Heat Stress in Cows — Cooling and Night Feeding
Combating the extreme North Indian summer (Loo). Low-cost cooling fans, sprinklers, and optimal night-time feeding protocols.
The Summer Loo and Heat Stress
During North Indian summers (May and June), temperatures often cross 45°C, accompanied by dry, hot winds (Loo). Crossbred cows (HF and Jersey) start experiencing heat stress when the Temperature-Humidity Index (THI) exceeds 68 (around 25°C). Symptoms include open-mouth panting, drooling, high rectal temperature, and a 20-30% drop in feed intake and milk yield.
Shed Cooling Systems
Install ceiling fans or air circulators to move air over the cows. Combine fans with water sprinklers or misting lines. Sprinklers should wet the cow's back for 1-2 minutes, followed by 10-15 minutes of fan cooling to evaporate the water and pull heat from the body. Avoid misting in closed, humid sheds as it creates a sauna effect; ventilation must remain high.
Altering the Feeding Schedule
Cows generate significant metabolic heat when digesting feed. During the hot afternoon, they will refuse to eat to avoid overheating. Shift 60-70% of the daily feed allowance to the cooler evening and night hours (6 PM to 6 AM). This encourages normal feed intake and keeps the rumen active when ambient temperatures are lower.
Water Availability and Electrolytes
A heat-stressed cow can drink up to 150-180 litres of water daily. Ensure clean, cool drinking water is available 24/7 under shade. Add common salt (1-2%) and sodium bicarbonate (baking soda, 1%) to the feed or water to replace electrolytes lost through drooling and sweating.
Combating heat stress requires cooling and timing. Use sprinklers and fans together, shift 70% of feeding to night hours, and keep cool drinking water available 24/7 under shade.