The Effects of Altering the Protein Efficiency of Lactating Dairy Cows on the Whole-Farm Nitrogen Efficiency of Dairy Farms.

Project Overview

Project Type: Research and Education
Funds awarded in 1999: $89,571.00
Projected End Date: 12/31/2003
Region: Western
State: Utah
Principal Investigator:
Allen Young
Utah State University


  • Animals: bovine
  • Animal Products: dairy


  • Animal Production: animal protection and health, manure management
  • Crop Production: nutrient management


    Average whole-farm N balance for dairies in the West was consistent with other studies in that imported feed was the single largest N input and animal products, milk and meat, were the largest source of output. The most important subsystem was how efficiently feed N was converted to product N. Manure handling should not overshadow herd and crop N efficiencies in attempts to improve N balances. Milk urea nitrogen was not a good predictor of whole-farm nitrogen balance because of the inclusion of nonlactating animals in the summary.

    Project objectives:

    1. Verify the accuracy of MUN analysis for predicting nitrogen (N) and the N (protein) metabolism of lactating cows in independent digestion studies.

    2. Determine the potential use of MUN analysis and a recently developed computer worksheet for predicting N losses and whole-farm efficiencies on commercial dairies in UT and ID.

    3. Disseminate all results to agricultural scientists and consultants as well as dairy producers.

    Sub-objectives of the University of Maryland as they relate to the overall project are:

    1) to improve computer worksheets for calculating whole farm balances by adapting them to the Western region and by implementing changes identified by using the worksheets in this region,

    2) to assist with evaluation and improvement in MUN analysis based on research conducted at Utah State University, and

    3) to disseminate information from this project to farmers via extension publications and the World Wide Web.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.