title: A new modified live porcine reproductive and respiratory syndrome vaccine improves growth performance in pigs under field conditions.
abstract: The change in growth performance resulting from a new modified live porcine reproductive and respiratory syndrome (PRRS) vaccine was evaluated under field conditions for registration with the government as guided by the Republic of Korea's Animal and Plant Quarantine Agency. Three farms were selected based on their history of PRRS-associated respiratory diseases. On each farm, a total of 45 3-week-old pigs were randomly allocated to one of two treatment groups, (i) vaccinated (n = 25) or (ii) control (n = 20) animals. A new modified live PRRSV vaccine increased market weight by 1.26 kg/pig (104.71 kg versus 103.45 kg; P < 0.05) and decreased mortality by 17% (1.33% versus 18.33%; P < 0.05). Pathological examination indicated that vaccination effectively reduced microscopic lung lesions compared with control animals on the 3 farms. Thus, the new modified live PRRS vaccine improved growth performance and decreased mortality and lung lesions when evaluated under field conditions.
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
authors: Changhoon
authors: C
authors: Park
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
authors: Hwi Won
authors: HW
authors: Seo
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
authors: Ikjae
authors: I
authors: Kang
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
authors: Jiwoon
authors: J
authors: Jeong
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
authors: Kyuhyung
authors: K
authors: Choi
authors: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea swine@snu.ac.kr.
authors: Chanhee
authors: C
authors: Chae
mesh_terms: D000818:Animals; D001835:Body Weight; D006651:Histocytochemistry; D008168:Lung / Q000473:pathology; D008853:Microscopy; D008969:Molecular Sequence Data; D019318:Porcine Reproductive and Respiratory Syndrome / Q000473:pathology / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D012367:RNA, Viral / Q000235:genetics; D056910:Republic of Korea; D017422:Sequence Analysis, DNA; D016019:Survival Analysis; D013552:Swine; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines