Dairy herd investigation - Reducing heat stress in a northeastern dairy

Because digestion generates heat in cattle, cows decrease their dry-matter intake in an attempt to reduce heat stress. As a result, heat stress can cause production losses, in dairies. This column discusses the effectiveness and cost-effectiveness of modifications that were made to reduce heat stress in a dairy in Connecticut. The facilities of this dairy were typical of those found in Northeastern dairies (i.e., they were not designed to prevent heat stress). Improvements in ventilation and the installation of an evaporative cooling system (fans and sprinklers) and shade cloth caused dramatic improvements in ambient temperature for the cows. This led to significant improvements in productivity in comparison with the previous year. The results indicated that heat and humidity were no longer causing a significant loss in milk yield. The dairy probably recovered the cost of the improvements made to the facility during the first summer of use.