Don’t Overlook the Importance of Water in the Diet

Water is the cheapest, most vital nutrient in dairy cattle diets. Yet cleanliness and availability are often overlooked. Studies have shown that a lactating cow will consume 30 to 50 gallons of water a day, and this can double if an animal is experiencing heat stress.

According to Carly Becker, a dairy extension educator and Pennsylvania State University, the size of the cow, production level, amount of dry matter consumed, temperature and relative humidity of the environment, temperature of the drinking water, quality and availability of the water, and amount of moisture in her feed will influence how much water a cow drinks throughout the day. Therefore, ensuring all cows have an ample, clean water supply is a vital management practice.

Space Recommendations

Throughout the day, cows will spend approximately 10 to 60 minutes drinking water. However, if the waterer space is not large enough or the water flow rate is too slow, cows may have to wait to meet their water needs or they may not get to drink at all during their visit to the waterer, Becker notes. To ensure each cow is allowed the appropriate drinking time it is essential to provide adequate drinking space. Drinking space recommendations include:

• 2 to 4 inches of perimeter space per cow
• Optimal water tank height ranges from 24 to 32 inches
• Water depth should be a minimum of 3 inches
• At least 2 watering locations per pen to prevent dominant cows from guarding the waterer
• Provide enough space at the waterer so that 20% of the cows in a group can drink at once
• Water tank located within 50 feet of the feed bunk or at every crossover in a freestall barn
• Water should be immediately accessible after returning from milking
• Heifers should have access to one appropriately sized water space per 20 animals
• The same recommendations go for cows and heifers on pasture

“An important fact to remember is that cows will drink 30% to 50% of their total daily water intake within 1 hour or so after milking,” Becker adds.  “This time is also a peak period for cleaning milking equipment; therefore, water flow going to the waterers may decrease. Water flow rates should be observed at these heavy use times and altered accordingly.”

Water Quality

Water quality is another important factor to monitor a couple times a year, Becker notes. A water sample can be collected from your farm and sent to a laboratory to be evaluated for chemical and physical aspects such as minerals, nitrate-nitrogen, total dissolved solids and bacteria content.

“Waterers should be emptied and cleaned with a weak chlorine solution and refilled with fresh water at least weekly to maintain water freshness and quality. This includes calf and heifer water buckets, bowls, and tanks,” Becker says.