Spatial distribution of bed variables and animal welfare indicators in different typologies of compost-bedded pack barn

The challenge for the milk industry is to maintain the focus on efficient transformations that lead to increasingly significant production results. In this sense, in confinement systems for dairy cattle, there has been a constant search for more modern and economically viable techniques that provide greater welfare and comfort to the animals, while allowing for the preservation of the environment. Among the housing options, the Compost-Bedded Pack Barn (CBP) system has shown promise for the climatic conditions in Brazil. This research aimed to compare the bedding quality and the health of the herd of cows housed in CBP with different constructive forms: CBP with closed sides and tunnel ventilation system and b) CBP with open sides and low-volume, high-speed fans. For the assessment of bedding quality, the temperature and humidity were measured. The variables used to assess animal welfare were: hygiene score and locomotion score. Based on the experimental results, it was observed that the average values of the surface temperature of the bedding were slightly higher in the open compost barn compared to closed CBP, with adequate comfort conditions for the animals to lie down. The average temperature values of the bedding at 20 cm depth in both systems were slightly lower than the lower limits recommended. The closed CBP had a significant increase in moisture content compared to the open CBP. The average values of hygiene and locomotion scores in both systems did not present statistical differences between the facilities analyzed. In general, cows housed in both evaluated systems had an adequate hygiene score and locomotion score, and the incidence of lameness was not common. It is possible, based on the obtained results, to trace strategies for the improvement in the constructive typology of the building, in the used ventilation system.