Antibody responses to porcine reproductive and respiratory syndrome virus, influenza A virus, and Mycoplasma hyopneumoniae from weaning to the end of the finisher stage in fourteen groups of pigs in Ontario

Abstract

BackgroundPorcine reproductive and respiratory syndrome, swine influenza, and mycoplasmal pneumonia are some of the most prevalent respiratory diseases affecting swine farm productivity in Canada.Monitoring for the prevalence of the infectious agents associated with these diseases on farm may help to improve herd-specific control strategies and to minimize the impact of disease on commercial swine farms. The objectives of this study were to investigate antibody responses to porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), and Mycoplasma hyopneumoniae ( M. hyopneumoniae ) from weaning to the end of the finisher stage on a subset of commercial swine farms in Ontario and to examine the effects of nursery diet on antibody responses. ResultsSerology found 8, 61, and 31% of pigs at weaning, 1, 31, and 22% at the end of nursery, 8, 38, and 18% at the end of grower, and 11, 48, and 25% at the end of the finisher stage tested seropositive for PRRSV, IAV, and M. hyopneumoniae, respectively. Of the groups tested for PRRSV, IAV, and M. hyopneumoniae, 3, 14, and 5 groups had > 20% of pigs that tested seropositive at least once over the course of production ("high seropositivity"). In general, seropositivity was more likely to be lower at the end of nursery compared to the other production stages for all three pathogens, and more likely to be higher for PRRSV and IAV at weaning, end of grower, and end of finisher. Pigs that were seropositive for PRRSV were more likely to be seropositive forM. hyopneumoniae (p < 0.001). Overall, pigs fed a low complexity diet during nursery were more likely to be seropositive for PRRSV (p < 0.001) and IAV (p = 0.04). ConclusionsThis study provides information regarding changes in serum antibody in pigs across different stages of production and highlights periods of vulnerability. Additionally, these findings may encourage further research into the effects of nursery diet complexity on disease susceptibility and immune response.

African Suid Genomes Provide Insights into the Local Adaptation to Diverse African Environments

“…It was noted that two genes of common warthog relevant to visual perception and nervous system development ( MEGF11 and SOX14 ) lost the associated CNEs ( supplementary table S44, Supplementary Material online). In red river hog, one CNE was lost in an intergenic region (between the genes ENSSSCG00000049953 and ENSSSCG00000051043 , supplementary table S44, Supplementary Material online), a locus reported to be associated with the immune response to a swine pneumonia etiologic agent Mycoplasma hyopneumoniae ( Raaphorst 2020 ).…”