Stochastic and Deterministic Analysis of Evaporative Cooling Benefits for Laying Hens

ABSTRACT Amodel for predicting layer performance as a function of inside temperature was used to determine the effects of evaporative cooling and local climatic effects on economic return. A stochastic weather model analysis was used to determine the effects of geographic location upon production with and without evaporative cooling and the effect of flock placement date. The stochastic analysis demonstrated the need to use a minimum of 50 years of replication to reasonably determine expected performance due to significant yearly variations in production response. Yearly variations were particularly large for the number of eggs produced and their distribution by size. The stochastic analysis yielded very different results than an analysis using a deterministic weather model, which has been the normal method of analysis to date. The simulation results strongly indicated that evaporative cooling can provide significant production benefits even in moderate northern climates and that flock placement date strongly affected expected returns.