Much as the new production and financial terms and standards were developed to help pork producers and their lenders more accurately evaluate their businesses, the newly revised Fat-Free Lean prediction equations can be used to standardize and compare different carcass measuring methods.

The Fat-Free Lean prediction equation or FFL can be used to give an accurate measure of the pounds of lean pork produced even when pigs are sold to different packers using different carcass measurements.

Originally introduced in 1994, the equations have been updated using data from the National Pork Producers Council (NPPC) Quality Lean Growth Modeling Project (QLGMP) completed in 1998. This project included the most comprehensive carcass separation and lean content evaluation ever undertaken. Over 690 half-carcasses were separated into lean, fat and bone. The lean, fat and other soft tissue were then analyzed for total lipid content and the total lipid free lean (Fat Free) was calculated.

The carcasses were from a sample of market pigs that varied greatly in genetic type, diets fed, sex and slaughter weight (190-360 lb.) The average slaughter weight was 289 lb., reflecting the need for information about heavier market hogs. Previous Fat-Free Lean prediction equations were based on historical, university carcass separation data, often at 200-250 lb. weights and representing genetic types of 10-30 years ago. The genetic types represented in the development of the updated FFL prediction equations represented in the QLGMP crossbred market hog group were Berkshire, Danbred, Duroc, Dekalb Swine Genetics, Hampshire and Newsham Hybrid.

New FFL prediction equations were developed for five types of measurement: last rib Ruler systems, Fat-O-Meater, AUS ultrasound systems, live animal real time ultrasound scans and loins broken at the 10th rib. Even though the broken loin measurement is the most accurate, it is rarely used due to the damage to the loin that must be discounted. Equations including genetic type, diet and sex effects are included in a new NPPC publication. (Copies are available by writing National Pork Producers Council, P.O. Box 10383, Des Moines, IA 50325 or calling (800) 456-7675; also see NPPC's Web site at

Most producers will use one or more of the following four FFL equations to determine their lean pork production. These equations use fat thickness, loin muscle depth or area, and carcass weight to predict pounds of Fat-Free Lean. The SCAN live animal equation will be useful at market hog shows when actual carcass measurements cannot be obtained.

The information needed for producers to calculate total Fat-Free Lean can usually be taken from packer market reports. Some packers may adopt these equations and automatically provide the pounds of FFL on their market reports. Producers or packers wanting to calculate FFL percentage should divide the pounds of FFL by the carcass weight, then multiply by 100.

In addition, producers may wish to calculate the feed-to-FFL efficiency ratio to help determine their production level. Production cost of FFL/lb. helps target profitability.