• A cross-sectional survey on respiratory disease in a cohort of Irish pig farms

      Rodrigues da Costa, Maria; Fitzgerald, Rose Mary; Manzanilla, Edgar Garcia; O’Shea, Helen; Moriarty, John; McElroy, Máire C.; Leonard, Finola Catherine; Department of Agriculture, Food and the Marine; Teagasc Walsh Scholarship; 14/5/832 (Springer Science and Business Media LLC, 2020-11-21)
      Background Respiratory disease is one of the most important factors impacting pig production worldwide. There is no available information on the prevalence of key pathogens implicated in Irish pig production. The objective of this study was to describe the prevalence of pleurisy, pneumonia, lung abscesses, pericarditis and liver milk spots in finisher pigs of a cohort of Irish pig farms, and to describe the seroprevalence of: influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSv), Mycoplasma hyopneumoniae (Mhyo) and Actinobacillus pleuropneumoniae (APP). Results In brief, 56 farrow-to-finish farms (29% of the Irish breeding herd) were enrolled in the study in 2017. Data on lungs, heart, and liver lesions were assessed for each farm at slaughter. An average of 417 (range 129–1154) plucks per farm were assessed for pleurisy, pneumonia, lung abscesses, pericarditis, and liver milk spots. Blood samples from 32 finisher pigs were collected at slaughter for each farm. The observed prevalence of pleurisy and pneumonia was one of the lowest reported in similar studies in Europe (13 and 11% estimated average within farm, respectively). Pleurisy lesions were mostly moderate and severe. Pneumonia lesions affected a low level of lung surface (5.8%). Prevalence of pericarditis was mid-high (8%) and the prevalence of liver milk spots was high, with an average of 29% of the livers affected. For serology, 78.6% of the farms were positive for IAV, 50% were positive for PRRSv, 71.4% were positive for Mhyo, and 98.2% were positive for APP. Influenza virus was the main pathogen associated with pleurisy (P < 0.001) and Mhyo was the main pathogen associated with pneumonia (P < 0.001) and pericarditis (P = 0.024). Conclusions Farms affected with pleurisy had moderate to severe lesions. Farms affected with pneumonia had mild lesions, which could be the effect of the generalised use of Mhyo vaccination in piglets. The seroprevalence of IAV, PRRSv, Mhyo and APP in the present study sample is similar to or lower than in other European countries. Further research on the PRRSv and APP strains circulating in Ireland is necessary to support the design of national or regional control plans.
    • Estimating the Effect of Respiratory Disease on Production Performance in Farrow-to-Finish Pig Farms

      Costa, Maria Rodrigues da; Rovira, Albert; Torremorell, Montserrat; Fitzgerald, Rose Mary; Gasa, Josep; O’Shea, Helen; Manzanilla, Edgar Garcia; Teagasc Walsh Fellowship Programme; Department of Agriculture, Food and the Marine; PathSurvPig 14/S/832 (Research Square, 2020-05-22)
      Background Respiratory disease is one of the most important factors impacting pig production worldwide. However, the literature highlights the multitude of confounding factors complicating the clear attribution of growth impairment to respiratory disease, and the extrapolation of the effects of respiratory disease to a wider population has not been thoroughly researched. The objective of this study was to estimate the impact of respiratory disease on production performance in a subset of 56 Irish farrow-to- nish pig farms. Proxies for respiratory disease status such as serology for four major pathogens (inuenza A virus, porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae ), slaughter checks (pleurisy, pneumonia, lung abscesses, pericarditis and liver milk spots) and vaccination information were used as predictors for production performance. Results The models to estimate production performance from serology, slaughter checks, and vaccination were able to explain the variability of weaner and nisher mortality by 26 and 20%, respectively, and average daily feed intake (ADFI), average daily gain (ADG) and age at slaughter by 47, 40 and 41%, respectively. Feed conversion ratio and sow performance were not explained by the studied predictors. Conclusions The models tted, especially those for ADFI, ADG and age at slaughter, emphasize the usefulness of sourcing information at different levels to understand the impact of farm health status on pig performance, and highlight the impact of respiratory disease on production performance.