1. Rick Kohn Louise Lawrence A program to improve dairy herd nutrition using milk urea nitrogen Department of Agriculture

2. Overview Background Background Project overview Project overview Experience so far Experience so far

3. Milk Urea Nitrogen

4. Nitrogen Metabolism Kohn, et al., 1997. MD Nutrition Conference

5. Implications Milk urea is proportional to blood urea. Milk urea is proportional to blood urea. Milk urea is proportional to amount of excess amino acids and ammonia absorbed. Milk urea is proportional to amount of excess amino acids and ammonia absorbed. High milk urea indicates that more than enough N was absorbed into the body. High milk urea indicates that more than enough N was absorbed into the body. Low milk urea indicates that too little N was absorbed. Low milk urea indicates that too little N was absorbed.

6. Urine N vs. MUN Jonker, et al., 1998. J. Dairy Science

7. Nutrient Balance in a Cow Intake Milk Waste

8. Target MUN MUN Target Concentrations for Holstein Cows

9. Target vs. Observed MUN Jonker, et al., 1999. J. Dairy Science

10. Lab Differences Foss 4000 NIRS is not as repeatable as wet chemistry or Foss 6000. Foss 4000 NIRS is not as repeatable as wet chemistry or Foss 6000. After Sep. 17, 1998 MUN analyses were reduced about 4 units. After Sep. 17, 1998 MUN analyses were reduced about 4 units.

11. Target MUN Kohn et al., 2002. J. Dairy Science

12. Check List ✓ Milk Production ✓ Feed intake ✓ Diet Formulation ✓ Feed Analysis ✓ Feed Digestibility ✓ Feeding Management ✓ Feeding Behavior

13. Typical Results Best

14. Study on feeding in Chesapeake Bay Watershed Surveyed and sampled 450 farms in region Surveyed and sampled 450 farms in region Used milk analysis and survey results to predict N intake, N in urine, N in feces, and N utilization efficiency. Used milk analysis and survey results to predict N intake, N in urine, N in feces, and N utilization efficiency. Jonker, et al., 2002, J. Dairy Science

15. Effect of milk per cow on N utilization efficiency Jonker, et al., 2002, J. Dairy Science

16. Effect of intake N on N utilization efficiency Jonker, et al., 2002, J. Dairy Science

17. Cost of Overfeeding Protein Jonker, et al., 2002. J. Dairy Sci.

18. Environmental Cost of Overfeeding Protein Jonker, et al., 2002. J. Dairy Sci.

19. Project Goal Institutionalize MUN analysis in Maryland and Virginia (and the country). Institutionalize MUN analysis in Maryland and Virginia (and the country).

20. Participants University of Maryland University of Maryland –Coordination, Quality Control, Teaching, Trouble Shooting, Evaluation Maryland Department of Agriculture Maryland Department of Agriculture –Coordination Virginia Tech Virginia Tech –Teaching, Trouble Shooting Milk Cooperatives Milk Cooperatives –Information disemination Milk Analysis Laboratories Milk Analysis Laboratories –Analysis

21. Barriers to Use of MUN Inconvenience of sampling and analysis Inconvenience of sampling and analysis Inconsistent analysis results Inconsistent analysis results Lack of understanding of MUN results Lack of understanding of MUN results Lack of incentive to decrease MUN Lack of incentive to decrease MUN

22. Methods Upgrade milk processor labs to enable routine, accurate analysis of MUN Upgrade milk processor labs to enable routine, accurate analysis of MUN Quality control of MUN analyses Quality control of MUN analyses Education to nutritionists and farmers Education to nutritionists and farmers Provide one-time incentive payments to farmers maintaining low MUN Provide one-time incentive payments to farmers maintaining low MUN

23. Incentives Nominal payment ($100-150) for MUN below target (11 mg/dl) for 3 months Nominal payment ($100-150) for MUN below target (11 mg/dl) for 3 months Publication (with permission) of the names of the 10 top producers per county for high milk yield with low MUN. Publication (with permission) of the names of the 10 top producers per county for high milk yield with low MUN.

24. Experience So Far Presentations and Interviews Presentations and Interviews –Agents, Farmers, Nutritionists, MASCD Contracts with co-ops and labs Contracts with co-ops and labs Laboratory upgrades Laboratory upgrades