Effect of Bacterial Agents of Porcine Respiratory Disease Complex on Productive Indices and Slaughter Weight

Abstract

Porcine respiratory disease complex comprises the interaction of two or more infectious agents. The major bacterial agents involved were investigated in 115 finishing pigs at a farm in São Paulo State, Brazil: Actinobacillus pleuropneumoniae (serology, bacterial culture, and multiplex PCR), Mycoplasma hyopneumoniae (Mhyo) (nested PCR), Pasteurella multocida (multiplex PCR), Haemophilus parasuis (PCR multiplex), and Streptococcus sp. (bacterial culture). Macroscopic and microscopic lung lesions were evaluated, and zootechnical indices were recorded. Mhyo occurred in 113 animals (98.3%), seventeen of which were co-infected with Streptococcus sp. The finding of emphysematous lung was associated with significantly lower final and carcass weight at slaughter. Although vaccinated against Mhyo with an inactivated immunogen, almost 100% of the animals were infected. Mhyo infection with and without Streptococcus sp. co-infection was related to lung lesions of varying degrees and lower slaughter and carcass weight. ResumoO Complexo de Doenças Respiratórias em suínos (CDRS) compreende a interação de dois ou mais agentes infecciosos, manejo e ambiente. Os principais agentes bacterianos causadores de CDRS foram investigados em 115 suínos em fase de terminação em uma granja no Estado de São Paulo, Brasil: Actinobacillus pleuropneumoniae (sorologia por ELISA, cultivo bacteriano e PCR multiplex), Mycoplasma hyopneumoniae (Mhyo) (nested PCR), Pasteurella multocida (PCR multiplex), Haemophilus parasuis (PCR multiplex), e Streptococcus sp (cultivo bacteriano). Foram avaliadas lesões pulmonares macroscópicas e microscópicas, e impacto nos índices zootécnicos e no aproveitamento de carcaça. Houve positividade ao Mhyo em 113 animais (98,26%), destes houve infecção associada ao Streptococcus sp ao Mhyo em 14,78% (17) animais. O pulmão enfisematoso BROMBILLA, T. et al. Cienc. anim. bras., Goiânia, v.20, 1-11, e-51615, 2019 diminuiu significativamente o peso no final da terminação e o peso da carcaça. Apesar de vacinados com imunógeno inativado contra Mhyo, quase 100% dos animais estavam infectados e as lesões mais observadas foram broncopneumonia purulenta e pleurite. A infecção de Mhyo associado ou não ao Streptococcus sp causou lesões pulmonares em diferentes graus, menor peso ao abate e da carcaça.

Economic losses associated with respiratory and helminth infections in domestic pigs in Lira district, Northern Uganda

“…Reduced market value of sick animals represents indirect disease effects, which producers often encounter. Other losses result from carcass condemnations due to lung lesions or reduced carcass quality (8,9). Previous studies have shown that multiple infections increase the severity and duration of clinical disease (10,11).…”