Water provision

Adequate provision of water is essential in any dairy housing system. Any restriction in water supply will have an immediate effect on milk yield. Good quality water supplied through adequate, reliable and readily accessible drinking facilities must be provided.  Allowing cows to drink from streams and other water courses is discouraged due to disease risks from contaminated water and can lead to water pollution, erosion of banks and habitat damage.

The water requirement of a cow will depend on a variety of factors, including milk yield, dry matter content of the feed, stage of lactation and ambient temperature. High yielding cows can require up to 5 litres of water for every litre of milk they produce.

Daily drinking water requirements

Daily milk yield

20 litres

30 litres

Temperature

<160C

16 - 200C

>200C

<160C

16 - 200C

>200C

Ration DM%

 

 

 

 

 

 

30

50

57

65

71

82

94

40

54

62

71

76

87

100

50

57

66

76

79

91

105

60

62

71

82

84

96

110

70

64

74

85

87

100

115

Cows prefer to drink from a trough than from natural water sources, such as streams.

Peak drinking water demands coincide with the completion of milking and around sunset.  Up to 50% of the cows' daily requirement can be consumed during these times. As cows can drink at the rate of 15-20 litres/min, it is important to recognise these peak periods and provide adequate trough capacity, bearing in mind the flow rate of the water supply.

A flow rate to the trough of 10 litres/minute is suggested as a minimum.

Because dairy cows are sociable in their behaviour, it is important that there is adequate trough space to allow 10% of the herd to drink at any time. A minimum of 10cm/cow available drinking space is recommended. 

Water troughs should be placed in areas that allow easy access and not in a dead end. They should be checked daily and cleaned regularly. Cows can become more aggressive around a water trough, therefore, it is necessary to have more than one trough available to the cow group to allow for social rank differences within the herd.

Trough size is important; studies have shown that cows prefer to drink out of larger troughs when given the choice. As a rule of thumb, the surface area of the trough should be at least 1.0 m2 for every 60 cows in the group.

The water trough should be located at the correct height for the cow. The edge of the trough should be 850mm from the floor. The water level should be 50-100mm below the edge of the trough to minimise splashing. 

The provision of fresh, clean water is important to maximise intakes. A high turnover of water through a trough will improve water quality. Tipping troughs or installation of large bore drain holes (50-75mm) all ease the task of keeping water clean.

Water flow rates must be capable of supplying the peaks of demand. Where water pressure is low, booster pumps or extra covered storage tanks (that can fill during low water demand times) should be considered. Where water pressure is adequate, poor flow rates may be improved by using a larger supply pipe. Doubling the diameter of this pipe can increase the flow to the trough by up to six times.

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