University of Florida

Timothy J. Hackmann, Ph.D.

Dr. Hackmann attempts to improve efficiency of livestock through study of microbes that inhabit the gastrointestinal tract.  Specifically, his program focuses on the microbes of the rumen, their response to excess energy, and their transport of carbohydrates. 
When given a small amount of excess energy, microbes respond by storing the excess energy as glycogen.  However, when given a large or prolonged excess, microbes respond wastefully by burning it off as heat (energy spilling).  By further characterizing these responses to excess energy, along with transport of carbohydrates, Dr. Hackmann aims to maximize efficiency of microbes and that of ruminant livestock in turn. 
Dr. Hackmann has also engaged in the study of forage nutrition, wild ruminant nutrition, and mathematical modeling.

Representative Publications:

Additional Publications @PubMed.Gov

Hackmann, T.J., Diese, L.E., and Firkins, J.L. (2013) Quantifying the responses of mixed rumen microbes to excess carbohydrate. Appl. Environ. Microbiol. 79, 3786-3795.

Hackmann, T.J., Keyser, B.L., and Firkins, J.L. (2013) Evaluation of methods to detect changes in reserve carbohydrate for mixed rumen microbes. J. Microbiol. Methods 93, 284-291.

Hackmann, T.J. (2011) A system for predicting energy and protein requirements of wild ruminants. Zoo. Biol. 30, 165-188.

Hackmann, T.J. and Spain, J.N. (2010) Invited review: ruminant ecology and evolution: perspectives useful to ruminant livestock research and production. J. Dairy. Sci. 93, 1320-1334.

Hackmann, T.J. and Spain, J.N. (2010) A mechanistic model for predicting intake of forage diets by ruminants. J Anim. Sci. 88, 1108-1124.

Hackmann, T.J., Sampson, J.D., and Spain, J.N. (2010) Variability in in situ ruminal degradation parameters causes imprecision in estimated ruminal digestibility. J. Dairy. Sci. 93, 1074-1085.

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Timothy J. Hackmann, Ph.D.
Assistant Professor
Department of Animal Sciences
Ph.D., Ohio State University