Forecasting the prevalence of swine hepatitis E in pig farms by a grey system GM(1,1) model

In order to predict the prevalence of swine hepatitis E,the data of swine hepatitis E in Shanghai area between 2005 and 2010 were analyzed by using the grey system theory,and a grey system GM(l,l)model was established and evaluated.The results showed that the established GM(1,1) model had very good precision and could accurately simulate the prevalence of swine hepatitis E.The infection rates of swine hepatitis E in Shanghai in 2011 and 2012 forecasted by this model were 19.25%and 18.34%,respectively.