When ambient temperature rises above a certain threshold, dairy cattle spend energy to regulate their body temperature. This reduces feed intake and, in turn, lowers milk yield and milk fat.
Signs
- A marked decrease in feed intake
- Increased respiration rate and excessive sweating
- Lower milk yield and milk-fat percentage
Shade, ventilation and access to cool water are the basic measures against heat stress. In addition, supplements enriched with minerals such as sodium bicarbonate, magnesium and potassium help maintain rumen balance, allowing the animal to get through the stress period with fewer losses.