Effect of Evaporative Cooling System on Behavior, Milk Yield, and Milk Quality of Holstein Cows in a Tropical Climate

In a tropical climate, air temperature can be stressful for Holstein cows throughout the year. This chapter's objective was to determine how the use of ventilation and fogging on a freestall barn can positively change the behavior, milk production, and milk quality of Holstein cows in all seasons. Twenty-eight lactating cows were divided into two groups: cooling group (CG) and non-cooled group (NCG). For different weather patterns throughout the year, behaviors (position, posture, and activity) were observed every 30 min during the day. Milk production was measured and milk samples were collected for analysis of protein, fat, lactose, total solids, and somatic cell count. All animals spent most of the day standing in the shade eating, ruminating, and idling regardless of the season (P<0.05). Also, animals under cooling system showed greater milk production, fat content, and higher somatic cell count (P<0.01). Provision of cooling system during the warmer months of the year proved to be efficiently increasing the feeding time, milk production, and milk quality of lactating cows.