Effective Heat Stress Solutions for Dairy Cattle in Summer

By Blake Jackson

Heat stress in dairy cattle during the summer negatively impacts all animals on the farm. Lactating cows often experience reduced milk production, fluctuating fat and protein content, and lower dry matter intake. Dry cows under heat stress may have shorter gestation, more challenging transitions, and decreased performance in the next lactation.

Calves and heifers can have slower growth and increased disease risk. Effective heat abatement through shade, air, and water is essential for all animals, regardless of age or stage.

Shades can be provided in pastures using trees or structures. Portable structures, often made of steel frames with corrugated steel or shade cloth, allow rotational grazing flexibility. Shade reduces aggressive behaviors, encourages grazing, rumination, and resting, and can increase milk production.

Structures should be inspected for damage after summer and winter, especially shade cloths prone to tearing or snow damage. In barns, shading requires careful consideration of sun angles and airflow. Movable shade cloths can block sunlight without restricting ventilation.

Proper air circulation is critical for barn-housed cattle. Fans and tunnel ventilation help cool cows if properly maintained. Cleaning fan blades, motors, belts, and checking angles ensures adequate airflow. Wind speeds should reach at least 5 mph at cow lying and standing levels, with adjustments made as needed.

Water is the most important form of heat abatement. Cold water helps cows regulate body temperature, and tanks should be shaded and provide 2.5-3.5 inches of space per animal. Waterers must refill quickly, remain clean, and may require guardrails if cows stand in them.

Sprinklers or soakers can also reduce heat stress, improve dry matter intake, and boost milk production. Lines and heads should be checked for debris or leaks.

Heat abatement improves welfare and performance only if it is maintained and functional. Regular spring inspections and adjustments for shade, air, and water systems are key for summer dairy management.

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