Water for dairy cows: why quality, access and management matter

Introduction

Water is a finite resource, essential for the life of humans, animals and plants. After oxygen, it is the most important essential nutrient for living beings and the largest body constituent of mammals [8].

Beyond feed, water is a critical component of dairy cow productivity, although it continues to receive less attention than other nutritional and management factors. Traditionally viewed mainly from a nutritional perspective, water is one of the most important nutrients for dairy cows and plays a strategic role in herd management by directly influencing feed intake, thermoregulation, animal welfare and milk production [1, 2]. As dairy systems become increasingly intensive and climate-related challenges become more frequent, an integrated approach to water management is required to support both productivity and sustainability [1].

For dairy cows, water is the most important quantitative feed requirement. It is used for several vital purposes, including digestion – helping break food down into nutrients across the four-compartment ruminant stomach – transport of nutrients through the bloodstream, body temperature regulation through sweating and respiration, waste excretion through salivation, urine, feces and sweat, and as an essential component of milk, which is composed of approximately 87% water [1,2,8].

This article explores these dimensions from an integrated and updated perspective. Emphasis is placed on four interconnected dimensions of water management in modern dairy systems: requirements, accessibility, quality and management [1, 2].

• Water Requirements: Rethinking the needs of high-producing dairy cows in a changing climate
• Water Access: How availability shapes drinking behaviour and performance
• Water Quality: When safety is not enough for optimal dairy performance
• Water Management: A tool to improve dairy efficiency

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How much water do dairy cows need in modern production systems?

Water requirements in high-producing dairy cows should be viewed as a dynamic physiological demand influenced by milk yield, diet composition, environmental conditions and the increasing impact of heat stress [1, 3]. Recent benchmarking studies demonstrated greater water use in confined and high-yielding systems, reinforcing the need for realistic evaluation of farm water availability and production efficiency [7]. As environmental temperatures increase, water becomes progressively more important for thermoregulation, metabolic stability and maintenance of productive performance [3]. Consequently, future dairy systems will require more adaptive approaches to water requirement assessment, integrating physiological demand, climatic conditions and production intensity into water-use planning strategies [2, 7].

The daily amount of water required by dairy cattle is influenced by several factors, such as ambient temperature, live weight, age, stage of life (growth, fattening, and lactation) and metabolic activity rate, which will largely correspond to the level of production of the dairy cow in each phase of the production cycle. On average, in a pasture system, lactating cows drink around 64 litres of water per day; in the semi-confined system, around 48 litres per lactating cow per day; and in the confined system, they drink approximately 89 litres. When water consumption is related to milk production, the values vary from 3.3 litres of water per litre of milk per day in the grazing regime to 3.8 litres of water per litre of milk per day in the confined regime [10].

As for the ambient temperature, it is known that for each increase of 1°C, there is an increase of approximately 1.2 litres of ingested water. The ambient temperature must always be evaluated together with the humidity, because in a more humid climate, dairy cows have greater difficulty in dissipating heat and can enter thermal stress, even if the environmental temperature is low. The reference is that cows are more comfortable with temperatures between 15 and 21°C and with humidity not exceeding 70% [10].

In tropical climates or in the hottest months of a temperate zone, consumption increases as the cows suffer heat stress, with a consequent increase in urine excretion and a change in the composition of the manure. The amount of water ingested follows the consumption of food, and the peak consumption coincides with the peak consumption of dry matter. Another consumption peak is observed after milking, which can represent 40% to 50% of the total daily consumption [8].

Practical considerations

• Monitor water intake during heat stress periods.
• Reassess water availability according to milk yield.
• Avoid relying exclusively on average litres/cow/day estimates.

How does water access affect dairy cow drinking behaviour and performance?

Water access is a major determinant of drinking behaviour, welfare and productive performance in dairy cows. Limited access to water may reduce drinking opportunities and compromise cow comfort. Water intake patterns are influenced by availability, drinkers design, cleanliness, flow rate and location within the housing system [2, 3]. Inadequate drinker availability may increase competition, alter drinking behaviour and disturb behavioural stability, particularly in subordinate cows and during periods of heat stress [4, 5]. These findings reinforce that water access should be considered a central component of welfare and production resilience in modern dairy systems [2, 4, 5].

Drinkers for dairy cows

The number of times the cow goes to the drinker is not a determining factor for the amount of water ingested, as this is directly related to the intake in each drink and not to the number of drinks per day.

It is important to provide dairy cows with fresh, clean water ad libitum. The water must be free of impurities and at room temperature. The following points regarding drinkers are highlighted:

• Place drinkers close to feeding and milking areas.
• Keep water fountains clean and in good working order.
• The water flow in the drinkers must allow it to be renewed at least twice a day.
• Place the drinkers in shaded and wind-protected places.
• Drinkers must have appropriate dimensions so that a greater number of adult cows can drink water at the same time.
• Make sure the water is fresh and tepid.
• Monitor the water consumption of dairy cows to ensure they are drinking enough.

Key indicators associated with insufficient water intake in dairy cows are presented in Table 1.

Table 1 – Indicators of insufficient water intake in dairy cow

Why is water quality important for dairy cows?

