Water: The Unappreciated Nutrient

By Warren Rusche

Water might be the Rodney Dangerfield of nutrients—it just doesn’t get any respect. We could use the latest edition of “Nutrient Requirements of Beef Cattle” as an example. Of the six classes of nutrients discussed in that resource, water is the last topic and the shortest chapter even though water makes up 99% of every molecule in an animal.

It is easy to fall into a trap of assuming that as long as water is present, the animal’s needs are being met. However, the availability of water does not guarantee consumption. Water intake is strongly linked to feed intake so any factors that cause cattle to drink less will lead to reduced feed intake and consequently reduced performance.

Water consumption and heat stress in cattle

Water intake and water quality issues become more pronounced during the summer. Cattle need to drink more during hot weather to relieve heat stress. Some of the dams or streams that non-confined cattle use in the summer may have less than optimal water quality due to sulfate or dissolved solids issues. Warm weather also leads to increased microbial and algae growth; further compromising water quality especially if there is also fecal contamination.

Make certain there is sufficient water space and water delivery capacity during hot weather. During heat stress events the amount of space required per animal triples. If necessary, provide additional water tanks in the pen.

Fecal contamination reduces water consumption

Researchers in Canada observed that yearlings that drank from clean water sources (from a well or stream directly into a trough) gained 20 to 23% more weight compared to yearlings that drank from a pond, either directly or if the pond water was pumped into a trough. Calves on cows showed a similar response with a 10% advantage to drinking from a clean water source.

These researchers also studied the effect of fecal contamination on water preference as well as water and feed consumption. They found that cattle tended to avoid water with as little as 50 ppm fecal contamination. Cattle ate less feed at 2500 ppm manure contamination. That represents as little as a half an ounce of fecal material in a gallon of water.

Effect of water on starting calf success

Monitoring waterers and water quality is critically important for starting calves. Insufficient dry matter intake during receiving can impact immune response, health outcomes, and ultimate cattle performance. Keeping waterers clean is important for any class of confined cattle, but especially true for just weaned calves.

In some cases, the issue is less water quality but whether the calves know how to get a drink. Calves could not drink (and consequently eat very little) if they have never seen a waterer or water tank before. Letting waterers run over for a day or so will mimic the sights and sounds of natural water sources and help entice calves to drink.

Test water for excess dissolved substances

Some regions of South Dakota are plagued with water quality issues. High sulfate levels can be particularly challenging as they are associated with reduced intake, poorer mineral metabolism, and increased risk of animal health issues. A more detailed discussion of sulfate concerns with livestock water can be found in the article, How Do Sulfates in Water Affect Livestock Health?

Sulfates are one concern, but other substances such as Total Dissolved Solids also can affect livestock performance. Testing the water offers the surest method to determine if the water consumed by livestock could pose any issues. Water from natural sources that varies with weather conditions such as drought or precipitation runoff should be sampled more frequently compared to well water which should be more consistent. A listing of laboratories that offer water testing services can be found in the publication, Feed & Water Testing Laboratories.