Water use dynamics with conventional and automated milking systems on a dairy farm

An increasing proportion of dairy farms are adopting automated milking systems (AMS). At the same time, the dairy industry is actively exploring strategies to reduce the water footprint of milk production. Automated milking systems have different cleaning procedures than traditional conventional milking systems (CMS), so the effect on water use is a potentially important consideration. Previous studies of AMS approximately a decade ago showed ∼50% more direct water use compared with CMS; however, those studies were based on older technology and compared different farms. The current study measured whole-farm water use partitioned into drinking (for consumption) and service water (for cleaning) on a dairy farm in Eastern Canada. The dairy farm milked 110 to 120 cows initially using CMS and then changing to AMS. Results showed that the pattern of water use changed with the AMS to increased peak drinking water and decreased peak service water use. Cows produced more milk and consumed more water with the AMS. Overall service water use per cow decreased from 30.9 ± 7.7 L·d^-1 with the CMS to 22.5 ± 4.0 L·d^-1 with the AMS, and overall service water use per unit of milk decreased from 0.98 ± 0.25 L·L^-1 with the CMS to 0.68 ± 0.13 L·L^-1 with the AMS. Daily service water use was also more consistent with the AMS (CV = 17.9%) versus the CMS (CV = 24.8%). With the AMS, the farm used significantly more water, produced significantly more milk, and achieved significantly better water use efficiency per liter of milk.