Monitor outcomes to ensure long-term PRRS control success. Track diagnostic results and pig performance data across sow, grow-finish, and whole production systems to detect low-level virus circulation, guide decisions, and move herds toward stable or negative status.
The Guilty Gilt Guide was written with a clear objective – to maximize the whole-herd performance of pig populations by helping gilts to reach their full reproductive potential and produce healthy pigs that reach their full genetic potential during grow-finish.
The open reading frames (ORF)5 represents approximately 4% of the porcine repro- ductive and respiratory syndrome virus (PRRSV)-2 genome (whole-PRRSV) and is often determined by the Sanger technique, which rarely detects >1 PRRSV strain if present in the sample.
Porcine reproductive and respiratory syndrome virus (PRRSV) is an important swine pathogen affecting the global swine industry.
In spring 2015, an outbreak of porcine reproductive and respiratory syndrome (PRRS) struck Lower Austria caused by a PRRS virus (PRRSV) strain spreading rapidly among both previously PRRSV negative and vaccinated pig herds. This case report describes the first well-documented emergence of the PRRSV strain responsible for this outbreak.
A PRRSV seronegative piglet-producing farm in Lower Austria encountered losses in foetuses and suckling piglets of up to 90 %; clinical signs in sows and nursery piglets included fever and reduced feed intake. Additionally, high percentages of repeat breeders and losses of up to 40 % in nursery piglets occurred. An infection with PRRSV was suggested by the detection of antibodies by enzyme linked immunosorbent assay and confirmed by quantitative real time PCR. The underlying PRRSV strain, termed AUT15-33, was isolated by passage on porcine alveolar macrophages, partially sequenced (ORF2-7) and grouped as PRRSV-1, subtype 1. In phylogenetic analysis of the genome region coding for the structural proteins, ORF2-7, AUT15-33 clustered with Belgian strains but identities were as low as 88 %. In contrast, analysis of ORF7 sequences revealed a close relationship to Croatian strains from 2012 with an identity of 94 – 95 %.
Control of porcine reproductive and respiratory syndrome virus (PRRSV) remains problematic, and economic studies have uniformly shown that PRRSV inflicts major losses on swine health and productivity. A fuller picture of PRRSV genetic relationships and evolutionary origins may be facilitated by whole genome analyses and comparisons of multiple protein coding regions, including the polymerase gene, which is widely used in RNA viral evolutionary analyses. PRRSV viral infection can be divided into three distinct stages: acute infection, persistence, and extinction. Acute infection follows exposure and is characterized by rapid spread to primary sites of replication in lung and lymphoid tissues. PRRSV markedly alters innate immunity and inflammatory and immunoregulatory cytokines in a strain- specific manner. Infection with PRRSV induces immunity that eventually controls the initial infection, eliminates the virus, and establishes memory that is variably protective against future infection.
Standardized terminology for the porcine reproductive and respiratory syndrome virus (PRRSV) status of swine herds is necessary to facilitate communication between veterinarians, swine producers, genetic companies, and other industry participants. It is also required for implementation of regional and national efforts towards PRRSV control and elimination. The purpose of this paper is to provide a herd classification system for describing the PRRSV status of herds, based upon a set of definitions reflecting the biology and ecology of PRRSV. The herd classification system was developed by a definitions committee formed jointly by the American Association of Swine Veterinarians (AASV) and the United States Department of Agriculture PRRS-Coordinated Agricultural Project, and was approved by the AASV Board of Directors on March 9, 2010. The committee included veterinarians from private practice and industry, researchers, and representatives from AASV and the National Pork Board.
Breeding herds, with or without growing pigs on the same premises, are categorized as Positive Unstable (Category I), Positive Stable (Category II), Provisional Negative (Category III), or Negative (Category IV) on the basis of herd shedding and exposure status. Growing-pig herds are categorized as Positive or Negative. Recommended testing procedures and decision rules for herd classification are detailed.
Processing fluids (PF), the serosanguinous fluid recovered from piglet castration and tail docking, were used for porcine reproductive and respiratory syndrome virus (PRRSV) infection assessment. Processing fluid samples from four breed-to-wean herds were compared with standard sampling protocols, demonstrating PRRSV RNA detection in PF at greater frequency than standard schemes.