Water footprint of livestock: comparison of six geographically defined beef production systems

Water use in the livestock sector has featured in the debate about sustainable food systems. Most evidence has come from virtual water calculations which lack impact assessment and adequate consideration of the heterogeneity in livestock production. This study sought new evidence, using a recently developed life cycle impact assessment method for water use to assess six geographically defined beef cattle production systems in New South Wales, Australia, a major production region. The livestock production systems were diverse in farm practice (grass and feedlot finishing), product (yearling to heavy steers), environment (high-rainfall coastal to semi-arid inland) and local water stress. Life cycle inventories were developed from representative farm enterprise budgets. The farm water use inventories sought to describe the impact of the production system on catchment water resources and included irrigation water use as well as the reduction in flows due to the operation of stock dams. The normalised life cycle impact category results for water use, referred to as the water footprint, ranged from 3.3 to 221 L H(2)Oe kg(-1) live weight at farm gate. Due to variation in local water stress, the impact category results were not correlated with the inventory results. The substantial variability in water footprint between systems indicates that generalisations about livestock and livestock products should be avoided. However, many low input, predominantly non-irrigated, pasture-based livestock production systems have little impact on freshwater resources from consumptive water use, and the livestock have a water footprint similar to many broad-acre cereals. Globally, the majority of beef cattle are raised in non-irrigated mixed farming and grazing systems. Therefore, the general assertion that meat production is a driver of water scarcity is not supported.