Age dynamics of swine nematode invasions on Estonian pig farms
2002
Maegi, E. | Sahk, M. (Estonian Agricultural University, Tartu (Estonia). Faculty of Veterinary Medicine)
The purpose of this work was to explain the spread of roundworm invasions on Estonian large pig farms. The second aim was to investigate the dependence of invasion level from pig age in swine populations. The results of laboratorial analyses of several pig populations have been displayed. On the basis of the results of our observations can be concluded, that the main digestive tract parasites in swine are Ascaris suum and Oesophagostomum spp. roundworms. Invasions caused by Strongyloides ransomi could be detected only in a few swine populations and they were directly connected with age of pigs: high extensity of invasion was observed up to 4th months of age, after that the invasion extent diminished to 1 per cent in breeding sows. trichocephalus suis invasions with low densities were registered rarely as natural disease foci. Age dynamics has been detected by Ascaris suum invasions: extensity of the disease rose up to six months and after that spontaneous recovery was observed. Reinvasions were not determined because of developing immunity of older pigs. Age dynamics developed as well as in Oesophagostomum spp. invasions: extensity of invasion occurred to be in correlation with swine age. Invasions of breeding sows indicated the absence of immunity
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