Lesions in finished early born lambs in southwest England and their relationship with age at slaughter

During a 2 year prospective study of 4413 early born housed lambs, from three flocks in southwest England, 3910 (88.6%) lambs were finished and 3718 (95.1%) of these were observed at the abattoir. The identity, age, carcase and pluck abnormalities and dead weight, conformation and fat classification of each lamb were recorded. Up to 20% of lambs had at least one abnormality. Pneumonia was the most frequent lesion observed with 10-15% of the lung tissue affected in the majority of lambs. Pleurisy, pericarditis and Cysticercus ovis infection were also observed in thoracic organs. In the carcase bruising, pleurisy, arthritis and C. ovis were the most frequent causes of rejection. Livers with haemorrhagic tracts thought to be related to parasite migration were observed. Prevalent lesions at slaughter of arthritis, pleurisy and pneumonia were associated with an increase in days to slaughter. The rejections and reduced growth rate were estimated to have cost the farmers £600-1500 per annum.