According to the World Economic Forum, the water crisis ranks among the top ten most likely global risks (WEF 2015). Nowadays, agriculture consumes 72% of the world's water withdrawals (WAF, 2024), and livestock production accounts for 29% of the water used in agriculture (Heinke et al., 2020). Dairy cow production represents 19% of the water withdrawals by animal production (Mekonnen and Hoekstra, 2012), and it is estimated that this sector is responsible for 4% of global water withdrawals. Furthermore, the population explosion facing the contemporary world, leading to an increase in food demand, could significantly increase the demand for water for agricultural purposes and exceed the available sources of potable water.
In the dairy industry, every aspect of farm management is crucial to ensure the health, welfare, and productivity of the animals. Among these elements, water plays a central role. Although sometimes overlooked compared to other aspects such as feeding, water remains an essential element for the success of any dairy operation. Indeed, of the total amount of water used in the provision of all food products, only 1% is used as drinking water versus 98% for the production of feed for livestock (Hoekstra, 2012).
This article focus on the importance of water in the diet of dairy cows, the impact of farming these animals on water consumption, and explore sustainable methods to minimize the water footprint of dairy farming.
The Critical Role of Water in Dairy Farming
Hydration and Animal Health
Water is a vital element for life and plays a crucial role in the health and well-being of dairy cows. Research by experts in animal science and veterinary medicine has shown that adequate hydration is essential for maintaining the physiological functions of cattle, including digestion, thermoregulation, and milk production (Holter & Urban, 1992; Cardot et al., 2008). According to studies, cows can drink up to 100 liters of water per day, particularly during periods of intense heat or lactation (Lanham et al., 1986; Cardot et al., 2008). About 80% of the water consumed by a cow is used for hydration and the maintenance of normal physiological processes (Holter & Urban, 1992). Insufficient water intake can lead to serious health issues in cows, including dehydration, metabolic disorders, and a decrease in milk production (Burgos et al., 1959). Severe dehydration, reaching 15%, can be fatal (Beede, 2012). Therefore, farmers must ensure constant access to clean and fresh water for their animals. Recent studies have also highlighted the importance of water quality, revealing the harmful effects of contaminated water on cattle health and agricultural production (Bharti et al., 2020; Heinke et al., 2020).
Water Consumption and Feeding
The water consumption of cows is closely linked to their diet. Studies
have shown that the quality and composition of feed can influence the
amount of water consumed by the animals (Banhazi et al., 2019). For
example, high-fiber diets generally require more water to aid digestion
(Banhazi et al., 2019). Moreover, feed rations only cover 20 to 40% of
water needs. The remaining 60 to 80% must be met through drinking water.
Additionally, dairy cows producing milk have increased water
requirements to support their production (Banhazi et al., 2019).
Sustainable Water Management in Dairy Farming
Water management in dairy farming is a significant environmental sustainability issue. According to data collected by agroecology experts, cattle farming is one of the most water-intensive agricultural activities, due to livestock watering and the irrigation of forage crops (Thornton and Herrero, 2020). To ensure the sustainability of this practice, measures are needed to minimize water consumption and reduce waste. Recent research has highlighted the effectiveness of smart irrigation systems and data-driven water management techniques to optimize the use of this limited resource (Pereira et al., 2023). Moreover, the adoption of sustainable agricultural practices such as agroforestry and integrated water resource management helps preserve local ecosystems while ensuring global food security (Thornton and Herrero, 2020). Research by Rotz et al. (2019) has shown that adopting practices such as efficient effluent management, rational use of irrigation water, and the implementation of rotational grazing systems can help reduce the environmental footprint of dairy farming. Furthermore, a balanced diet can optimize water consumption and animal performance (Bauman and Currie, 2018). This approach contributes to maintaining the health and well-being of cows while improving their growth and dairy productivity.
According to studies conducted by Sraïri et al. in 2007 on the valuation of irrigation water by dairy cattle farming in the Tadla perimeter in Morocco, the authors determined the water-to-forage and then forage-to-milk and meat conversion efficiencies. On average, it takes about 1.5 m3 of water per kg of milk and 42 m3 of water per kg of live bovine weight. Case studies, like the "Mazawa Zaidi" project in Kenya and Tanzania, demonstrate the effectiveness of such approaches in improving dairy productivity while conserving water.
In conclusion, water management in dairy farming is a critical issue that requires awareness and concrete actions to ensure the sustainability of our food systems. It is vital to adopt a balanced water management approach that meets the needs of dairy cows while addressing current ecological challenges.