Models that analyze nutrient flow on a dairy farm indicate that significant improvements in nitrogen utilization can be achieved through feeding management.  Research in nitrogen utilization includes modeling feeding technology and animal grouping as well as developing a means of measuring nitrogen utilization on a dairy farm.  Models indicate that using bovine somatotropin (BST), milking three times daily, and extending daily photo periods will increase nitrogen utilization, resulting in fewer nitrogen losses to the environment.  The impact of grouping animals for feeding has also been modeled.  Feeding for individual needs (rather than the average for the group) would seem to increase utilization of nitrogen.  However, if the uncertainty in predicting nutrient needs as well as uncertainty of the model is accounted for, there appears to be no significant increase in nitrogen utilization.  Field studies to estimate nitrogen utilization on a farm indicate that analyzing milk urea nitrogen (MUN) from bulk tank samples can be effective.  Variations of MUN from the norm may indicate a potential problem in diet formulation, feed analysis, feeding management or animal consumption.

You can find out more about Dr. Kohn’s research by visiting the Maryland’s Manure Net website:  http://www.inform.umd.edu/ManureNet