Cows & Heat

Heat Load

To remain healthy, the cow must 'defend' the core body temperature to ensure it stays within the optmal limit. This means balancing the metabolic and the absorbed environmental heat.

A dairy cow actively manages the body heat content or ‘heat load’ that it carries within itself all the time. If the sum of metabolic heat produced internally by the cow and the heat gained from the external environment begins to exceed that lost, the cow’s heat load starts to build.

Once heat load reaches a critical point, a chain reaction of physiological changes occurs which has far reaching impacts, not only for milk production, but also for cow fertility, health and welfare.

It is important for dairy farmers to know the signs of excessive heat load such as a high breathing rate so practical strategies can be implemented promptly to help the cows cope.