A biological network describing infection with Mycoplasma hyopneumoniae in swine herds.

We have made a biological model based on a Bayesian network for risk factors for infection with Mycoplasma hyopneumoniae (Mycoplasma) in slaughter pigs; prevalence of infection is based on veterinary examinations. The model is a probabilistic/stochastic determination based on the inherent biological uncertainty of the severity of infection with Mycoplasma and the derived stochastic effects on productivity for the herd. The conditional probabilities in the Bayesian network are based on published studies and expert opinions. We used the model to calculate how the risk factors and our evidence about the herd influenced our view on the severity of Mycoplasma, and how our view changed when we had more veterinary evidence. We also show how one can use the model to deal with conflicting examinations.