title: Evaluation of the prediction of alternative measures of pork carcass composition by three optical probes.
abstract: The accuracy of 3 optical probes (HGP4 Hennessey Grading Probe, Destron-Feering PG-100 probe, and Giraldo OPTO-Electronic PG-200 probe) to predict the carcass percentage of 5 alternative measures of carcass composition (fat-tissue-free lean, lipid-free soft tissue, lipid-free lean, total fat tissue, and soft tissue lipid) was evaluated on 203 barrows and gilts of 7 genetic populations. The optical probe backfat depths were more closely correlated (P < 0.001, 0.963 to 0.983) than the LM depths (r = 0.695 to 0.734). The optical probe backfat depths were related to lean percentage (r = -0.82 to -0.88), total fat tissue percentage (r = 0.84 to 0.88), and soft tissue lipid percentage (r = 0.86 to 0.87). Optical probe LM depths were weakly related (P < 0.05; r = 0.23 to 0.34) to measures of carcass lean percentage and total fat tissue percentage (r = -0.16 to -0.26). Fat-free lean percentage was predicted with residual SD (RSD) of 3.7% for equations including last-rib midline backfat thickness, 2.4 to 2.7% for equations including optical probe backfat and LM depth, and 2.3% for ribbed carcass measurements. The RSD for the optical probe equations ranged from 2.1 to 2.4% for lipid-free soft tissue percentage and from 2.0 to 2.3% for lipid-free lean percentage. The RSD for the optical probe equations ranged from 2.9 to 3.3% for total fat tissue percentage and 2.5 to 2.8% for soft tissue lipid percentage. Quadratic and cross-product variables of optical probe fat depth, LM depth, and carcass weight were significant (P < 0.05) and reduced the RSD of the equations. Optical probe backfat and LM measurements can be used to predict alternative measures of carcass composition. The predicted relationships in fat-free lean percentage to backfat depth were nearly identical for each optical probe.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907-2054, USA. aschinck@purdue.edu
authors.forename: A P
authors.initials: AP
authors.lastname: Schinckel
authors.forename: J R
authors.initials: JR
authors.lastname: Wagner
authors.forename: J C
authors.initials: JC
authors.lastname: Forrest
authors.forename: M E
authors.initials: ME
authors.lastname: Einstein
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D005223:Fats / Q000032:analysis; D005260:Female; D008055:Lipids / Q000032:analysis; D008297:Male; D008460:Meat / Q000032:analysis*; D008462:Meat-Packing Industry / Q000379:methods; D018482:Muscle, Skeletal / Q000737:chemistry; D013552:Swine / Q000378:metabolism*
chemical_list: D005223:Fats; D008055:Lipids