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 Mark D. Hanigan
          Associate Professor
          Department of Dairy Science (0315)
          3310 Litton Reaves Hall
          Virginia Tech
          Blacksburg, VA  24061
 
 Phone: 540-231-0967
 Fax:     540-231-5014
 email:  mhanigan@vt.edu

AREA OF EXPERTISE

Animal Nutrition
Nutrient Metabolism
Metabolic Modeling

ACADEMIC TRAINING

BS        1987           Iowa State University                    Dairy Science
MS       1989           University of California, Davis     Animal Science
PhD      1991           University of California, Davis     Nutrition, minor Physiological Chemistry

PROFESSIONAL EXPERIENCE

1978-1983    Dairy Farm Owner, Denison, Iowa
1987-1991    Graduate Research Assistant, Depts. of Animal Science and Physiological Chemistry, UC-Davis
1991-1993    Post-doctoral Research, Dept. of Biochem. Biophys., UC-Davis
1993-2005    Research Scientist, Dairy, Purina Mills and Land O' Lakes, St. Louis, MO
2005-            Associate Professor, Virginia Polytechnic Institute and State University
 

Professional Affiliations

American Dairy Science Association
American Society of Animal Science
American Society for Nutrition

RESEARCH INTERESTS

Our group's primary interest is the regulation of energy and nitrogen metabolism in the ruminant.  Nitrogen metabolism is of particular interest given the impact of waste nitrogen on the environment.  Efforts to better understand regulation of nitrogen metabolism should lead to improvements in the efficiency of nitrogen use.  Any such improvements will result in reductions in urinary nitrogen output which will reduce ammonia emissions from manure.

We are currently working at the animal level to examine requirements for ruminally degradable protein.  Observations in the literature suggest that current requirements may be excessive.  If true, dietary protein could be reduced which would lead to reductions in urinary nitrogen output and ammonia emissions from housing and manure storage facilities.

As milk protein synthesis is the desired route for nitrogen use, we are also exploring the regulation of protein synthesis in mammary tissue.  Endocrine signals such as insulin and insulin-like growth factor I are thought to regulate milk synthesis.  However, a shortage of amino acids can negate the effects of these signals.  Thus there must be some integration of endocrine and substrate supply signals within the udder.

Data collected are integrated using models of pathway, tissue, and whole animal metabolism.  These models provide a means to interpret and extend the experimental observations.  The collection of high-throughput observations of transcription, translation, post-translational modifications, and metabolism require the use of sophisticated data collation and analytical tools.  This lower-level information can be integrated with animal information utilizing modeling techniques allowing one to translate gene and protein expression data into knowledge of whole animal function.

Tissue and whole animal models can be used to explore the effects of various dietary treatments and identify key components defining metabolic responses.  These components can then be distilled and incorporated into software to be used by industry for balancing rations on farm.  We hope to use data collected from our experimental efforts to improve current metabolic models and use those to define new nutrient supply and requirement equations for industry use.

Current Group Members

Chris Umberger; B.S., Virginia Tech; Laboratory Technician
Agustin Rius; B. VSc., Argentina; M.S., Univ. of Illinois; Ph.D. student
Joby Cyriac; B. VSc., India; M.S., South Dakota State; Ph.D. student
Ashley Elgin; Undergraduate student
Greta Moyer; Undergraduate student
Megan Meyer; Undergraduate student
John Fisher; Undergraduate student