Effect of Edema Disease Vaccination on Mortality and Growth Parameters in Nursery Pigs in a Shiga Toxin 2e Positive Commercial Farm.

Diseases caused by Escherichia coli are recognized as major problems in the swine industry, one of them being edema disease (ED). Importantly, the current decrease in antibiotic use may cause difficulties in controlling the disorders caused by E. coli. Therefore, this study assessed the efficacy of a commercial vaccine against ED in nursery pigs from a farm with previous history of ED. A total of 1344 pigs were monitored; half of them were randomly assigned to a vaccinated group (VG) and the other half to a non-vaccinated group (NVG). The vaccine was administered at 7 days of age. Animals received a pre-starter feed with 2500 ppm of zinc oxide (ZnO) for 2 weeks and a starter feed without ZnO for another 3 weeks. Pen-group weights were recorded at 28 (weaning), 42 (end of pre-starter phase), and 63 days of life (end of nursery phase). Death/culling rates, average daily gain (ADG), and average daily feed intake (ADFI) were calculated for each group at each phase. The overall relative risk of dying/being culled for a pig in the NVG was 5 times higher than that of the VG group but increased to 12 times higher during the starter period. ADG and ADFI were also significantly higher in the VG group for that period. Vaccination against ED significantly reduced pig losses and improved ADG and ADFI, particularly when ZnO was not used.

Diversity of influenza A viruses retrieved from respiratory disease outbreaks and subclinically infected herds in Spain (2017-2019).

The present study was aimed to assess the diversity of influenza A viruses (IAV) circulating in pig farms in the Iberian Peninsula. The study included two different situations: farms suffering respiratory disease outbreaks compatible with IAV (n = 211) and randomly selected farms without overt respiratory disease (n = 19). Initially, the presence of IAV and lineage determination was assessed by qRT-PCR using nasal swabs. IAV was confirmed in 145 outbreaks (68.7%), mostly in nurseries (53/145; 36.5%). Subtyping by RT-qPCR was possible in 94 of those cases being H1avN2hu (33.6%), H1avN1av (24.3%) and H1huN2hu (18.7%), the most common lineages. H3huN2hu and H1pdmN1pdm represented 7.5% and 6.5% of the cases, respectively. As for the randomly selected farms, 15/19 (78.9%) were positive for IAV. Again, the virus was mostly found in nurseries and H1avN2hu was the predominant lineage. Virus isolation in MDCK cells was attempted from positive cases. Sixty of the isolates were fully sequenced with Illumina MiSeq®. Within those 60 isolates, the most frequent genotypes had internal genes of avian origin, and these were D (19/60; 31.7%) and A (11/60; 18.3%), H1avN2hu and H1avN1av, respectively. In addition, seven previously unreported genotypes were identified. In two samples, more than one H or N were found and it was not possible to precisely establish their genotypes. A great diversity was observed in the phylogenetic analysis. Notably, four H3 sequences clustered with human isolates from 2004-05 (Malaysia and Denmark) that were considered uncommon in pigs. Overall, this study indicates that IAV is a very common agent in respiratory disease outbreaks in Spanish pig farms. The genetic diversity of this virus is continuously expanding with clear changes in the predominant subtypes and lineages in relatively short periods of time. The current genotyping scheme has to be enlarged to include the new genotypes that could be found in the future.

Viral and bacterial investigations on the aetiology of recurrent pig neonatal diarrhoea cases in Spain.

BACKGROUND: Neonatal diarrhoea represents a major disease problem in the early stages of animal production, increasing significantly pre-weaning mortality and piglets weaned below the target weight. Enteric diseases in newborn piglets are often of endemic presentation, but may also occur as outbreaks with high morbidity and mortality. The objective of this study was to assess the frequency of different pathogens involved in cases of recurrent neonatal diarrhoea in Spain. RESULTS: A total of 327 litters from 109 sow farms located in Spain with neonatal recurrent diarrhoea were sampled to establish a differential diagnosis against the main enteric pathogens in piglets. In total, 105 out of 109 (96.3%) case submissions were positive to one of the examined enteric organisms considered potentially pathogenic (Escherichia coli, Clostridium perfringens types A and C, Transmissible gastroenteritis virus [TGEV], Porcine epidemic diarrhoea virus [PEDV] or Rotavirus A [RVA]). Fifty-eight out of 109 (53.2%) submissions were positive for only one of these pathogens, 47 out of 109 (43.1%) were positive for more than one pathogen and, finally, 4 out of 109 (3.7%) were negative for all these agents. Escherichia coli strains were isolated from all submissions tested, but only 11 of them were classified into defined pathotypes. Clostridium perfringens type A was detected in 98 submissions (89.9%) and no C. perfringens type C was found. Regarding viruses, 47 (43.1%) submissions were positive for RVA, 4 (3.7%) for PEDV and none of them for TGEV. CONCLUSION: In conclusion, C. perfringens type A, E. coli and RVA were the main pathogens found in faeces of neonatal diarrheic piglets in Spain.