Fachbereiche
Influenzaviren und Lüftungsfehler - Quelle: "agrarheute Schwein"
Schwanzbeissen auch im Biobetrieb - Quelle: "agrarheute Schwein"
Gesund ist Trumpf - Quelle: "agrarheute Schwein"
Dr. Martin Pfützner, Tierärztliche Praxis am Weinberg GmbH
Background and Objectives PRRSV surveillance is of utmost importance in both negative and vaccinated swine herds, to reduce economic losses. Sampling piglets at weaning time using serum blood samples is a very common way to monitor PRRSV (Holtkamp et al. 2011). However, processing fluids are a sensitive, practical and time-effective tool to monitor PRRSV in sow herds (Vilalta et al. 2018). The aim of this study is to compare both techniques in an assumably stable breeding herd.
Material and Methods A 3.600 head sow farm with a weekly production cycle and whom are vaccinated consistently 3 times a year, was examined for PRRSV stability. Two to five day old piglets were examined by processing fluids (PF) at day of processing (ear tags, tail docking, castration) and at intervals of four weeks. The same groups were sampled by 30 blood samples at the time of weaning. Processing fluid samples and blood samples were taken in accordance to sow parities. Each parity group (1, 2-4, 5+) was represented by 10 BS and 2 PF samples, which were tested for PRRSV by RT-PCR.
Results There was no PRRSV detection in processing fluids. One pooled blood sample at third (BS3, parity 1) and two pooled blood samples at fourth point of time (BS4, parity 2-4) were PRRSV positiv. Sequencing of ORF5 revealed a 99.5% homology of used vaccine strain.
Discussion and Conclusion Due to the good sensitivity of processing fluids in detecting PRRSV, the investigated sow population can be declared as stable. On the other hand, because of the recurrent PCR positive results in some of the blood samples, the whole herd cannot be defined as stable (Holtkamp et al. 2011). Therefore blood samples could provide good information about possible lacks of the internal biosecurity measures, if processing fluids are delivering negative results.