The relationship of selected visual and objective live animal measurements to carcass length in swine

Surveys have indicated that consumers prefer high quality lean cuts of pork in preference to those cuts which are excessively fat. A decreased demand for lard, consumer resistance to fatty foods, more specialization in meat marketing, and selection for improved production traits have increased the need for improved evaluation techniques in swine breeding and selection.

The advent of swine certification programs created a need and desire for simplified methods of measuring certain conformation and/or carcass traits on the live animal. Such methods would allow extensive information to be obtained without sacrificing potentially superior breeding animals.

Backfat thickness, carcass length,and area of the longissimus dorsi muscle have been used extensively as measures of carcass desirability in swine certification programs. Research studies indicate that backfat thickness and loin eye area may be determined with a high degree of accuracy on the live hog. Probing hogs for backfat thickness has proven to be a practical and useful tool to select those hogs which have less backfat. Ultrasonic evaluation techniques have been introduced in recent years and serve as a tool to measure depth of backfat and area of loin eye.

The relationship between live animal measurements and carcass length has not been studied extensively in swine. There is general agreement in swine carcass studies that a low correlation exists between carcass length and carcass cut out value. On the other hand, there is limited research evidence that added length in swine is associated with greater sow productivity.

This study was undertaken in an effort to develop a method of predicting carcass length in swine from certain live animal measurements. The relationship between carcass length and certain carcass traits also was studied.