Ask any dairy producer who uses sprinklers and fans what the biggest problem he encounters with his current system, and the answer almost always is "drift." He's refering to droplets that drift into the stall beds and land on the feed in front of the cows.
With that problem in mind, researchers at Kansas State University set out to develop a system that would wet the cows, but keep the stall beds and feed dry. Extension dairy specialists John Smith and Mike Brouk and agricultural engineer Joe Harner have designed a soaker system that meets this goal.
Here's how to install the soaker system in your free-stall barn.
Step 1. Locate water supply lines and determine if you have enough volume to run the system. How much water you will need depends on the nozzle size you select, the pipe diameter and the length of feed line that the system will cover. Use the chart on page 37 to help determine if your water supply line has enough pressure to run the entire system at once, or if you will need to set up zones so that only certain pens run at one time.
In the past, producers have installed sprinkler or mister systems and lived with the consequences of an undersized water supply system. The result is often sprinklers or misters running at one end of the line, but not at the other. Or, different nozzles put out different amounts of water. By evaluating your water supply first, you can avoid these problems.
Step 2. Determine the pipe size that you will need. The K-State dairy team recommends placing nozzles about every 6 to 8 feet, and they prefer to use nozzles that can deliver 0.5 to 1 gallon per minute so that you can quickly soak the cows. Using those numbers, refer to the chart below to determine the size of pipe you will need.
For example, if you use nozzles that deliver 1 gallon per minute, and the feed line is 100 feet long, you would have 12 nozzles and would need a 1-inch diameter pipe.
Both Schedule 80 PVC pipe and steel pipe will work. The only difference is PVC pipe may need a support system, depending on post spacing. The steel pipe can be attached directly to posts in the barn without any additional support.
Step 3. Determine if you need a pressure reducer. For the system to work effectively, you will need a constant water supply in the pipe of 20 pounds per square inch when the system is turned on. If your water supply sometimes streams out rapidly when you turn on a faucet, you may need a pressure reducer. Work with a plumber or your building contractor to determine if you need a pressure reducer.
Step 4. Decide what type of nozzles you will use. You can use any brand of flood nozzles with a 120- degree spray pattern that contains a check valve.
The spray pattern size and the check valve are keys to making the system work as intended. The 120-degree spray pattern is preferred, as it will not get the feed wet like a 180- degree spray pattern can, but still provides the overlap you need to get uniform moisture on all of the cows. The check valve prevents water from dripping out of the nozzles when the system shuts off. That means the water left in the pipe at the time the system was shut off remains in the line. And, the next time the system turns on, all of the nozzles will come on at once because the water line stays filled with water.
You can use brass or plastic nozzles. However, if you use plastic nozzles, you will need to mount metal tabs on the steel supply pipe or on the support system used to hold up the PVC pipe in order to protect the nozzles. (See the photos above.)
Step 5. Pre-drill and tap holes in the pipe. Before you hang the pipe above the headlocks, or above the rail in a post-and-rail feeding system, you'll want to drill holes every 6 to 8 feet and use a tap to cut in threads so that you can screw in the nozzles later.
Step 6. Mount the pipe as close to the headlocks as you can without interfering with the release mechanism for the headlocks. In most cases, that is about 5.5 to 6 feet above the floor on which the cows stand.
The pipe should be mounted on the inside of the post (the cow side). Use U-bolts or pipe clamps to secure steel pipe to the post. If you use PVC pipe, you will need to use some sort of support system, such as angle iron to hold up the PVC pipe.
When you position the pipe, rotate the pre-drilled holes toward the cows. Use rubber pipe and pipe clamps to splice steel pipe together. (See picture above.) The rubber pipe splice allows you to easily replace a section of pipe in case someone hits the pipe with a skid-loader or otherwise damages the pipe.
Step 7. Once you have the pipe hung, then you can screw in the nozzles. You will need to use silicon gel or teflon tape to seal the connection. With the teflon tape, you simply place the tape around the threads before screwing it into the pipe. And, with the silicone gel, just apply a liberal amount on the threads before installing. Position the nozzles so that the spray hits the cows just behind the shoulders.
Step 8. Install a manual shut-off valve at each pen. That way, if the soaker system comes on when you and the veterinarian are working cows, you can simply shut it off without having to leave the pen.
Step. 9 Install a temperature controller that will shut the system on and off automatically based on the temperature. In systems where a temperature controller is not installed, producers tend to run the sprinklers or misters continuously when the weather gets really warm. They set it for the worst case scenario for the day and that fills up their lagoon rather quickly.
Instead, the K-State team recommends using a controller and setting it as follows (assuming the nozzles deliver at least 0.75 gallons per minute):
At 70 F to 80 F, run every 15 minutes for one to two minutes.
At 80 F to 90 F, run every 10 minutes for one to two minutes.
Above 90 F, run every five minutes for one to two minutes.