Using Milk Urea Nitrogen as a Nutritional and Environmental Decision-Making Tool to Improve Dairy Sustainability

Commodities

• Animals: bovine

Practices

• Animal Production: feed management

Dairy operations face increasing concerns about environmental
pollution caused by nitrogen excretion from dairy cattle. The
mitigation of the environmental impact associated with dairy
farming can be achieved by ensuring that cows receive an
appropriate amount of protein for efficient milk production. Milk
urea nitrogen (MUN) is a valuable tool for monitoring dietary
protein and nitrogen excretion. However, the interpretation of
MUN values is constrained by its high variability, which is
attributed to a wide range of factors that are not
comprehensively elucidated. This proposal aims to refine the use
of MUN as a decision-making tool to enhance nitrogen utilization
efficiency in dairy cows and reduce the environmental impact of
dairy farming. We will collect data over two years from three
dairy farms in Idaho and one in Utah to determine the
relationships between MUN and animal characteristics, production,
and diet composition. Subsequently, we will derive
computer-assisted mathematical models to relate MUN and animal,
production, and diet parameters. Our study will also quantify how
changes in MUN are associated with economic and environmental
outcomes. To evaluate the impact of environmental factors, such
as heat stress and wildfire smoke, on MUN variability, controlled
experiments will be conducted over two years at the University of
Idaho Dairy Center. Our educational plan includes implementing
the Pacific Northwest Dairy Nutrition Practices School (PNW-DNPS)
to educate producers, nutritionists, feeders, mid-herd managers,
students, and other professionals about the importance of good
feeding management practices for delivering an effective
nutrition program. Furthermore, we will disseminate information
about using MUN as a decision-making tool through traditional
outreach methods and various media formats, targeting
professionals involved in dairy nutrition and advising producers.
To facilitate the practical application of our research, we will
develop a user-friendly web-based tool called MUNTune, which
integrates the derived equations to monitor MUN on dairy farms.
Model adequacy will be evaluated using an independent database
from published studies. By refining the use of MUN as a
decision-making tool, dairy farmers can enhance nutrient
utilization, reduce environmental impact, and promote the
long-term viability of dairy farming practices. This proposal
will contribute to the sustainability of the dairy industry by
improving protein efficiency, achieving cost savings, and
reducing nitrogen excretion.

1) Derive MUN equations based on on-farm data and quantify
economic effects on MUN of varying animal, production, and diet
characteristics; 2) Evaluate the effect of the environment on the
variability of MUN in dairy cows; 3) Develop and deliver the
Pacific Northwest Dairy Nutrition Practices School (PNW-DNPS); 4)
Disseminate information and educate the public about the use of
MUN as a decision-making tool to enhance nitrogen efficiency of
dairy cows; 5) Develop a mobile-friendly web-based tool (MUNTune)
for producers and nutritionists to help them monitor the diet of
dairy cows, given their site-specific characteristics.