Mist and fogging nozzles are often used to cool dairy cows by cooling the air around the cows. Unfortunately, the mist can be easily blown away under windy conditions or when used with fans. If a mist or fog builds up on the cow’s hair, it can trap a layer of air between the skin and the water holding in body heat. In addition, mist and fogging nozzles are often operated at high pressures and require regular maintenance. In comparison, high-capacity Edstrom soaker nozzles produce a coarse droplet spray which penetrates the hair and wets the cow to the hide. Edstrom soaker nozzles operate at reduced water pressure of 10 to 20 psi. The water is then allowed to evaporate, pulling heat from the animal, just like sweating. Air movement across the wet hide, provided by fans, makes this system most efficient. Proper control is critical to ensure that the cow gets soaked to the hide along the topline while not getting wet to the point of having water running off the sides.
Normal recommendations are to shower the animals for a short period of time, 0.5 - 3 minutes, to soak the hide. After the shower shuts off, the water is evaporated from the cattle by fans blowing across their backs for 5.0 to 15.0 minutes, before repeating the shower cycle.
Common locations for installing a shower cooling system are in the Holding Pen area, where cows are crowded together tightly, and in the feed line area. There are several steps to follow when designing a system layout.
Location for the Soaker Nozzles
Soaker nozzles should be mounted below the fans so water is directed down onto the cows. The soaker nozzles should not be installed where they will spray into the feed line or a stall area. They need to be located high enough to be protected from animals or equipment, but below the bottom of ventilation fans. In the holding pen area, full-circle (360°) nozzles are recommended, and should be located to obtain 100% coverage of the area to be sprayed. At the feed line, 1/2-circle (135° to180°) nozzles can be mounted along the top of the lock-ups or neck rail and directed to spray out over the backs of the cows. The best control of the water along a feed bunk can be achieved by mounting the nozzles at a height just above the cows’ backs. Space the nozzles every 6 to 8 feet along the feed line. Note: The distribution line may need to be protected by angle iron or some other means if it is mounted in this lower position.