Study on the kinetics of antibodies against Mycoplasma hyopneumoniae in sows at time of parturition.

摘要

The aim of this study is to describe the kinetic of serum antibody concentrations against Mycoplasma hyopneumoniae postpartum (p. p.) in vaccinated and non-vaccinated sows. The characterisation of antibody kinetics at the time of parturition was investigated to estimate whether the sampling of sows immediately after parturition is a prerequisite or can be replaced by sampling at a later date. Serological examination in sows shortly before parturition is often conducted in studies focusing on the induction of maternal antibodies by vaccination, but at this time this is very stressful for the animals. A time displacement of 3 to 5 days would be preferred if the antibody concentration remains at a constant level during this time period. Material and methods: The study was performed on 47 sows in a herd endemically infected with M. hyopneumoniae. Sows from the vaccinated group received M. hyopneumoniae 6 and 3 weeks before parturition; sows of the control group were treated with physiological saline solution. Blood samples were collected from all sows 6 and 3 weeks ante partum (a. p.) and on day 1, 3 and 5 p. p. ELISA was performed to detect antibodies against M. hyopneumoniae. Results: Within the period from 6 to 3 weeks a. p. vaccination with vaccine M. hyopneumoniae induced a significant increase in serum antibody concentration that remained constant until parturition. Serum antibody concentration in non-vaccinated sows decreased within the period from 3 weeks a. p. to 1 day p. p. According to vaccination history different antibody concentrations were detected on day 1 p. p. The comparison of S/P-values on day 1 and 3 p. p. showed no significant differences within the group of vaccinated or non-vaccinated sows while day 1 and day 5 values were significantly different. Conclusion: Concentration of serum antibodies against M. hyopneumoniae remained nearly constant during the first three days after parturition. Consequently, blood sampling, as often practiced immediately after parturition to investigate the induction of maternal antibodies by vaccination, can be postponed until day 2 or 3 p. p.