Behavioural patterns of cows housed in two different typologies of compost-bedded pack barns

The compost-bedded pack barn (CBP) is an innovative housing technique which has the improvement of animal welfare as main objective. A comparative study of the behaviour of Holstein-Friesian dairy cows housed in two different compost-bedded pack barns located in the State of Minas Gerais (Brazil) was carried out during the winter season. One barn (CBP A) is closed and applies a wind tunnel ventilation (negative pressure). A second barn (CBP B) is open with natural ventilation, without curtains on the sides, and has fans placed in the resting area. Infrared video cameras were installed in the two barns to allow continuous and simultaneous monitoring of cows’ behaviour. Air temperature and relative humidity inside the barns were monitored continuously and Temperature-Humidity Index was consequently calculated. The results show that the cows housed in the closed barn, with forced ventilation (CBP A), were in good thermal conditions, which were fairly constant, while in the open barn (CBP B) the internal microclimatic conditions were more subject to outside climatic conditions. A close relationship was found between the trend of air temperature and relative humidity inside the facilities and the behaviour of the cows. The number of cows at rest, in CBP B, decreased as the THI value rose. In CBP A, the behaviour of the cows in relation to THI was much more constant.