by Dr. Meg Smart, Veterinary Internal Medicine, University of Saskatchewan, Saskatoon
The water requirements of cattle can be influenced or altered by age, diet, production, and enviromnent. To optimize production, the producer must ensure adequate water intake. If water intake is restricted by limited access or poor quality water (e.g. total dissolved solids > 5,000 mg/L) then the total daily feed intake is reduced while the cattle adapt. There is a high correlation between water intake and feed intake, and this can have a significant economic impact if a producer's aim is to optimize feed intake, e.g., dairy cattle in early lactation or in newly arrived feed lot cattle. Water can contribute significantly to total dietary mineral intake (calcium) or to dietary interactions (sulphate decreases copper availability). These will be discussed in future newsletters.Water requirements are met primarily by voluntary consumption. Metabolic water (water produced by body metabolism) and water consumed with feed also contribute to daily water intake.
Ambient temperature:
Above 27ºC the daily water intake doubles.
Pregnancy:
Last four months voluntary water intake increases 30-50% above maintenance.
Milk Production:
For every kilogram of milk produced, 0.87 kg of water is required. During lactation voluntary water
intake should equal milk yield.
Trough Space:
One waterer for every 6-10 cows or total water trough space should allow I 0% of herd to drink at
one time. Most cows can drink at a rate of 16-27 L/min.
Water Temperature:
Variable effect on intake. Heating water in winter may increase water consumption.
[gallons water/kg dry diet] |
||
|---|---|---|
| Calves 1-5 weeks | 4.4 to 7.5 [1.2 to 1.7] | |
| Adult (maintenance) | 3.5 to 5.5 [.8 to 1.3] | |
| Late Pregnant | 30 to 50% above maintenance | |
| Lactating | 1 L/kg milk above maintenance | |
| Above 27º (maintenance) | 6.6 [1.5] | |
| *these are only approximate values to be used as a guide | ||
Type of Ration:
High moisture feeds tend to decrease voluntary water intake but increase overall water intake. High
protein diets and salt increase water intake.
Age:
Calves require a higher intake of water than adults. To optimize feed intake in preparation to weaning, a producer must allow calf to drink fresh water.
