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.