Analysis of the effects of the roofing design on heat stress in dairy cow housing

ANALYSIS OF THE EFFECTS OF THE ROOFING DESIGN ON HEAT STRESS IN DAIRY COW HOUSING By means of a mathematical model capable of predicting the internal climatic conditions of buildings for animal housing, the influence of different roofing solutions on the animal thermal behaviour has been investigated. The model considers radiative and convective heat exchange of the shield surfaces (sun load, sky heat exchange for outside surfaces, adduction for inside surfaces). Furthermore, it considers also the sun path and air temperature during the day. The types of roofing differ in geometry (shape, height, slope) and in materials (insulation). The model calculates the internal surfaces temperature and the radiative heat exchanged between this surfaces and a theoretical cow by means of the view factor numerically calculated for each building configurations. The study makes it possible to predict the animal response for the different considered solutions and to optimise the building design in different climatic conditions. The results of the application of the model in different Italian climatic areas (North and South) are finally presented and discussed.