With areas of Oklahoma having extended drought conditions, many of its groundwater sources are drying up. This can force cattle to consume water from sources they would normally avoid. Cattle can only survive a few days without water, and addressing the water needs of cattle is a complex process depending on water quality, weather patterns, time of day, feed moisture content and animal factors such as body weight and stage of production.
Water intake and feed intake are closely related, so water shortages will impact productivity because of the water requirements and decreased consumption of other nutrients. For example, in one study, cattle in the southeastern U.S. were provided with unrestricted access to water, had a 48-hour water restriction before shipment to a Texas Panhandle feedlot, or had alternating 24-hour periods of water restrictions over seven days prior to shipment.
Dehydration increased short-term measures of stress after transport, and performance was reduced during the initial two weeks at the feedlot in water-restricted calves. This research shows that relatively short periods of water restriction, common in our livestock marketing channels, can have impacts beyond the time of the restriction.
Common water quality issues for cattle include fecal and bacterial contamination, nitrates, hardness, salinity and total dissolved solids (which include salt, calcium, magnesium, phosphates, silica and sulfates). Cattle consuming water with salt or total dissolved solids greater than 10,000 parts per million (ppm) have reduced growth and increased water consumption so that urinary output can increase in order to expel the increased total salt intake.
In livestock water, it is recommended that nitrites be limited to less than 33 ppm, nitrates less than 45 ppm, sulfates less than 300 ppm and total dissolved solids less than 1,000 ppm, but livestock can often withstand higher levels of contamination, depending on other factors.
To achieve guidelines, all sources of water should be sampled and analyzed for nitrates, sulfates and total dissolved solids. Blending water from multiple sources may reduce potential quality issues. Avoid stacking sulfur and nitrate risk factors by sampling and analyzing forages and byproduct feeds used on the ranch.
Estimates of water intake by feedlot cattle include daily feed intake, daily maximum and minimum temperatures, wind speed, solar radiation, the season and the temperature-humidity index. Peak water demands by heavy cattle near finishing during the summer can exceed 20 gallons per day, the majority of which is consumed between 5 a.m. and 9 p.m.
A 550-pound grazing calf consumes up to 12 gallons per day, but this occurs in a much more limited time frame due to grazing patterns and distance traveled to water. It is important to consider average water consumption over a season when developing water resources and planning watering systems. Also consider drinking behavior, timing of water consumption and maximum daily water needs. — Paul Beck, Oklahoma State University Extension beef cattle nutrition specialist
