LAUSR

The objective of this study was to identify biosecurity practices associated negative status (-) for Mycoplasma hyopneumoniae (MHYO), porcine reproductive and respiratory syndrome virus (PRRSv), and swine influenza virus (SIV) in pig farms. Biosecurity practices were assessed using the Biocheck.UGentTM questionnaire in 54 Irish farrow-to-finish pig farms. For each farm, a batch of pigs was observed at slaughter and blood samples were collected from 32 randomly selected pigs per farm at exsanguination. Serology analysis was performed using IDEXX ELISA kits and farms were classified with either positive or negative status for each of the respiratory diseases. Data were analysed using univariable logistic regression in PROC GENMOD of SAS v9.4. Results are presented as odds ratios (OR) and their associated 95% confidence interval (CI). Regularly cleaning materials used for disease treatment between litters (OR=8.2, CI=0.97-69.87), cleaning driving boards (OR=5.5, CI=1.07-28.20) and a maximal density of 3 pigs/m2 in the nursery were associated (P< 0.05) with an increased likelihood of MHYO(-). The feeding company meeting special hygienic requirements (OR=3.84, CI=1.14-12.95) and a strict all-in-all-out management in each finishing room (OR=3.84, CI=1.14-12.95) were associated (P< 0.05) with an increased likelihood of PRRSv(-). However, having disinfection baths between each room (OR=0.20, CI=0.06-0.68) and footbaths installed at the entrance of each building (OR=0.15, CI=0.04-0.52) were associated (P< 0.05) with decreased likelihood of PRRSv(-). Only allowing visitors’ access to the farm from a hygiene lock (OR=4.41, CI=1.04-18.71), and minimal piglet handling during lactation were associated with an increased likelihood of SIV(-) (P< 0.05). Results indicate that biosecurity practices regarding cleaning and disinfection and animal management are the most associated with a negative farm status for respiratory disease. It is possible that the biosecurity practices implemented in farms with lower likelihood for negative status were applied in a more ‘reactionary’ than ‘preventive’ manner.