Behavior of Dairy Cows in Response to Different Barn Cooling Systems

Forty-two dairy cows were subdivided in three groups of 14 cows each. Each pen of cows was provided with afeeding area, a freestall area, and an external paddock. The study was conducted in an experimental barn located inthe Po Valley of Italy. The cows were observed during summer 1995 for milk yield and quality and for their behavior(movements and residence time in the different areas of each pen) under different microclimatic conditions (temperature,relative humidity, light exposure, air speed). The feeding and freestall areas were arranged with: (1) fans in the first pen;(2) fans and misting in the second pen; and 3) the third pen was used as control. During the summer months (from June toSeptember) microclimatic conditions, milk yield, and cow position (monitored with video cameras and automatic stillcameras placed in different areas of the barn) were recorded. During the hottest period, lower milk yield reductions wererecorded for the cows housed in pens with fans or with fans and misting. This result was consistent with the behavior ofthe cows inside experimental pens that spent longer periods of resting time in the feeding and freestall areas, and showedoverall behavior similar to that observed during a cooler period. Some cows also lay in the wet dirty areas of the pens orcrowded in a well-ventilated place. The results of this study confirm the usefulness of cooling systems for cows in a warmclimate.