Maximizing Protein Efficiency in Dairy Production

CRIS # 3655-31000-017-00D

Time-line: September 25, 2002 to September 24, 2007

Personnel:
Scientists: Glen A. Broderick (0.7), Larry D. Satter (0.6), Richard E. Muck (0.4), Ronald D. Hatfield (0.3), Geneticist (open, 0.3), Agricultural Engineer (open, 0.2) Total = 2.5 SY
Technical support: Wendy Radloff (1.0), Fern Kanitz (1.0)
Non-permanent support: Post-doctoral scientist (1); Graduate students (4.0); Undergraduate technicians (1.0 equiv.)

Importance:
Milk is an excellent source of high quality nutrition in the American diet. However, inefficient utilization of dietary N by dairy cows requires that large amounts of protein be fed to dairy cows, increasing farm costs, reducing profits for farmers, and increasing N pollution of the environment. Improving N efficiency and reducing N pollution in dairy production has become a major national priority.

Objectives:
• Developing methods for reducing silage protein breakdown to nonprotein N (NPN).
• Developing rapid and accurate methods for measuring rumen protein degradation.
• Developing practical strategies for optimizing rumen protein degradation and formation.
• Developing practical feeding and cropping approaches to reduce farm importation of fertilizer and feed N.

Projects:
• Developing techniques to reduce excessive NPN formation in legume silage and for improving the usefulness of NPN already present in silages.
• Transfering red clover’s gene for polyphenol oxidase (the enzyme that lowers red clover NPN) to alfalfa; enhancing polyphenol oxidase in red clover using conventional genetic selection.
• Developing rapid, practical lab techniques to measure protein breakdown so N efficiency can be improved through more precise ration formulation.
• Developing feeding strategies to maximize protein efficiency by optimizing the balance between protein breakdown and formation in the cow’s rumen.
• Developing cropping and feeding options, and manure management strategies, to reduce importation of fertilizer and feed N onto the dairy farm to minimize N losses to the environment.

Impact:
Inefficient utilization requires that large amounts of protein be fed to dairy cows, increasing feed costs, reducing farmer profits, and increasing environmental N pollution. Utilization of protein in legume silages, major feeds for dairy cows in North America, is especially poor because of their large amounts of NPN. Dairy farmers have countered this low efficiency by feeding more protein because the value of the extra milk produced was greater than the cost of the extra protein. However, N pollution has now become a major problem in agriculture. The overall objective of this project is to improve protein efficiency and reduce N losses to the environment in dairy farming.