Is water the limiting resource on your dairy?
|Water intake for lactating cows can range from 18 gallons per day for a cow producing 40 pounds of milk, consuming 42 pounds of dry matter, during a week of temperatures averaging 40˚F to 36 gallons per day for a cow producing 100 pounds of milk, consuming 60 pounds of dry matter, during a week of temperatures averaging 80˚F. Water intake may increase 1.5 to 2 times greater during times of heat-stress. The needs of dry cows and calves also change with the weather. Photo by Dieter Krieg|
By SHERRY BUNTING
Special for Farmshine
EAST EARL, Pa. -- “Are feed intake and milk yield less than expected because water intake is low? Or, is water intake below normal because of low feed intake and milk production? These are always difficult questions to answer,” says Michigan State University animal scientist Dr. David Beede in his “Evaluation of Water Quality and Nutrition for Dairy Cattle.”
“... There is a direct positive relationship between water intake and feed intake. But what factors affect this relationship?” Beede notes. “If problems are suspected, the quality of drinking water, the placement and management of watering stations in the cows’ and calves’ environment, and other factors known to affect free drinking water intake should be assessed carefully.”
Beede explains quality factors not only affect performance and health once ingested, quality factors also affect intake. To determine if off-quality water is affecting how much cows are drinking, check:
• odor and taste,
• physical and chemical properties,
• presence of toxic compounds,
• concentrations of macro- and micromineral elements, and
• microbial contamination.
Water placement and management
Providing ample space for drinking and enough waterers, in strategic locations, ensures cows will drink all the water they need. Studies show a positive relationship between rolling herd average and management of three key water intake priorities:
1. Amount of space or access to water
2. Distance from feedbunk to waterer
3. Frequency of cleaning waterers and water bowls.
Here are some things to strive for:
• The ideal trough is described, based on farm studies, as having a length of at least 2 to 4 inches per cow, with a height of 24 to 32 inches. Water depth should be a minimum of 3 inches to allow cows to submerge the muzzle 1 to 2 inches.
• At least one waterer should be provided for every 15-20 cows (or a minimum of two foot of tank space per 20 cows).
• A prime location for waterers is the parlor exit and return lanes. A cow will consume 30-50% of her daily water intake within the first hour after milking, making this a very critical time to ensure her access to plenty of clean, fresh water.
• In freestall / parlor setups, water should be provided within 50 feet of the feed bunk. Crossovers are a good location, where cows tend to drink the most.
• In grazing operations, water should be located at the parlor exit and in each paddock so animals are always within 600 feet of a clean, fresh water source.
• In tie-stall barns, shared water bowls can limit intake. Both cows should have easy access. Observe cows for intimidation behaviors between neighbors, which can limit one of the two from drinking the water she needs.
• Test the water flow by running it over into a bucket for one minute. Then measure. The absolute bare minimum is 1 gal/minute, but this really should be 3 gal/minute, particularly during summer heat stress when cows have a higher water intake requirement. A cow is capable of consuming 3 to 5 gal/minute.
How much water do dairy animals need?
Cows lose water through saliva, urine, feces, and milk; through sweating; and by evaporation from body surfaces and the respiratory tract. The amount of water lost from the body of cattle is mainly affected by their activity, air temp, humidity, respiratory rate, water intake, feed intake, and milk production.
The amount of water a cow will drink depends on her size, milk yield, quantity of dry matter consumed, air temperature and relative humidity, water temperature, quality and availability of the water, and amount of moisture in her feed.
Water is an especially important nutrient during periods of heat stress, acting to transfer heat from the body.
During periods of cold weather, water acts as insulation, helping the animal to conserve body heat.
Water intake for lactating cows can range from 18 gallons per day for a cow producing 40 pounds of milk, consuming 42 pounds of dry matter, during a week of temperatures averaging 40 degrees F.—to 36 gallons per day for a cow producing 100 pounds of milk, consuming 60 pounds of dry matter, during a week of temperatures averaging 80 degrees F. Water intake may increase 1.5 to 2 times greater during times of heat-stress.
Water intake for dry cows is affected mainly by dry matter intake, concentration of dry matter in the diet, and protein content of the diet. For example, a 1,500-pound non-lactating cow consuming 28 pounds of dry matter, containing 12% moisture and 12% crude protein, would consume 11.6 gallons of water per day at air temperatures averaging between 50°F and 80°F. Water intake may increase 1.5 to 2 times greater during periods of heat stress.
Calves, during the liquid feeding stage, receive most of their water as milk or milk-replacer. However, studies show calves that are offered free choice water in addition to a liquid diet, gain faster and consume dry feed earlier than calves receiving their water needs only from the liquid diet. Weaned dairy heifers consume approximately 1 to 1.5 gallons of water per 100 pounds of body weight.