as saleable lean. The USDA beef grading standards use fat thickness, along with ribeye area, carcass weight and internal fat, to calculate yield grade, so more fat generally pushes a carcass toward a poorer yield grade. See our guide to reading a carcass data sheet for how that works.

What the data say

The Angus Journal's Behind the Brand column reports that backfat over 1 inch accounted for 9.8 percent of non-qualifying carcasses, with insufficient marbling at 81.8 percent, hot carcass weight over 1,100 pounds at 14.5 percent and ribeye over 17.0 square inches at 9.5 percent. Because a carcass can miss for more than one reason, those shares add up to more than 100 percent. Note that 9.8 percent is the share of the misses, not the share of all Angus carcasses. It would be wrong to read it as nearly one in ten Angus carcasses failing for fat.

An earlier Drovers report on carcass shortfalls put backfat at 7.5 percent of non-conformance in each of two years and tied it to higher yield grade 4 and 5 carcasses. Different years and samples will give different shares, but the story is consistent: fat is a minor miss compared with marbling.

The surprise in the averages

The same column reports that carcasses that made the brand averaged 0.65 inches of backfat, while those that missed averaged 0.63. On average, the misses were not fatter. That seems odd until you remember that the average hides a tail. Most carcasses that miss do so because of marbling, and they tend to be lean. A smaller group of cattle carry too much fat, and those are the ones that fail on the backfat spec. Averages describe the herd, and limits catch the exceptions.

Why some cattle get too fat

• Too long on feed: Cattle that stay past their finish keep adding fat, and weight, at an increasing cost.
• Early-maturing types: Some cattle lay down fat at lighter weights than others. They can be fat before they are heavy.
• Rations and implants: Energy density and growth technologies change the timing of fat deposition.
• Sex: Heifers typically finish earlier than steers and may reach the fat limit sooner.

How to stay under one inch

1. Use ultrasound or visual appraisal to sort cattle before shipping, and send the fattest first.
2. Market on finish, not on a calendar. Our guide to finishing and marbling discusses age and ration.
3. Review carcass sheets. If a certain sire group runs fat at normal weights, factor that into mating decisions. Farm.fm's page on Angus genetics for quality and profitability covers balanced selection.
4. Balance fat and marbling. The goal is to reach modest or higher marbling without crossing 1 inch of backfat. Some genetic lines do this more efficiently than others.

A balanced view

It is tempting to treat fat as the enemy, but cattle without enough finish will not grade. The target is a window: enough fat cover to protect the carcass and allow marbling to develop, and not so much that cutability and the brand limit are lost. The Beef Research site and the University of Nebraska beef program publish studies on how fat and yield interact. Farm.fm's page on boosting Angus market value touches on how quality and yield feed into price.

Reading your own carcass sheets

The most useful thing a producer can do with this information is to look at their own data. For each carcass, compare backfat with marbling and weight. A carcass that is fat, heavy and well marbled was probably fed a little too long. One that is fat but lacks marbling may come from an early-maturing line, which points to the sire. One that is lean and light and did not mark may have been sold too early. Each pattern suggests a different change, and a few seasons of tallies will show which pattern is yours. Packer field representatives who review sheets for many feeders can also offer a useful comparison.

Before you decide

Specifications change, so check the current documents at certifiedangusbeef.com, an independent brand not affiliated with this website. Packer grids also differ, and your own contract controls what you are paid. For service providers, the agriculture directory is a convenient place to look.

One inch is a generous limit for most cattle, and a good feeding program keeps nearly all of them under it. The producers who watch finish, not just weight, usually stay comfortably inside the line.