BOARD-INVITED REVIEW: Quantifying water use in ruminant production1

Abstract

ABSTRACT:The depletion of water resources, in terms of both quantity and quality, has become a major concern both locally and globally. Ruminants, in particular, are under increased public scrutiny due to their relatively high water use per unit of meat or milk produced. Estimating the water footprint of livestock production is a relatively new field of research for which methods are still evolving. This review describes the approaches used to quantify water use in ruminant production systems as well as the methodological and conceptual issues associated with each approach. Water use estimates for the main products from ruminant production systems are also presented, along with possible management strategies to reduce water use. In the past, quantifying water withdrawal in ruminant production focused on the water demand for drinking or operational purposes. Recently, the recognition of water as a scarce resource has led to the development of several methodologies including water footprint assessment, life cycle assessment, and livestock water productivity to assess water use and its environmental impacts. These methods differ with respect to their target outcome (efficiency or environmental impacts), geographic focus (local or global), description of water sources (green, blue, and gray), handling of water quality concerns, the interpretation of environmental impacts, and the metric by which results are communicated (volumetric units or impact equivalents). Ruminant production is a complex activity where animals are often reared at different sites using a range of resources over their lifetime. Additional water use occurs during slaughter, product processing, and packaging. Estimating water use at the various stages of meat and milk production and communicating those estimates will help producers and other stakeholders identify hotspots and implement strategies to improve water use efficiency. Improvements in ruminant productivity (i.e., BW and milk production) and reproductive efficiency can also reduce the water footprint per unit product. However, given that feed production makes up the majority of water use by ruminants, research and development efforts should focus on this area. More research and clarity are needed to examine the validity of assumptions and possible trade-offs between ruminants' water use and other sustainability indicators.

The role of food systems in achieving the sustainable development goals: Environmental perspective

“…This was confirmed by study of Caro et al (2014) (Mekonnen & Hoekstra, 2012). Furthermore, the efficiency of water use was associated with feed production, adopting water conservation management and improved irrigation techniques (Legesse et al, 2017;Legesse et al, 2018). In the current study, through analyzing sustainability reports, it was noticed that companies mainly start with water saving, from streamlining operations and implementing cleaner technologies to recycling and reusing process water.…”

Environmental impacts and future challenges of livestock sector in Hungary

“…In addition, the sector plays a crucial role in deforestation in Latin America and degradation of grasslands in arid areas due to overgrazing [1]. Water use in livestock farming also represents a significant environmental burden, both locally and globally [12]. According to Mekonnen and Hoekstra [13], one kg of beef production requires on average 15 400 litres of water, while 1 kg of sheep production requires 10 400 litres of water, of which feed production accounts for about 99%.…”

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“…This dependence may lead to more active regulation and monitoring of water use, which puts a great amount of pressure, especially financially, on farmers (Robinson et al, 2016). Nowadays studies are estimating water consumption by ruminants, but the efforts are only based on direct water use (Murphy et al, 2014;Fischer et al, 2017;Legesse et al, 2017).…”

“…To evaluate the relationship between dairy production systems and water use, it is necessary to know the consumptive water used in the "feed production-dairy-manure management" chain and to identify the major factors affecting the water consumption for milk production (Lu et al, 2018). Legesse et al (2017) reported that feed production/utilization, best water management practices, and animal production efficiency are strategies to increase the water efficiency of ruminant production.…”