Supplementary use of water study

Published 19 May 14

In a previous study, Cranfield University modelled the volumetric water consumption of British milk. This estimated the quantity of water consumed per kg of fat and protein corrected milk (FMCP) for five different milk production systems, distinguishing between direct (ie ‘blue’) water consumption, predominately resulting from drinking and cleaning routines, and virtual (ie ‘green’) water used to grow forage and concentrate feedstuffs

This supplementary study collected water use data on 11 commercial farms, making comparisons of metered water use with that estimated using a) a commercial water foot printing tool (Water Footprint Tool, E-CO2 Project) and b) the original Cranfield methodology.

In 10 herds following a grazing system, average metered water (per litre FPCM) was 4.3 L. This compared with estimated total consumption of 5.3 L and 6.7 L for the WFT and Cranfield models respectively. Average figures for water consumed in drinking were calculated to be 4.65 L and 4.17 L, for the WFT and Cranfield models respectively. For the fully housed herd, metered water consumption was 5.3 L, compared with estimated figures of 5.4 L and 5.4 L, for WFT and Cranfield models respectively.