Water quality is increasingly recognised as a determinant of dairy cow health, behaviour and productive efficiency. Suboptimal water quality may impair voluntary water intake, feed consumption and milk production, even in the absence of evident clinical signs [1, 6]. Parameters such as salinity, microbial contamination and total dissolved solids can affect both palatability and metabolic responses in dairy cattle [6]. In addition, higher environmental temperatures favour microbial proliferation in drinkers, reinforcing the association between climate conditions, water hygiene and animal welfare [3].

When talking about water quality, this refers to both the water used for cleaning the milking equipment and the water for drinking. If the water is contaminated, it can affect animal health and well-being, and, therefore, this contamination can be transferred to foodstuffs (milk and meat), jeopardising human health. The most common contaminants are microorganisms and their toxins, viruses, protozoa and parasite eggs, as well as pesticides, nitrates, solvents and fuels [9, 11].

It is important to note that water can come from natural sources or from the public supply network and must be of good quality; otherwise, dairy cows may reduce water intake or refuse to drink altogether, consequently reducing food intake. The water used in dairy farms must be colourless and odourless. Water from wells, mines, dams, rivers and lakes is often not suitable for consumption, so it is essential to treat the water properly for later use. Furthermore, water must be frequently subjected to physical-chemical, microbiological and even radioactive analyses [11].

Practical considerations

• Evaluate water hygiene and microbial contamination regularly.
• Clean drinkers more frequently during warm periods.
• Include water quality assessment in herd health protocols.

This shift reflects the growing recognition that acceptable water quality standards do not necessarily guarantee optimal productive performance.

How can water management improve dairy efficiency?

Water management has become a strategic component of dairy production systems under increasing pressure from climate variability and resource scarcity. Efficient management includes monitoring water use, improving distribution systems, maintaining drinker hygiene and optimising water reuse practices within farms [2, 7]. Recent approaches increasingly integrate animal behaviour and precision livestock technologies as indicators of welfare and production efficiency [3, 4]. Monitoring drinking behaviour and drinkers occupancy may help identify early signs of stress, disease or inadequate resource availability [3, 4]. Therefore, efficient water management is becoming essential for improving welfare, sustainability and long-term resilience in modern dairy systems [2, 3, 7].

Practical considerations

• Monitor herd water use routinely.
• Maintain drinkers and distribution systems regularly.
• Include water management in climate adaptation planning.

Behavioural monitoring and precision livestock technologies may become valuable tools for identifying water-related constraints before productivity or welfare is compromised.

The main components of integrated water management in dairy systems are summarised in Figure 1.

Take-Home Messages

• Water is a key, but often overlooked, driver of feed intake, milk yield, and dairy efficiency;
• Climate change is increasing water requirements in high-producing dairy cows;
• Water access directly influences drinking behaviour, welfare and productive performance;
• Water quality affects water intake, animal health and dairy performance;
• Temporary water restriction can alter cow behaviour and compromise comfort;
• Integrated management approaches should combine water requirements, accessibility, quality and behavioural assessment.

References

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[2] Monteiro, A., Santos, S. and Pereira, J.L.S. (2023). Efficient Water Use in Dairy Cattle Production: A Review. The Open Agriculture Journal, Volume 17, e18743315270668. https://doi.org/10.2174/0118743315270668231127190323.

[3] Burkhardt, F.K., Hayer, J.J., Heinemann, C. and Steinhoff-Wagner, J. (2024). Effect of Climatic Condition, Type of Trough and Water Cleanliness on Drinking Behavior in Dairy Cows. Animals, 14, 257. https://doi.org/10.3390/ani14020257.

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[5] Nizzi, E., Dhumez, O., Hurtaud, C. and Boudon, A. (2025). Effect of Temporal Water Restrictions on Drinking Behavior and Time Budget in Lactating Dairy Cows According to Their Position in the Social Hierarchy Within the Herd. Journal of Dairy Science, 108: 1824–1841. https://doi.org/10.3168/jds.2024-25226.

[6] Giri, A., Bharti, V.K., Kalia, S., Arora, A., Balaje, S.S. and Chaurasia, O.P. (2020). A Review on Water Quality and Dairy Cattle Health: A Special Emphasis on High-Altitude Region. Applied Water Science, 10:79. https://doi.org/10.1007/s13201-020-1160-0.

[7] Palhares, J.C.P., Matarim, D.L., Sousa, R.V. and Martello, L.S. (2024). Water Performance Indicators and Benchmarks for Dairy Production Systems. Water, 16, 330. https://doi.org/10.3390/w16020330.

[8] Torres de Campos, A. (2006). Importância da água para bovinos de leite. Embrapa-gado de leite, Brasil. Available: https://www.embrapa.br/gado-de-leite.

[9] Cerqueira, J. Lima. A importância da qualidade da água e da higienização dos bebedouros. AGROS. Available: https://www.agros.pt/artigos/a-importancia-da-qualidade-da-agua-e-da-higienizacao-dos-bebedouros/.

[10] Filgueiras, G. Ingestão de água por bovinos de leite: saiba tudo sobre a importância deste nutriente. PRODAP. Available: https://blog.prodap.com.br/agua-para-bovinos-de-leite/.

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