Associations between lung lesions and grade and estimated daily live weight gain in bull beef at slaughter

A total of 645 bull beef from 15 units were examined at slaughter and their lungs scored for presence and severity of consolidation and pleurisy. Data on dead weight and carcase grade were also collected. Pleurisy and consolidation were correlated within cattle and both were associated with reduced estimated daily live weight gain (EDLWG) once producer variability had been accounted for in a hierarchical model. Consolidation had a stronger statistical association with EDLWG and cattle with 3, 4, 5 or 6 consolidated lobes had a significant reduction in EDLWG of 72, 113, 123 and 202 grams respectively. Cattle had a maximum of four lobes with >50% of each lobe consolidated and those with 3 or 4 lobes with >50% affected had a reduced EDLWG or 141 and 194 grams respectively. Carcases with a higher grade were associated with a significantly faster EDLWG and had fewer consolidated lobes per carcase. We suggest that, if these associations are causal, these results highlight the potential cost of sub-clinical lung damage on both growth and carcase quality. These results may usefully be given to farmers to encourage changes in management to reduce lung damage in live cattle.