title: Reproductive parameters following a PRRS outbreak where a whole-herd PRRS MLV vaccination strategy was instituted post-outbreak.
abstract: This study assessed the effect of whole-herd porcine reproductive and respiratory syndrome (PRRS) modified-live virus (MLV) vaccination on herd-level reproductive performance, PRRS virus (PRRSV) viremia, and antibody in a subset of females in a 1,200-sow commercial herd in Thailand. Following a PRRSV outbreak, the entire herd was vaccinated with PRRS MLV twice at 3-week intervals and at 3-month intervals, thereafter. Reproductive performance data over a 3-year period were available for analysis. Serum samples were collected before and after vaccination and tested by PRRSV ELISA and reverse transcription-polymerase chain reaction. Vaccination was statistically associated with a lower abortion rate (1.4 vs. 1.6 %), farrowing rate (83.8 vs. 90.0 %), total born (10.6 vs. 11.4 piglets/litter), liveborn (10.0 vs. 10.3 piglets/litter), stillbirths (4.6 vs. 7.0 %), mummies (0.7 vs. 1.6 %), and a higher return rate (11.3 vs. 5.9 %) when compared with the period before the PRRSV outbreak. Pregnant females vaccinated during early gestation farrowed fewer liveborn and more mummies than the comparison group, whereas females vaccinated during late gestation had a lower farrowing rate. In this herd, PRRS whole-herd vaccination had neutral, positive, and negative effects on reproductive performance. Thus, the decision to implement whole-herd vaccination should be balanced between the benefits derived from reproductive performance improvements, e.g., fewer abortions, stillborn piglets, and mummified fetuses, and the effect of vaccination on pregnant females.
authors.affiliation: Department of Obstetrics, Gynecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand, 10330.
authors.forename: Em-on
authors.initials: EO
authors.lastname: Olanratmanee
authors.forename: Suparlark
authors.initials: S
authors.lastname: Nuntawan Na Ayudhya
authors.forename: Roongroje
authors.initials: R
authors.lastname: Thanawongnuwech
authors.forename: Annop
authors.initials: A
authors.lastname: Kunavongkrit
authors.forename: Padet
authors.initials: P
authors.lastname: Tummaruk
mesh_terms: D000034:Abortion, Veterinary / Q000276:immunology / Q000517:prevention & control / Q000821:virology; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D004196:Disease Outbreaks / Q000517:prevention & control / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D005313:Fetal Death / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary / Q000821:virology; D008098:Litter Size; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology / Q000517:prevention & control* / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D011247:Pregnancy; D012098:Reproduction; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D050497:Stillbirth / Q000662:veterinary; D013552:Swine; D013785:Thailand; D013997:Time Factors; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014766:Viremia / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines