Antibodies against Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae and influenza virus and their relationship with risk factors, clinical signs and lung lesions in pigs of farms of Brazilian one-site production system

Author(s)

Thaís Gasparini Baraldi

• Document type: Master's Dissertation
• Press: Jaboticabal. 2018-07-31.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2018-06-22
• Advisor: Luís Guilherme de Oliveira

Abstract

A study was carried out in 21 one-site production system in southeast Brazilian pig herds to assess the relationships between serological results of pathogens involved in respiratory diseases, Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae and swine influenza virus, cough index, pneumonia score and pleuritis. Sampling for serological tests were carried out at nursering, growing, finishing and slaughtered pigs, and cough examination on growing and finishing pigs. Analyses of cranio-ventral consolidation lesions (EP-like lesions) suggestive of enzootic pneumonia and pleuritis were performed at slaughter. Herd characteristics were obtained using questionnaire asked to farmers. Antibody titers to Mycoplasma hypneumoniae and swine influenza virus increased throughout the raising phases with higher prevalence in slaughtered pigs (> 40%). On the other hand Actinobacillus pleuropneumoniae presented most of herds (14/21) with no seropositive animal. Pleuritis lesions and EP-like lesions were recorded in 9.03% and 72.4% of 908 evaluated lungs, respectively. The hystopatological of EP-lung lesions reveled suppurative bronchopneumonia in almost half of lungs (48.9%). Regression analysis were conducted to identify risk factors for cough index, pleuritis, EP-like lesions, serological results. Mycoplasma hyopneumoniae seroprevalence was associated with use of all-in-all-out management in nursery pigs, Actinobacillus pleuropneumoniae seroprevalence were associated with pleuritis and the presence of cough index in growing pigs associated with swine influenza seropositivity in nursery pigs. (AU)

• FAPESP's process: 15/25318-9 - EPIDEMIOLOGICAL SURVEY OF MAIN RESPIRATORY DISEASES IN PIGS OF STATE OF SÃO PAULO
• Grantee: Thaís Gasparini Baraldi
• Support Opportunities: Scholarships in Brazil - Master