Association of bovine lung lesions at slaughter with carcass performance, value and liver-abscess severity.

The association of lung abnormalities with carcass performance was evaluated on data from 60,843 carcasses. Lung outcomes were scored for severity of consolidation (N = Normal and < 5% consolidation, 1 = 5 to 15% consolidation, 2 = 15 to 50% consolidation, 3 = > 50% consolidation) and presence of fibrin tags (N = None, M = Minor fibrin, E = Extensive fibrin). Lung consolidation had a strong and detrimental effect (P < 0.01) on hot carcass weight, with lung scores of 1, 2, and 3 resulting in 4.2, 13.2, and 29.9 kg less carcass weight compared to carcasses with normal lungs. Minor and extensive fibrin tags, independent of consolidation, also resulted in lighter carcasses (P < 0.01; 3.5 kg and 7 kg, respectively). Presence of both lung tissue consolidation and fibrin tags resulted in less (P < 0.01) 12th rib fat thickness compared to carcasses with healthy lungs. Similarly, LM area was reduced (P < 0.01) in carcasses with lung consolidation (-1.5 to -5.5 cm²) or presence of fibrin tags (-2.3 to -2.7 cm²) compared to carcasses with healthy lungs. Additionally, severity of lung consolidation and presence of fibrin tags reduced (P < 0.01) calculated yield grade values. The greatest proportion of carcasses exhibited edible livers and did not exhibit lung consolidation or fibrin tags (47.67 and 48.88%). A much lower proportion of carcasses (1.12 and 1.89%) exhibited a lung consolidation score of 3 and extensive prevalence of fibrin tags with a major abscess outcome. Within the edible, minor and major abscess category, as lung consolidation increased from normal to 3 and presence of fibrin tags increased from normal to extensive, a decrease in carcass weight (21.5 to 50.1 kg; 5.4 to 7.4 kg), LM area (3.9 to 6.3 cm²; 1.6 to 3.1 cm²), and 12^th rib fat thickness (0.02 to 0.18 cm; 0.12 to 0.30 cm) was observed. Carcasses with an edible liver and lung consolidation scores of 1, 2, and 3, were valued $17.08, $72.27, and $140.59 less than carcasses without lung consolidation based on detriment to carcass weight. This was more pronounced in carcasses exhibiting minor and major liver abscesses in addition to presence of lung consolidation, resulting in -$19.71 to -$222.71 and -$65.70 to -$394.84 less carcass value, respectfully, compared to a carcass with an edible liver and lung. These data indicate that lung and liver health is an important factor that impacts carcass performance and value, particularly carcass weight, muscling and yield grade outcomes.