Are your cows and heifers drinking enough water?
On many farms, that is the $64,000 question. Without a water meter on water lines that supply water tanks, it can be difficult to judge how much water your cows and heifers consume. However, that’s not the only way to judge water intake. Gather clues from the animals themselves.
If your animals suffer from poor growth, poor reproductive performance, have more than the normal number of illnesses and poor milk production, it could be that water is a limiting factor. Sometimes, a lack of water intake can trigger or compound these production-related problems.
Use this guide to help determine if the waterers on your dairy are contributing to poor animal performance.
Cover the basics
Start by covering the basics. Does the tank, bowl or fountain contain fresh water?
Most people know that waterers need to be cleaned on a regular basis — preferably weekly. But what they don’t know is that the presence of algae and other decaying plant material can cause low levels of electrical voltage and current, in addition to causing off-flavors in water. Even a small, barely detectable amount of current can cut water intake.
If cleanliness is not a factor, you may want to test the water supply for mineral content. One or more minerals — in excess amounts — may be giving it an off taste, or perhaps even increasing its electrical conductivity.
The other basic factor to consider is accessibility. Can all animals in the pen get to the waterer easily? You should provide a minimum of two waterers per group of animals. Is there enough room for the animals to drink? For cows, you need a minimum of at least 2 linear feet of tank perimeter space for every 10 to 15 cows. Is the water level in the tank at the right height to encourage consumption? The water level should be within 2 to 4 inches of the top of the tank. Are crossovers or traffic lanes so narrow that a boss cow can block cows from a waterer? (For more information, see “Give her room to drink”).
Check for voltage
Research and field experience has shown that low levels of stray electrical voltage on a water tank, water bowl or in the water itself will reduce water intake.
During the winter months, heating elements used to keep waterers from freezing can be the cause of stray voltage. Even after you turn the heating elements off in the spring, you can still have voltage from the heating element wiring due to improper grounding or voltage on the utility or farm neutral.
Problems also occur when portable water tanks get pushed against an electric fence. You don’t even have to have solid contact. Intermittent contact is enough to send your cows and heifers a little tickle when they drink from the tank, causing a reduction in water intake. Depending on the amount of voltage reaching the tank, it can deliver enough current, and pain, to stop the animals from drinking altogether.
At one farm, for example, the managers sensed a problem when a pen of 36 heifers and a few miniature donkeys drank less than 10 gallons of water in 36 hours. Using a voltmeter and a resistor box, it was determined that 0.08 milli-Amperes (mA) of current were flowing through the heifers whenever they took a drink. It turned out that the heifers had pushed the 350-gallon RubberMaid™ tank into an electric fence. While rubber is a poor conductor of electricity, and most people who place a hand in the water would not have been able to feel anything, it was enough to stop the heifers from drinking water. After the tank was moved away from the fence, and the voltage problem resolved, the heifers drained the tank in less than 30 minutes.
In another example from the same farm, a metal bracket connected to the float valve had somehow come into contact with an electric fence. (Please see the photo above.) The metal bracket was a conductive pathway for current into the water. Testing revealed that currents were up to 1.73 mA alternating current and 1.55 mA direct current. (In addition to voltage from the electric fence, a stray voltage problem also was discovered — hence why there was both ac and dc current detected at the waterer.) That level of current is enough for both cows and humans to definitely feel a jolt. The problem was discovered because 28 heifers had not drank a measurable amount of water in more than 24 hours.
Such incidents are rare. But, they do show that it only takes a small amount of electrical current to alter the drinking behavior of cattle.
Cattle can feel current at lower levels than humans do. You may be able to stick your hand in a water tank and not feel a thing. But your cows — because they have only one-tenth of the resistance to electrical current that people do will feel the tingle of current pulsing through them.
Any voltage of 0.25 volts or more between any two contact points in the animal environment is cause for concern. Voltage detected within the animal environment can be the result of faulty design or maintenance at the farm or utility level. Undersized or overloaded conductors, poor connectors, faulty equipment, or inappropriate levels of grounding on either the farm side or the utility side of the equation can cause stray voltage problems.
So, the next time you’re trying to determine why the cows and heifers are not drinking as much water as you’d like, check the waterers for stray voltage. Even the presence of small amounts — so small that you cannot feel it — can be enough to reduce water intake in cattle.
Gerald Bodman is an agricultural and structural engineer in Bloomsburg, Pa., and a dairy producer.
Water requirements for dairy cattle
Animal – gallons/animal/day
Calves* – 6 to 10 (*1 to 1.5 gal/100 pounds of weight)
Heifers – 10 to 15
Dry Cows – 20 to 30
Lactating cows – 35 to 50 +
Source: Dairy Free-stall Housing and Equipment, Midwest Plan Service, 1997.