DES MOINES, Iowa – Which type of pig carcasses are overvalued or undervalued? A new study funded by the pork checkoff compares carcass measurement systems.
“Understanding carcass measurement systems is valuable in matching types of pigs with the system that best evaluates their amount of lean,” said Rodger Johnson, University of Nebraska.
Marketing pigs is a major challenge for pork producers. Carcass weight, backfat and/or loin depth measurements typically determine the value of their pigs.
Lean predictors. This pork checkoff-funded study developed new fat-free lean prediction equations for procedures used in the industry.
The study evaluated more than 1,000 carcasses via six procedures that packers use to value carcasses.
Fat-free lean composition was evaluated by: carcass 10th rib backfat and loin area; last rib backfat; Fat-O-Meater, an optical probe measuring backfat and loin area; the Carcass Value Technology System, an automatic and computerized backfat and loin ultrasonic scanner; Ultrafom, a non-invasive ultrasonic scanner; and live 10th rib backfat and loin area scan.
Estimations from these procedures were compared to actual fat-free lean as measured and calculated from 10 carcass separation endpoints, then expressed as a percentage of carcass weight.
Through the procedures, regression equations were developed to predict fat-free lean from the six carcass measurement systems used in current harvest systems.
Top methods. The most accurate equations include backfat and loin area carcass measurements at the 10th rib, and the live animal scan that also includes 10th rib backfat and loin area, giving a fat-free lean estimate within ±3.1 percent and ±3.2 percent, respectively, when compared with actual calculations.
Measurement systems using loin depth were less accurate than those using loin area.
Measurements of mid-line carcass backfat were the least accurate.
The project includes carcass separation data from numerous checkoff-funded programs, including the national barrow show sire progeny test in 1996 and 2000, to the quality lean growth modeling project and the genetics of lean efficiency project.
Proceedings from the Estimating Whole Hog Value Symposium, where Johnson presented his findings, will soon be available from the National Pork Board.
Contact 800-456-PORK for details, or go to www.porkboard.org.
