Using Ultrasound Technology to Predict Pork Carcass Composition

Abstract

Twenty market hogs were evaluated with real-time ultrasound both before and after slaughter. Fat measures (n = 9) were taken at various body locations along with the longissimus muscle area measurement at the 10th rib. After live ultrasound, the hogs were slaughtered and the unsplit carcasses were measured with ultrasound at the same live ultrasound locations. After chilling, carcass measures were taken at the same locations using a backfat probe for fat measures and a loin eye dot grid for measuring the longissimus muscle area. One side of each carcass was fabricated into the four lean cuts, which then were expressed as a percentage of the side weight. The most appropriate prediction equation found was a two-variable equation (fat thickness at the anterior tip of gluteus medius and longissimus muscle area) with a R2 of .83 and a RSD value of 1.67. This prediction equation was verified on a different sample of 20 market hogs; actual vs predicted four lean cuts revealed that the prediction equation had a R2 of .63 and a RSD value of 2.04. Although some accuracy and precision was lost when this live animal prediction equation was incorporated in market hog evaluation, this equation offers producers an objective mechanism for identifying carcass merit in live hogs.

Commercial adaptation of ultrasonography to predict pork carcass composition from live animal and carcass measurements1

“…The two data sets, one used to develop and one to test the prediction equations, are quite similar. Average LWT of the two groups closely approximates the weight of animals used in several other studies of a similar nature (Grisdale et al, 1984;Siemens et al, 1989;Terry et al, 1989). However, the SD of live weight in the present study is slightly larger than some reported previously.…”

Prediction of live and carcass characteristics of market hogs by use of a single longitudinal ultrasonic scan

“…negative for BNLSCUTS, TOTLCUTS, BNLSPCT, LEANPCT, TOTLPCT, and BODYPCT and is positive for NPPCLEAN. This negative relationship might be unexpected when so many studies (Simm, 1983;Forrest et al, 1989;Terry et al, 1989) have reported a correlation between longissimus area and carcass composition. However, when weight and fat depth are included in the prediction equation, the need for longissimus area or other direct estimates of muscling t o estimate carcass composition might be questioned (McLaren et al, 1991;Gresham et al, 1992;Smith et al, 1992).…”

Prediction of carcass lean content by real-time ultrasound in Pietrain and negative stress Pietrain

“…Gresham et al (1994) suggested that a single longitudinal scan taken at the 10th rib was accurate for predicting carcass composition but did not include scans at other positions. Equations based on ultrasound scans have been shown to explain more variation of the dependent variables than those based on direct carcass measurements taken at the last rib (Terry et al, 1989;Cisneros et al, 1996). There are few reports in the literature for regression equations predicting carcass composition separately for the different halothane genotypes.…”