How important is airspeed when it comes to cooling?

Dr. Sohail Basharat (Cow-comfort/Cow -Welfare Expert ) JLU University, Giessen Germany. Recently wrote an article outlining the finding of his extensive studies into the effects of air velocity and its ability to offer cooling to dairy cows.

Key points from the article - 

• The air moving past the cow has to be cooler than the cow herself to offer cooling.
• The faster the air is moving, the greater cooling, chilling effect potential it has.
• An effective system needs to produce high-speed air.
• The higher the airspeed, the more cooling provided.
• The effectiveness of evaporative cooling is significantly impacted by airspeed.
• The effect of airspeed at 10-18°C is negligible, but at 26 -35° the cows are significantly impacted.
• High producing cows
• Higher airspeed helps cows maintain normal body temperature during exposure to heat stress that would normally cause a rise in body temperature.
• The higher the milk production and the larger the cow, the greater the effect of changing airspeed from 43fpm/0.5mph to 790 fpm/9mphLarger, heavier milking cows get more relief from airspeed.

The article states.

"The effect of air speed on rectal temperatures at 10°C and 18°C (50°F and 65°F) is negligible. However, at 26°C and 35°C (80°F and 95°F) the cows which develop the highest rectal temperatures at low velocity are cooled most by high velocity. These cows were also those with the highest production levels, indicating greater relief for higher producing cows with increased air speed. Air velocity has no effect on heat production in the "thermoneutrality" zone (5°C to 16°C) (40°F to 60°F), but at 35°C (95°F) heat production was higher at higher air velocity indicating greater milk production potential. Overall, higher air velocities enable cattle to maintain normal body temperature during exposure to heat stress that would normally cause a rise in body temperature."

You can read the full article here.The effects of air velocity at dairy cow.

Conclusions

· Airspeed matters! The faster the airspeed, the greater its cooling potential.

· Airspeed is not as critical to cooling - 10 – 18°C

· Airspeed becomes crucial when the temperature exceeds 26°C/78°F

· Airspeed of 35fpm/0.4mph to 440fpm/5mph offer little cooling relief after 18°C/64°F

· Higher producing cows produce more heat and need faster airspeed to be cooled.

Air velocity; airspeed is essential, and most systems are failing to provide a minimum airspeed of 5mph required to offer cooling over 18°C. If your looking to purchase a system or upgrade the system you have now, be sure to ask about fan spacing and effective air movement at those recommended distances. Those two questions will give you a good way to compare systems. All fans are not created equal. 

Core Cool Systems offers a unique solution that provides airspeeds of 5mph or greater and adds intelligent water cooling for the added benefit of evaporative cooling. Maintaining core body temperature and keeping cows in their thermal comfort zone regardless of shifts in ambient temperature. The system intuitively adds a timed fine mist to the high-speed air cooling to provide the best, proactive solution to managing heat stress. 

The ultra-fine droplet from the Core Cool nozzles evaporates as that fast-moving air flows past the cows. Dr. Basharat's studies show high airspeed increases the effectiveness of evaporative cooling. The evaporation of the droplet off her coat causes a chilling effect on the blood flowing just below the surface of her skin. This cooled blood is pumped towards her heat-generating engine.  Her core. This cooled blood maintains her core body temperature, keeping her feeling consistently cool.  She doesn't even notice the change in ambient air temperature. 

With many satisfied customers experiencing brilliant on-farm results we know every day can be a cool day for your cows. Cool cows are happy cows that can achieve their full potential and maximize performance. 

For more information, Talk to a Core Cool representative or check out www.corecoolsystems.com