APPLICATION OF A STOCHASTIC DISTRIBUTED DELAY SIMULATION-MODEL TO FINANCIAL ANALYSIS OF RESPIRATORY-DISEASE IN MICHIGAN DAIRY-CATTLE

A stochastic, distributed delay simulation model was developed to cond uct economic analysis of respiratory disease in Michigan dairy cattle. This economic analysis employed non-traditional methods for estimatio n of the cost of disease, These include (1) a stochastic distributed d elay simulation model, (2) inclusion of the reduction in feed costs du e to disease, (3) measurement of the effect of risk factors on disease costs, and (4) incorporation of disease data from a randomly sampled, prospectively-monitored population of herds. This approach resulted i n an increase in the estimated cost of respiratory disease to $4604 yr (-1) from $1490 yr(-1) (as previously reported in the same herds) by c onsidering the effects of disease on growth, milk production, lost gen etic potential, and replacement costs. It is hoped that this model or some of these modelling approaches may be useful to others attempting to estimate the cost of disease and the effect of intervention strateg ies.