Michael Brugger
Ohio State University
Past studies indicate that a dairy cow can require up to 50 gallons of water per day (gpd) for drinking, feed and cleaning, raising concerns about costs and water availability as well as scrutiny from neighbors worried about water usage. To better understand where and how the water is used, OSU collaborated with VMark LLC to monitor water usage on a 540+-cow dairy in northwestern Ohio. The dairy is representative of many in Ohio, utilizing a free-stall barn, milking three times a day, feeding a mixed ration and using an earthen structure for manure storage. Thirteen commercial meters were installed to monitor water usage throughout the system. Data collected January 2005 through December 2005 averaged 20.5 gpd/cow for drinking water (all cows) and 8.3 gpd/cow (lactating cows) for parlor, milking equipment and bulk tank wash water, significantly less than the 40-50 gpd/cow referenced in the literature. Differences are attributed to continuous monitoring rather than measuring only peak flows, seasonal and climatic variations, milking center equipment differences, 6 gpd/cow consumed in feed rations, and a sprinkler system at the monitored dairy used for cooling the cows. The study also found that continuous, multi-point monitoring is an essential tool for managing water use, allowing leaks and other problems to be pinpointed and identifying alternatives to minimize usage. Water used for the plate cooler was reduced from 42 to 21 gallons per minute saving 8 million gallons of water each year with no change in milk temperature. In addition, training of employees to minimize water use during parlor wash down, resulted in a significant reduction in usage. Additional research is being planned to monitor two additional farms for three years to verify the initial data and to develop an alarm system that will activate when water flows are too high or low.
Discussion:
John Smith (OSU) asked where the water used for the plate cooler goes and if the heat from it is captured. Brugger responded that the water is used for drinking water for the cows and that the only heat capture is from the bulk tank cooling compressors.
Smith asked where the wash water goes. Brugger replied that it is routed to the manure storage structure.
Brian Gwin (Wayne Economic Development Council) asked is the ~1,100 gallons per day used during the summer to mist the cows was worth the extra water usage. Brugger noted that the benefits were not quantified, but it appears to be of value. The system increases cow comfort and as much of the water evaporates; the impact on the manure storage is not expected to be significant.
Dianne Shoemaker (OSU) questioned the cost of the system. Brugger responded that to monitor six key points, the cost would be about $15,000, including meters, control head and the computer for recording data.
Richard Moore (OSU) asked how the milking house wastewater is handled. Is it land applied? Brugger responded that the CIP, bulk tank wash water and wash down water goes to the earthen manure storage structure where the sand settles out. The remaining liquids are pumped and land applied.
Shoemaker asked if paper or cloth towels are used in the milking center. Brugger noted they are cloth and suggested that a front loading washer would reduce the amount of water needed for cleaning them.
Jim Skeeles (OSU) questioned the farmers cost for manure handling. Brugger noted that it was not evaluated; however, custom applicators in the area charge $0.02-0.05 per gallon. Pumping costs and transportation would also need to be considered.
Tom Zimmerman (OSU) asked if the cost of the monitoring systems was justified. Brugger responded that the farmer wants to keep the system in place; however, did not have to pay for it. Brugger suggested that the up front investment will result in long term savings that will make it economical. Brugger noted that one outcome of the research is a workshop to be held in Spring 2006 that will focus on operating and maintaining equipment to optimize its use and minimize costs.
Zimmerman asked if the monitoring costs are independent of the size of the dairy. Brugger replied that it is the same as the number of meters and recording equipment do not vary and are the primary costs.
Jim Hocker (OSU) questioned the upkeep costs and expected life span of the meters. Brugger noted that the meters are expected to last 5-10 years, depending on water quality. If service is needed, the meters are designed for easy access to components.
Gene McCluer (OSU) asked about plans to publicize the initial data and results. Brugger is working on a Fact Sheet as well as a manuscript for Dairy Farm Magazine. When available, OCAMM will help disseminate the information.
Moore asked if neighbor’s drinking wells had been monitored during the study. What is the depth to the aquifer? Were there any impacts on nitrate levels? Brugger responded that drinking wells were not monitored, but the additional research would be valuable.
Notes by Mary Wicks
The OCAMM (Ohio Composting and Manure Management) Program is funded by OARDC/OSU.