The Costly Health Effects of Heat Stress March 16, 2023 As the hot summer months are approaching, a common topic you’ll hear discussed throughout the dairy industry is heat stress and heat abatement–with good reason. Heat stress is problematic to any dairy producer as it results in lower milk production, decreased milk quality, reproduction issues, overall cow health issues, and sometimes cow loss. Therefore, heat stress is costly. What is Heat Stress? Heat stress is any combination of temperature, humidity, radiation, and wind-producing conditions higher than the animal’s thermal neutral zone, causing the animal’s body temperature to begin to rise. It’s important to understand what heat stress is, so you can help to prevent it. Peter Manneke, the Territory Sales Manager for Europe, Middle East & Africa for VES-Artex, stated in a recent webinar, “Cow comfort, especially ventilation and cooling, is not a luxury. It is vital for herd health. It saves money. We can measure what it can do and give you a prediction of how much money you can save.” What are the Visual Behaviors of Heat Stress? Some common visual behaviors that cows may show when under heat stress are listed below: Perching: When the cow stands with her front feet in the stall and back feet in the alley. Alley standing: When the cow stands in the alley to be cooled from soakers and other cooling resources. Manure splatter on legs: When the cow attempts to cool herself with cool mud and manure. Standing in water: When the cow attempts to cool herself by standing in her water source. Bunching: When a cow naturally responds to stress by grouping together in an attempt to obtain the same resource (wind, water, etc.). Many of these behaviors, along with heat stress, may lead to serious health effects in your herd. What are the Health Effects of Heat Stress? Cows may suffer from several health effects of heat stress, including issues with reproduction, transition, and their udder. While one of the most costly effects of heat stress on a farm is cow loss, there are several other effects that are costly as well. While the list below is long, it still doesn’t include all of the health effects of heat stress: Reduction of rumination Reduction of the buffer effect from the saliva Difficult mobility Reduction of fat level in milk Increased embryo failure and abortion rates Uneven cow flow, especially in transition facilities Reduced dry matter intake Reduced colostrum quality and value Low birth weight due to shorter gestation Increased DA rates Increased ketosis Increased Metritis Increased retained placenta Increased udder edema Increased prevalence of manure slurry in alleys Increased lower leg contamination and udder splash Higher bacterial loads for parlor prep to remove Increased prevalence of mastitis Heat stress is costly if not prevented. Fortunately, there are many ways to prepare your farm in order to prevent heat stress. VES-Artex’s integrated barn system, DairyBOS, allows producers to automate, monitor, and make real-time adjustments to their ventilation, lighting, and cooling systems. By implementing an efficient system to cool and ventilate your herd’s environment, you decrease heat stress and its costly health and production effects.