By Blake Jackson
With the winter storms much of the United States just experienced, it seems crazy to be talking about heat stress in cattle. But preparation for the summer is important.
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.
Heat Abatement Recommendations for Dairy Farmers
- Provide adequate shade for all cattle-lactating cows, dry cows, heifers, and calves-using natural shade (trees) or constructed shelters.
- Ensure proper air circulation in barns by using well‑maintained fans, cross‑ventilation, or tunnel ventilation systems.
- Use sprinklers or soakers to help lower body temperature and improve dry matter intake and milk production.
- Monitor all heat-abatement systems frequently to ensure they remain functional and effective during peak heat periods.
- Perform comprehensive spring inspections for shade, air, and water systems to prepare the herd for summer heat stress.
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Categories: Pennsylvania, Livestock, Dairy Cattle