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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #310319

Title: Using MUN to reduce nitrogen emissions from dairy farms

Author
item Powell, Joseph
item Bocher, Lori

Submitted to: Forage Focus
Publication Type: Popular Publication
Publication Acceptance Date: 5/15/2014
Publication Date: 5/26/2014
Citation: Powell, J.M., Bocher, L.W. 2014. Using MUN to reduce nitrogen emissions from dairy farms. Forage Focus. p. 14-15.

Interpretive Summary:

Technical Abstract: The old adage that you can’t manage what you can’t measure is especially true when it comes to managing nitrogen on a dairy farm. Dairy producers need to manage nitrogen for two main reasons: profitability and pollution abatement. As nitrogen use efficiency improves (cows using more of their feed protein to make milk, not manure), profitability improves. At the same time, there’s a reduction in the amount of nitrogen being lost to the environment. This article summarizes key research findings related to use of the milk urea nitrogen (MUN) assay to enhance feed protein use efficiency and reduce urea nitrogen excretion in urine and nitrogen losses from dairy farms. Approximately half of Wisconsin’s lactating dairy cows are likely fed dietary crude protein in excess of requirements. This is more apt to happen on farms feeding the same ration to all cows and/or farms with more variability in feed quality and management. Highly significant positive relationships were determined between dietary crude protein, MUN, urinary urea and state-wide nitrogen emissions. This implies that an expanded use of MUN as an overall nitrogen management tool may not only enhance dietary nitrogen use efficiency and reduce milk production costs, but also reduce the negative environmental impacts of nitrogen emissions. If the dairy industry developed MUN as a multi-purpose nitrogen management tool, it would offer a relatively straightforward and practical way to move the industry in a positive, cost-effective direction toward abatement of ammonia and nitrous oxide emissions.