Ambience of dairy cattle raised on low profile cross ventilation barn considering different animal categories and work shifts

The objective of this reseach was to evaluate the Low Profile Cross Ventilation (LPCV) system’s microclimate in order to observe dairy cattle thermal comfort, by means of physiological indicators on different animal categories and working shifts. This project was conducted during fall in the State of São Paulo. For the microclimatic evaluation the air temperature, relative humidity and internal/external specific enthalpy were recorded by two dataloggers for 30 minutes intervals for 21 days. The physiological parameters (surface temperature, rectal temperature and respiratory frequency) were measured from 28 cows from different productive categories and working shifts. The experimental design was completely randomized in the 3x2 factorial scheme, including 9 repetitions. It was concluded that the Low Profile Cross Ventilation (LPCV) barn during fall showed efficiency for controlling the environment for the differents animal categories and work shifts studied, where all dairy cows were within the range of values for their thermal comfort.