Relationship of liver abnormalities with carcass performance and value*

We evaluated the association of liver ab- normalities with carcass characteristics and value, using 2 independent databases generated from 2010 through 2021. Liver abnormalities (ab- scesses, congestive heart failure CHF, flukes, telangiec- tasis) and associated carcass outcomes were evaluated for 371,476 carcasses housed in database 1. Liver abnormali- ties of individual carcasses (n = 1,166,056) in database 2 were captured as lot-level (n = 7,196) audits and summa- rized as frequencies across demographic categories. Data were analyzed with mixed models. Livers were scored as fol- lows: edible = no abscess or abnormality, A− = 1 to 2 small abscesses or inactive scars, A = 1 or 2 large ab- scesses or multiple small abscesses, A+ = multiple large abscesses, A+adhesion (A+AD) = liver adhered to part of the gastrointestinal tract or diaphragm or both, A+open (A+OP) = open abscess, A+adhesion/open (A+AD/OP) = combination of A+AD and A+OP score. Other non- abscess liver abnormalities recorded were CHF = dark mottled blue appearance and noticeably enlarged; flukes = presence of black lymph nodes, enlarged thickened bile ducts, visible dark tracts scattered throughout the dorsal side of the liver, or presence of flukes within the liver; and telangiectasis = peppering of blue/red dots on the surface of the liver tissue. Liver abnormality rates across both da- tabases were A− = 7.3% to 7.4%, A = 2.7% to 5.3%, A+ = 2.4% to 4.8%, A+AD = 3.9% to 6.2%, A+OP = 1.4% to 1.7%, A+AD/OP = 0.8% to 1.3%, CHF = 0.1% to 0.2%, flukes = 1.3% to 3.6%, telangiectasis = 0.6% to 0.7%, with 67.0% to 77.0% of livers being edible. Carcasses with se- vere abscesses (A+, A+AD, A+OP, A+AD/OP) or CHF had less hot carcass weight (HCW; 13.0 and 42.5 kg, re- spectively) compared with carcasses with edible livers. All abnormalities except telangiectasis reduced LM area. Less 12th-rib s.c. fat was observed for carcasses with A−, A, A+, A+AD, and CHF abnormalities compared with car- casses with edible livers. As liver abscess severity increased compared with edible livers, carcass value diminished and frequency of carcasses railed off line (removed from the production line) increased, particularly for A+AD (4.2%), A+OP (9.7%), and A+AD/OP (11.9%). Based on analysis of this large database, liver abnormalities, especially severely abscessed and CHF outcomes, greatly affect HCW. These results indicate control of liver abscesses, and understand- ing the development of CHF, is important to prevent loss- es in carcass value.