Scientific publications

Porcine ear necrosis may have social causes among other risk factors already described.

This study reports an investigation into farrow-to-finish farms that successfully implemented the porcine reproductive and respiratory syndrome virus type 1 stabilization protocol.

The purpose of this study was to describe vaccinal strain detection using qPCR on blood samples collected from due-to-wean piglets after a mass vaccination of their dams with a modified live vaccine in five positive stable herds with different management practices including external and internal biosecurity measures.

Morbidity, mortality and loss of productivity due to enteric diseases in neonatal piglets are still major issues worldwide. The aim of our retrospective study was to describe the aetiologies of neonatal diarrhoea cases in a French veterinary pig practice and to determine their associations with histological findings in the small and large intestine

Stray currents of low voltage in drinkers and feeders in post-weaning units affect piglets’ behaviour and oxidative status, suggesting that stray currents might induce a physiological stress for piglets.

This study was carried out for an external R&D service for a pharmaceutical laboratory. The objective was twofold. First, for our client, this study made it possible to compare the effectiveness of two of these vaccines for the prevention of enzootic pneumonia in breeding based on clinical criteria, technical performance (ADG, mortality) and injury criteria.

Changes in haematological values occur during the reproductive cycle. In veterinary swine practice, haematological reference intervals for this period are scarce. Over past decades, there has been a remarkable increase in reproductive prolificacy, possibly making previously established haematological reference intervals for sows outdated.
The aim of this study was to provide updated haematological reference intervals for sows at endgestation, to study the influence of parity on those haematological parameters and to evaluate the impact of haemoglobin levels on production performance.

Microbiota play a significant role in host health and metabolism and the swine digestive tract provides the appropriate habitat for a huge number of microbial species. The newborn piglet gut rapidly acquires its microflora by contact with its dam and surrounding environment but a transfer might also occur during gestation.

Counts of yeast, total coliforms (37°C) and Enterococcus spp. (37°C) appeared as relevant criteria to assess whether liquid feed consumed by sows is at risk of neonatal diarrhoea occurrence

Mycoplasma suis was detected in all 10 farms and in all parities, suggesting that M. suis infection is probably widespread and enzootic. Nevertheless, in our study, based on recorded clinical signs and production, haematological and biochemical parameters, we could not demonstrate a significant impact of M. suis infection on health status and production performances of sow herds, except an increase in stillbirth rate in gilts.

Processing fluids and blood samples at weaning were collected in four consecutive batches born after a booster sow mass MLV vaccination. We failed to detect PRRSV by qPCR on PF and BS collected in a positive-stable breeding herd after vaccination with a modified live vaccine.

In our study, the comparison of qPCR results with microscopic investigation of Giemsa-stained blood smears revealed a lower sensitivity of the microscopic method: only 33 out of 102 qPCR positive blood samples were microscopically positive (M. suis visualized). No relationship between mean qPCR loads and microscopic observation was observed.

Pooled OF sampling is representative at litter level if collection is successful (> 2 ml of fluids collected). In order to improve the success rate of collection, pre-exposing the piglets with a rope one day prior to sampling is effective

In Europe, modified live vaccines (MLV) are commonly used to control porcine reproductive and respiratory syndrome virus (PRRSV) infection. However, they have been associated with safety issues such as reversion to virulence induced by mutation and/or recombination. On a French pig farm, we identified a field recombinant strain derived from two PRRSV-1 MLV.

We showed that MDNAs impair vaccine efficacy against PRRSV both in inoculated and contact piglets, probably by reducing vaccine replication.
IFNa may also interfere with PRRSV vaccination. These new data could help improving vaccination protocols.

The rate of detection of PRRSV-1 was about the same in OF and blood samples. Virus sequencing, if required, should be performed on individual serum samples but we failed to sequence virus from OF (higher Ct).

Evaluation of porcine reproductive and respiratory syndrome stabilization protocols in 23 French Farrow-to-finish farms located in a high-density swine area

This study reported that reliable results may be obtainable through transverse sampling (herd profiling), where several batches of different ages are sampled concurrently. This has advantages in time and labour costs over longitudinal sampling procedures, where animals are repeatedly sampled at different time points.