AS-376 • Rev. 1977
animal sciences swine
COOPERATIVE EXTENSION SERVICE, PURDUE UNIVERSITY, WEST LAFAYETTE INDIANA 47907
How to Make Backfat Determinations
K. J. Drewry, Animal Sciences Department, Purdue University
Several traits are considered economically important when measuring the "profitability" of swine. Profitable swine are those which will return the most to all people associated with the industry. The ultimate goal should be the production of quality pork carcasses that meet the desire of the consumer.
Justification for deciding which traits to measure in the live hog depends upon the heritability of the trait (measure of differences due to genetics) and the relative economic importance of the trait. The swine producer, as well as the Seedstock supplier for the producer, determine the kinds of hogs and resulting carcasses which will be available for marketing, packer and retail personnel to merchandise.
What are the traits that affect the economics of these swine-related industries as well as the producer? The traits are: muscularity, prolificacy, growth rate, feed conversion, structural soundness, and backfat. They range in heritability from
low (prolificacy) to medium (growth-rate, muscularity, feed conversion, structural soundness and backfat). The relative economic importance of the traits vary according to the section of the swine industry in question.
This publication will deal only with backfat determinations in live hogs and its relationship to the goal of producing quality pork carcasses in volume.
Table 1 shows the average carcass measurements, listed by various classes of average carcass backfats, for 4000 hogs evaluated through Indiana Swine Evaluation Station from 1957 to 1969. The values in the table show, with comparable weight carcasses, that each additional 1.0 inch of carcass backfat results in a decrease of about 5 percent (7 pounds) in ham and loin. This gives some idea of the importance of additional backfat on the 160-pound carcass from a 230-pound live hog.
Table 1. Average Carcass Measurements for Various Backfat Classes/
‘From Indiana Swine Evaluation Station data. “Includes trimmed hams and loins as percent of chilled carcass.