PRRSV-1 Stabilization: A Way to Reduce Antibiotic Usage

This study reports an investigation into 19 French farrow-to-finish farms that successfully implemented the porcine reproductive and respiratory syndrome virus type 1 (PRRSV-1) stabilization protocol between 2007 and 2019. One year before (P1) and one year after (P2) the introduction of this protocol, the antibiotic consumptions (expressed in mg/PCU and ALEA) were compared for each farm. The difference between P1 and P2 was also calculated in percentages. The transition from P1 to P2 revealed that the higher the consumption levels were in P1, the greater the antibiotic reduction in P2. These results emphasize how stability against PRRSV-1 seems to reduce antibiotic usage, particularly in farms with a high level of consumption.

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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 amodified live vaccine in five positive stable herds with different management practices including external and internal biosecurity measures.

Data concerning PRRSV-1 vaccine virus strains dissemination within vaccinated sow herdsare scarce. However, it is a big concern for swine practitioners when designing the PRRSV diagnostics strategy in vaccinated farms. At the same time, the possibility of vaccine virus transmission from sows to their offspring is important to have in mind in order to limit the risk of recombination between different PPRSV-1 modified live virus vaccine (MLV1) when both sows and piglets have to be vaccinated. This study was conducted in five PRRSV-stable breeding herds. The selected farms presented different characteristics regarding production parameters and biosecurity management practices in order to be, as much as possible, representative of French swine production herds. In four different batches following a sow mass vaccination with a PRRSV-1 modified live virus vaccine (ReproCyc® PRRS EU, Boehringer Ingelheim, Ingelheim, Germany), we failed to detect the vaccine virus in due-to-wean piglets in all of the herds. This should mean that the dissemination of the vaccinal strain is a rare event, even just after a sow vaccination, at least for the vaccine tested in our study.

Neonatal diarrhea

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.

This retrospective study described the aetiologies of neonatal diarrhoea cases and their associations with histological findings. A total of 106 diarrhoeic neonatal piglets were selected. Cultures, MALDI typings, PCRs and evaluation of intestinal lesions were performed. A total of 51 cases (48.1%) were positive for only one pathogen and 54 (50.9%) were positive for more than one pathogen. Clostridium perfringens type A was the most frequently detected pathogen (61.3%), followed by Enterococcus hirae (43.4%), rotavirus type A (38.7%), rotavirus type C (11.3%) and enterotoxigenic Escherichia coli (3.8%). Only lesions in the small intestine were correlated with detected pathogens. The detection of rotavirus was associated with an increased probability of observing villous atrophy (p < 0.001), crypt hyperplasia (p = 0.01) and leucocyte necrosis in the lamina propria (p = 0.05). The detection of Clostridium perfringens type A was associated with an increased probability of observing bacilli in close proximity to the mucosa (p < 0.001) and a decreased probability of observing epithelial necrosis (p = 0.04). Detection of Enterococcus hirae was associated with an increased probability of observing enteroadherent cocci (p < 0.001). Multivariate regression logistic models revealed that epithelial necrosis was more likely to occur in Enterococcus hirae-positive piglets (p < 0.02) and neutrophilic infiltrate was more likely to occur in Clostridium perfringens type A– and Enterococcus hirae-positive piglets (p = 0.04 and p = 0.02, respectively).

Contact voltages < 0.5 V in feeders and drinkers influence the behaviour and oxidative status of piglets

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.

The aim of this study was to evaluate the impact of stray voltages < 0.5V in pig housing on the behaviour of piglets and health and welfare biomarkers after weaning. For this study, two consecutive batches of 860 pigs weaned at 28 days were divided between two rooms of 12 pens, each with 33-36 piglets. In each pen, the difference in electrical potential between the floor and each drinker and feeder was measured every two weeks. Piglets were divided into four groups as a function of the voltage in drinkers and feeders. Behaviour was observed by scan sampling twice a week for seven weeks. It showed that piglets exposed to high-voltage drinkers (> 125 mV) spent less time standing inactive (P = 0.05) and more time orally manipulating pen mates (P = 0.003). Piglets exposed to high-voltage feeders (> 50 mV) spent less time sleeping (P = 0.02). They also spent more time nosing and being aggressive to pen mates but these effects were influenced by the voltages in drinkers (P = 0.03 and 0.02, respectively). Hydroperoxides concentration tended to be higher in piglets exposed to high voltages in both drinkers and feeders (P = 0.06). Our results suggest that the presence of stray currents in housing might influence the behaviour and oxidative status of piglets in post-weaning facilities