Tiamulin feed premix in the improvement of growth performance of pigs in herds severely affected with enzootic pneumonia

Four field trials were carried out to evaluate the effect of feeding tiamulin hydrogen fumarate at 20 and 30 ppm to fattening pigs over an eight week period, on farms with histories of severe, complicated, enzootic pneumonia problems. These farms had a prevalence of pigs with pneumonic lesions from 81 to 94 per cent and a range between individual batches of 69 to 96 per cent. The results of the first three trials showed that tiamulin at 30 ppm significantly improved the weight gains and feed conversion efficiency of pigs, in comparison with controls and was superior to the groups fed 20 ppm tiamulin. A further trial with tiamulin at 30 ppm and controls only, confirmed the original findings. The overall average results showed that tiamulin improved average daily gain by 33 g (4.7 per cent) and feed conversion efficiency by 0.138 (4.7 per cent). This effect did not appear to result from a reduction in the total extent of pneumonic lesions and the possible reasons for this are discussed, but in the fourth trial the number of pigs requiring parenteral treatment was noticeably reduced.