This study is part of our internal R&D project aimed at better understanding neonatal diarrhea, to allow better management of this problem with serious consequences both for the health of piglets and for the technical and economic performance of farms. The objective of this case-control study was to assess whether the microbiological quality of the unfermented soup distributed to sows was associated with the presence of recurrent neonatal diarrhea in the herd. Our study suggests that the higher the counts of total coliforms, enterococci and yeasts in soup fed to sows, the greater the likelihood of observing neonatal diarrhea in the flock. In addition, if the two microbiological criteria, total coliforms and yeasts are simultaneously degraded, the probability of observing neonatal diarrhea is maximum. This study therefore obliges us to systematically integrate an analysis of the soups distributed to sows in our diagnosis of neonatal diarrhea.

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.