Journal of Cleaner Production 367 (2022) 133062 Available online 8 July 2022 0959-6526/© 2022 Elsevier Ltd. All rights reserved. Impact of summer cooling management on milk water footprint in dairy cows Giampiero Grossi , Andrea Vitali * , Nicola Lacetera Department of Agriculture and Forest Sciences (DAFNE), University of Tuscia, 01100, Viterbo, Italy A R T I C L E INFO Handling Editor: Jian Zuo Keywords: Climate change Global warming Heat stress Cooling DNDC ABSTRACT The Water footprint (WF) is an indicator of the amount of direct and indirect freshwater used to make a product available, measured over its entire supply chain. Dairy cows are cooled using sprinklers and fans to mitigate heat stress (HS) in summer. Although several studies have already evaluated cows’ milk WF, little information is available on the impact of water sprayed to cool cows on milk WF and fans related energy consumption. The study enrolled six Holstein-Friesian farms equipped with cooling systems, including sprinklers and fans. Based on the volume of water sprayed to cool cows, farms were classifed as Low User Spraying Water (Low- USW) and Large-User Spraying Water (Large- USW). For each farm, an alternative no-cooling scenario was modelled considering the water and energy saved, the increment of the drinking water needed from no-cooled cows, and the reduction of milk yield caused by HS. The mean annual WF of the farms involved in the study accounted for 805 ± 225 L water per kg of Fat and Protein Corrected Milk (FPCM) with the following distribution among the green, blue and grey fractions: 67.9%, 21.1%, and 11%, respectively. Cooling operations had a low incidence (0.04%) on the overall milk WF, which was 1.1% lower (8.6 L water kg 1 FPCM 1 ) than that modelled for the alternative no-cooling scenarios. Although both investigated cooling protocols (Large vs Low) showed a similar capacity to contain milk losses during summer, the study has highlighted differences in their resource use. Compared to the Large-USW, the Low-USW cooling management reduces water use by about 0.4 L water kg 1 FPCM 1 and increases energy consumption by about 0.13 kWh kg 1 FPCM 1 . Cooling systems help farmers to mitigate HS in dairy cows during summer. The extra water needed for cooling is compensated by the effects of cooling in limiting the HS-related decline in milk yield. Therefore, the water used to cool cattle does not impact milk’s WF. However, further research is needed to fnd the best solution for sprinklers and fans utilization, optimizing the preservation of animal welfare and environmental sustainability of milk production under climate change scenarios. 1. Introduction The lack of access to adequate quantities of water to simultaneously support both human and ecosystem water needs is increasingly being recognised in many countries as a serious and growing concern (Boretti et al., 2019). Agriculture accounts for about 72% of all water with- drawals and it is the largest consumer of freshwater resources globally (UN-Water, 2021). Dairy products play a signifcant role in the human diet, but at the same time, they are often associated with high envi- ronmental impacts, such as freshwater resource depletion (Miglietta et al., 2021). Over the last decades, climate change has generated multiple pres- sures on livestock and worldwide production systems (Lamastra et al., 2017). One substantial pressure of global warming on livestock animal welfare is the increased risk of heat stress (HS) during the summer season, which is defned as a condition occurring when an animal cannot dissipate an adequate amount of heat to maintain thermal body balance (Carvajal et al., 2021). This condition may prompt physiological and behavioural responses, leading to physiological disorders that nega- tively affect milk production, reproduction, and health of dairy cows (Bernabucci et al., 2014). Although farmers increasingly provide their pens with heat * Corresponding author. E-mail address: vitali@unitus.it (A. Vitali). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro https://doi.org/10.1016/j.jclepro.2022.133062 Received 23 March 2022; Received in revised form 23 June 2022; Accepted 5 July 2022