The Enid News and Eagle, Enid, OK

May 25, 2013

Water is essential

By Rick Nelson, Extended Forecast
Enid News and Eagle

ENID, Okla. — Green grass is a welcome sight, especially for everyone coming out of a winter that wouldn’t end.

And as cattle head to summer pasture, focus is on the high-quality nutrition available in that new growth. But there is one essential nutrient — the most essential nutrient — that merits attention.

Water must be available in adequate quantity and quality to support functions ranging from digestion and milk production to blood volume, joint lubrication and waste transport.

Despite the importance of water intake, there is limited research available on measureable impacts of restricted intake or poor water quality. We do know an animals’ requirement for water is driven by a combination of factors: size, feed intake, rate and composition of gain, milk production, activity, ration composition, and of course climate. As the temperature rises from 40 to 90 degrees, cattle will double the amount of water they drink.

Diet impacts water needs several ways. First, as animals eat more, water consumption must increase as well.

Knowing how and when animals drink can have management implications. With adequate access to water, cattle will drink two to five times per day. However, in extensive grazing situations, less frequent drinks will lead to less total intake — and presumably, less feed intake as well. If cows have to travel one-half mile or more to their water source, they will tend to make those trips as a group. If that trip is less than 900 feet, they are much more likely to come individually or in pairs. In situations where the whole herd will come together, there needs to be enough tank capacity to handle 25 percent of the groups’ daily needs at once. It is also important to have enough access for 10 percent of the animals to drink at once.

When water availability is restricted, cattle will immediately respond by decreasing feed intake. This has an obvious impact on growth and reproductive performance. Metabolically, cattle have a very low tolerance for dehydration, and a 10 percent loss in body water is severe. And because one of the roles of water is toxin removal, limited water intake can lead to a dangerous build-up of these compounds in the animal.

Water may contain several types of contaminants that can potentially have a negative impact on animal nutrition, performance and health. These may be naturally occurring (i.e., high mineral levels due to local soil content), due to run-off of chemicals or excess nutrients, or involve dangerous levels of microorganisms. The upper “safe” limit for compounds that are of concern are shown in the table at the bottom.

Studies have been done at South Dakota State University with high-sulfate water. When rural/tap water was substituted for well or dam water, intake of feed and water was increased, along with gains, feed efficiency and health status in steers, and body condition in cows. Colorado feedlot research demonstrated a reduction in ADG, conversion and carcass characteristics with water sulfate levels of 583 ppm. In studies where sulfates were in the 3,500-4,000 ppm range, water intake dropped 35 to 57 percent.

Levels of nitrates, nitrites and sulfates assumed safe for most classes of livestock:

• Nitrate — less than 221 ppm.

• Nitrite — less than 40 ppm.

• Sulfate — less than 300 ppm.

• Total dissolved solids (TDS) — less than 3,000 ppm.

A livestock water test is inexpensive and a sample can be submitted by any extension office.

Nelson is Oklahoma Cooperative Extension Service ag educator for Garfield County.