Glen A. Broderick
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Research Dairy Scientist |
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Research Interests
Nitrogen metabolism in the ruminant. Understanding the factors limiting nitrogen utilization will lead to improved protein efficiency in lactating dairy cows. Poor protein utilization makes it necessary to feed large amounts of protein to high producing dairy cows. Utilization of protein in legumes, the major forages fed to dairy cows in North America, is especially inefficient. This increases feed costs and reduces profits for dairy farmers, contributing to excessive nitrogen excretion and loss to the environment. Approaches include: 1) Quantifying the effects of NPN formation in legume silages and developing ways to reduce silage NPN; 2) developing rapid and accurate methods for quantifying ruminal protein degradation; and 3) developing practical strategies for optimizing the balance between protein degradation and synthesis in the rumen to minimize nitrogen losses to the environment.
Current and Planned Experimentation
- Determining how dietary protein and energy influences protein utilization and nitrogen excretion in the dairy cow.
- Assessing effectiveness of various carbohydrate sources for improving rumen microbial capture of silage NPN.
- Quantifying the contribution of free amino acids and peptides to protein supply from the rumen.
- Testing the value of milk urea as a convenient indicator of protein status of the dairy cow.
- Characterizing the proteolytic activity of rumen microbes and commercial enzymes with the objective of elaborating blends of commercial proteases that mimic the degradative activity of rumen organisms.
Effect of maceration and enzyme treatments on utilization of alfalfa forage by lactating cows.