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Report no. 589Henrik Wachmann Sven Erik Jorsal 13.03.2003
Removal of the growth promoter tylosine from finisher feed: effect on Lawsonia, Salmonella and texture of manure
Abstract
The trial was carried out in six herds and comprised the
following groups:
Dry feeding was used in five herds and liquid feeding was used in one herd. There were 93 blocks, and a total of approx. 4,300 pigs/group. The trial comprised pigs in the average growth interval from 31 to 101 kg. The only difference between the diets in a herd was whether 20 mg/kg tylosine had been added. Examinations for Lawsonia in the manure in the five herds using dry feeding showed that generally the prevalence of Lawsonia was lower in pigs given feed containing tylosine compared with pigs that were not given tylosine in the feed. In the herd using liquid feed there was no correlation between the prevalence of Lawsonia and tylosine in the feed. Examinations of blood samples showed no effects of removing tylosine as growth promoter on the prevalence of Salmonella. However, only two of the six herds had a Salmonella status above level 1 during the trial period. The effect of tylosine on the manure texture depended on the herd, thus making it impossible to make an unequivocal conclusion. None of the herds had significant problems with diarrhoea. On the basis of the results of the trial, it can generally be concluded that removal of the growth promoter tylosine from finisher feed may in some herds have caused an increased prevalence of Lawsonia in the manure. However, the results do not indicate that the increased prevalence of Lawsonia resulted in significant problems with diarrhoea in finishers. The prevalence of Salmonella in the finisher production was probably not affected by removal of tylosine from the finisher feed. |
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