Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

The study was carried out with two groups of 100 Holstein cows each, mid-lactation, raised in a freestall barn of a commercial dairy farm located in So Pedro city, State of So Paulo. During the trial the microclimate parameters recorded hourly from 8:00 AM to 6:00 PM inside and outside the barn were: black globe temperature, dry bulb temperature, relative humidity and air velocity. The freestall barn had four waterers with enough water flow to supply all the animals ad libitum. An additional waterer was at the exit of the milking parlor. Average water intake of each group was measured using water flowmeter. The data was used to quantify the lactating cows water intake, to determine waterer frequency of use, the time cows spent drinking water, eating, standing or lying down, rumination and resting time and relating it to the ambient temperature humidity index and black globe temperature. The results verified that as thermal stress had a great influence on animal behavior. The thermal stress increased water intake, frequency of waterer use, and increased the time cows spent drinking water.