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High-quality water is necessary for calf health

Ellan Dufour for Progressive Dairyman Published on 11 March 2019

Water – which makes up 86 percent of a newborn calf’s bodyweight – is the most important nutrient for dairy calves, but it is often overlooked.

Water is required for all of life’s processes, including cell life, chemical and metabolic reactions, nutrient transport and digestion, waste removal, regulation of body temperature and the maintenance of a proper fluid-ion balance in the body.



Young calves and importance of high-quality water

Offering calves free-choice water is critical for stimulating rumen development, improving grain fermentation and promoting starter intake. The quality of water offered can play a major role in both nutrient utilization and the overall health of the calf.

Calves are around 70 to 75 percent water by bodyweight and need to consume fresh water in order to maintain normal cellular functions. Dehydration can lead to weakness, severe weight loss and even death. Signs of dehydration include sunken eyes, dry nose and mouth, tacky gums, depressed demeanor, irregular pulse, and cold legs and ears.

Unlike milk and milk replacer, water consumed by young calves is transported to the rumen rather than the abomasum. Water in the rumen is essential for ruminal bacteria growth and provides a medium for bacteria to ferment starter grain and hay. Microbial growth and development, and the absorptive ability of rumen tissue, are slowed in the absence of water.

Calves offered free-choice water, in addition to their milk or milk replacer diets, are shown to gain weight faster and consume dry feed more quickly than calves only receiving water through their milk or milk replacer. Researchers in the 1980s conducted a water study and found calves receiving free-choice water saw a 60 percent increase in weight gain and a 45 percent increase in starter intake in the first four weeks of life, compared to their counterparts receiving no water.

How much water is required and when?

On average, pre-weaned calves should consume 1 quart of water per pound of dry matter intake (DMI); post-weaning, they should consume 2 quarts of water per pound of DMI. This ratio should extend through the heifer growing period.


Calves have an increased need for water during times of stress, including heat stress, cold stress, low humidity and disease-related loss. In hot weather, expect water consumption to increase by 33 percent or more when temperatures exceed 75ºF, and anticipate that consumption may double in temperatures above 90ºF.

Young calves can lose 10 to 12 percent of their bodyweight due to water loss during incidents of scours or diarrhea, meaning keeping sick calves well hydrated is of the utmost importance.

Factors affecting water quality

Offering poor-quality water to a young calf may impact the calf’s water consumption, starter intake, general health and rumen development, as well as the value of milk replacer and electrolytes. There are many criteria involved in assessing water quality, including odor and taste, pH, salinity, excess minerals, toxic compounds and the presence of bacteria (Table 1).

Guidelines for youngstock water quality

Water hardness is a measure of suspended inorganic constituents in water, including sulfates, nitrates and sodium, among others. Calves are very sensitive to sodium and struggle to tolerate excess sodium levels. Soft water, or water that has passed through a water softener, can have very high concentrations of sodium and therefore should not be used to mix milk replacer or be offered as drinking water unless tested.

High sodium levels can lead to neurological diseases and central nervous system derangement in young calves. Although research is limited in young calves, studies have shown desalinated water offered to lactating dairy cows increases both daily water consumption and daily milk yield.


High levels of sulfates can have a laxative effect, tying up important trace minerals and reducing their ability to be absorbed and utilized by the calf. High-nitrate water can also be of concern for young calves, as excess nitrates will convert to nitrite in the rumen and can lead to symptoms such as asphyxiation, labored breathing, elevated heart rate, mouth frothing, convulsions, blue discoloration of mouth and eyes, and chocolate-brown blood, if absorbed through the rumen wall.

In situations when total solids are high in milk or milk replacer (i.e., over 15 percent), offering high-quality water can sustain the osmotic equilibrium in a calf. High-total solids can force water out of cells in an effort to find osmotic balance within the gut and can result in diarrhea and/or severe dehydration. Water provision is especially important for calves fed an accelerated milk program in order to ensure full digestion of milk solids and to maintain proper hydration for the animal.

Coliform bacteria like E. coli and salmonella may be present in poor-quality water or in water contaminated by feces and can quickly and exponentially increase to dangerous levels for calves if consumed. In both cases, calves may suffer from severe dehydration and diarrhea. Salmonella may also result in pneumonia and septicemia in infected animals.

Calves are more sensitive to elevated mineral levels than adult cattle, making excessive mineral concentrations in drinking water particularly concerning. The upper concentrations and maximum tolerable concentrations of minerals for youngstock are shown in Table 1. The minerals that, when found in high concentrations, are of most concern include cobalt, copper, iron, hydrogen sulfide, manganese and sulfur.

Table 2 provides a general guide for water treatment methods. Calves may not show any obvious health symptoms when water quality is poor, but poor water quality may affect their future performance and productivity later in life.

General guide for treatment methods to remove unwanted constituents from drinking water

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To ensure calves stay healthy, provide them with clean, fresh and readily available water. Make sure water buckets are clean and free of contamination from starter feed, hay, bedding and feces. It is important to regularly test your water source to ensure your calves are receiving high-quality water – and to know the least expensive and most efficient method to correct any water quality abnormalities. At a minimum, water quality should be tested annually.  end mark

Ellan Dufour
  • Ellan Dufour

  • Dairy Research Nutritionist
  • Hubbard Feeds
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