Mike Gamroth, Oregon State University
Water is often the single greatest factor restricting the development of more efficient grazing systems. Movement of grazing animals to and from water can create unproductive time (animals traveling and not grazing), increase soil erosion along animal trails and lanes, and contribute to poor manure distribution.
Water must be available, and it needs to be as clean and fresh as possible. Producers have observed that animal production is increased when the herd is switched from pond water to well water or rural water delivery systems.
Recent grazing management research indicates that animals should be no farther than 800 feet from water for most efficient grazing. There are basically two approaches to supplying water. One is to let the animals move to the water. The second, and more desirable, approach is to move the water to the animals. There are many new technologies for delivering water to grazing animals. Examples include burst-proof pipe, quick couplers in water lines that allow moving small watering tanks around the pasture areas, and new pumping equipment.
Various pumping systems have been tested and evaluated by graziers throughout the United States. Solar pumps, water rams, water slings, and nose pumps are all means of moving water to livestock, but some of these are only appropriate for small grazing group of 25 to 30 cows. Producers should take advantage of the more experienced graziers in their area to observe the methods they are using to deliver water.
Portable water in pasture. Photo credit: Debra Heleba, University of Vermont Extension.
When calculating the actual water requirement of grazing animals, remember that it varies throughout the year. Lactating animals have higher water requirements than other classes of animals. Environmental stress—particularly high temperature and humidity—also can drastically increase the water requirements of grazing animals. A general rule for planning water resource needs is that animals consume roughly three times the amount of water per day as they do dry matter. Using this guideline for a standard animal unit (one 1,000-lb cow with or without calf consuming 26 lb of dry matter per day), it is estimated that the animal is drinking 78 lb of water, or roughly 10 gallons daily. However, animals under heat stress and/or during lactation may require two or three times this average daily water need.
When an improved grazing system is planned and implemented, increased stocking rates should occur over time. The watering system must be designed to deliver water at a rate that exceeds the requirements of the grazing herd at peak water consumption. The water system must be designed to provide a minimum refill rate of 0.5 gal/minute/animal.
Information on water pressure, pipe sizing, and flow rates needed to match water delivery systems with animal requirements is included in a publication, Private Water Systems Handbook, available from the MidWest Plan Service, Iowa State University. This organization also has publications with plans for corrals and animal handling equipment for dairies and grazing systems.
- Midwest Plan Service. 2009. Private water systems handbook. MWPS-14. Fourth Edition. Iowa State University, Ames, Iowa. Ordering information available at: http://extension.missouri.edu/publications/DisplayPub.aspx?P=MWPS14 (verified 22 Mar 2010).