By Sam Leadley
What’s “normal” water intake? When water is offered free choice to calves starting the second day of life, we expect three major factors to influence consumption:
• Individual animal variation
• The greater the amount of milk or milk replacer fed, the lower the level of water intake
• The higher the environmental temperature, the higher the level of water intake
On one hand, individual calf variation is a huge factor. You probably have had a calf that started drinking water at day two. Or remember the calf that would not touch water until you drastically cut back the milk or milk replacer? One study found that even though the average amount drunk was 2.4 quarts daily, the individual variation was from none to 19 quarts. So much for “normal.”
On the other hand, probably at least two-thirds or even three-quarters of our calves do fit a pattern. During week one there may be minimal consumption. By week three, many calves offered free choice water are regularly drinking at least one quart daily.
One study feeding acidified milk replacer free-choice found that calves would drink a lot of milk and very little water. At 7 weeks calves were up to 13.6 quarts of milk replacer daily and less than 1 quart of water.
For those of us manually feeding calves, the difference between 4 and 6 quarts a day probably won’t have much effect on water consumption. With calves in cold housing, we’ve all observed how low water intakes fall during subfreezing weather. Jim Quigley, director of calf operations for American Protein Corp., measured water intake with air temperatures between 32 and 95 degrees (See www.calfnotes.com Calfnote #68). An 18-degree change in temperature from 32 to 50 degrees increased water intake by about 0.4 quarts daily. But a much smaller, 9-degree change from 86 to 95 degrees increased intake 0.5 quarts daily. Increases at higher temperatures mean drastically greater increases in water needs than similar temperature changes when it is cool.
Clean water in clean pails
One common challenge is regularly providing clean liquid water in clean pails. A research project measured the effect of the availability of clean water on growth rate (Table 1). Researchers assumed that calves would drink more water if it was fresh and in a clean container. For preweaned and transition calves they varied the interval at which the water pails were rinsed and cleaned.
In both instances the researchers measured 0.2 pounds per day difference between clean and “not so clean” water. This supports their assumption that fresh, clean water in clean pails and tubs promotes higher growth rates. With higher water consumption associated with greater dry matter intake (DMI), the calves gained 0.2 pounds average daily gain, or 14%, more than calves with lower intakes. Similar findings came out of a comparison of the placement of water and grain pails. When the pails were separated physically or by a barrier there was a 33% increase in water consumed and an 18% improvement in body weight gain per day.
The biggest benefit to providing free choice water to preweaned calves is increased DMI. This translates into a higher rate of gain and indirectly to improved health. In Table 2, we see that calves with free choice water consumed 45% more starter grain than the calves without water.
These “free-choice water” calves also gained 60% more weight in the first four weeks. Estimates are that for efficient feed conversion, calves need to consume at least four pounds of water for each pound of DMI.
Practical summer tips
For summer management many farms keep an extra supply of water pails. A number equal to about 20% of calves on milk makes sense. Then each day of the week, one-fifth of the pails can be replaced with clean ones and the dirty ones can be scrubbed for the next day. In five days all the pails have been cleaned. Algae and mold are controlled.
For calves in the weaning process or already weaned, water consumption in hot summer weather is often very high. Many will drink more than ten quarts daily. This may be a point where larger pails may be added to the hutches or pens. Some farms have a collection of 5-gallon pails that are clipped to the hutches or pens around weaning time. These larger pails permit once-a-day watering.