Tanya Gressley

Department of Animal and Food Sciences

Tanya Gressley

Associate Dean of Graduate Programs
Professor, Dairy Nutritionist

 302-831-1940

Office location:
531 S. College Avenue
044 Townsend Hall
Newark, DE 19716

Education

  • Ph.D. Dairy Science, University of Wisconsin, 2005
  • M.S. Animal Science, University of Maryland, 1999
  • B.S. Animal Science, University of Maryland, 1997

Primary courses

  • ANFS 112 – Animal Handling Lab
  • ANFS 404 – Dairy Production
  • ANFS 442/642 – Lactational Physiology

Research

Our lab is focused on dairy cattle nutrition and the impact nutrition has on cow health. Current projects include: evaluating the impact of buffers on hindgut starch fermentation, assessing bioavailability and animal performance response to rumen-protected amino acids, and effects of inoculants on silage fermentation.

Journal Articles

Lawrence, M, S. Polukis, A. M. Barnard, M. Miller, L. Kung, Jr., and T. F. Gressley. 2021. Evaluating the impact of Lactobacillus animalis and Propionibacterium freudenreichii on performance and rumen and fecal measures in lactating dairy cows. J. Dairy Sci. In press.

Neiderfer, K. M., A. M. Barnard, K. Z. Moyer, A. M. Trench, A. E. Taylor, S. K. Cronin, and T. F. Gressley. 2020. Effects of calcium carbonate, magnesium oxide, and encapsulated sodium bicarbonate on measures of postruminal fermentation. J. Anim. Physiol. Anim. Nutr. 104:802-811.

Gressley, T. F. and P. L. Ruegg. 2019. Commentary: Advancing completeness and transparency of reporting. J. Dairy Sci. 102:4757-4758.

Aylward, B. A., M. L. Clark, D. S. Galileo, A. M. Barnard, J. R. Wilson, E. Brannick, T. F. Gressley, M. E. Facteau, W. C. Davis, and R. M. Dyer. 2019. Immune cell populations residing in mesenteric adipose depots and mesenteric lymph nodes of lean dairy cows. J. Dairy Sci. 102:3452-3468.

Guiling, M., C. Merrill, L. Kung, Jr., T. F. Gressley, J. H. Harrison, and E. Block. 2017. Effect of source of supplemental fat in early lactation on productive performance and milk composition. Prof. Anim. Sci. 33:680-691.

Gressley, T. F., K. A. Davison, J. Macies, C. Leonardi, M. M. McCarthy, L. M. Nemec, and C. A. Rice. 2016. Effect of abomasal carbohydrates and live yeast on measures of postruminal fermentation. J. Anim. Sci. 94:284-296.

McCarthy, M. M., M. A. Engstrom, E. Azem, and T. F. Gressley. 2013. The effect of an exogenous amylase on performance and total tract digestibility in lactating dairy cows fed a high by-product diet. J. Dairy Sci. 96:3075-3084.

Hengst, B. A., L. M. Nemec, R. R. Rastani, and T. F. Gressley. Effect of conventional and intensified milk replacer feeding programs on performance, vaccination response, and neutrophil mRNA levels of Holstein calves. J. Dairy Sci. 95:5182-5193.

Nemec, L. M., J. D. Richards, C. A. Atwell, D. E. Diaz, G. I. Zanton, and T. F. Gressley. Immune responses in lactating Holstein cows supplemented with Cu, Mn, and Zn as sulfates or methionine hydroxy analogue chelates. J. Dairy Sci. 95:4568-4577.

Gressley, T. F. 2012. Bioactive agents of milk/dairy products. In Encyclopedia of Biotechnology in Agriculture and Food. Taylor and Francis: New York, Published online: 05 Jan 2012; 1-3.

Mainardi, S. R., B. A. Hengst, S. J. Nebzydoski, L. M. Nemec, and T. F. Gressley. 2011. Effects of abomasal oligofructose on blood and feces of Holstein steers. J. Anim. Sci. 89:2510-2517.

Gressley, T. F., M. B. Hall, and L. E. Armentano. 2011. Ruminant nutrition symposium: Productivity and health responses to hindgut acidosis in ruminants. J. Anim. Sci. 89:1120-1130.

Nebzydoski, S. J., S. Pozzo, L. M. Nemec, M. K. Rankin, and T. F. Gressley. 2010. The effect of dexamethasone on clock gene mRNA levels in bovine neutrophils and lymphocytes. Vet. Immunol. Immunopathol. 138:183-192.

Research Abstracts

Smith, M. S, S. K. Cronin, J. Mateos, D. Martinez del Olmo, F. Valdez, and T. F. Gressley. 2020. Evaluating plasma methionine in response to feeding three rumen-protected methionine products. J. Dairy Sci. 103 (Suppl. 1): 304.

Gressley, T. F., I. C. Shivas, H. Leclerc. 2018. Milk and components response of dairy cows when supplemented with a rumen protected B vitamins blend during heat stress. J. Dairy Sci. 101 (E-Suppl. 2):306.

Conklin, M., S. Polukis, A. Barnard, K. Nestor, L. Kung, Jr., and T. F. Gressley. 2018. Evaluating the impact of Bovamine on performance, nutrient digestibility, and digestive function in lactating cows. J. Dairy Sci. 101 (E-Suppl. 2):110.

Barnard, A. M., M. K. Conklin, K. Estes, B. A. Barton, C. Zimmerman, and T. F. Gressley. 2018. Assessing three levels of a rumen-protected methionine prototype on dairy cow performance. J. Dairy Sci. 101 (E-Suppl. 2):90.

Barnard, A. M, M. Conklin, B. Aylward, R. Dyer, R. Arsenault, and T. F. Gressley. 2018. Evaluating the effects of a rumen and hindgut starch challenge on the inflammatory immune response in Holstein cows. J. Dairy Sci. 101 (E-Suppl. 2): 16.

Polukis, S., A. Barnard, T. Gressley, N. Lobos, K. Griswold, and L. Kung, Jr. 2017. Effects of a rumen-protected lysine product as a source of metabolizable lysine for high-producing dairy compared with porcine blood meal. J. Dairy Sci. 100 (E-Suppl. 1): 98

Barnard, A. M, B. A. Barton, C. A. Zimmerman, R. S. Ordway, and T. F. Gressley. 2016. Impact of three rumen-protected lysine prototypes on dairy cow performance, milk composition, and milk casein. J. Dairy Sci. 99 (E-Suppl. 1): 764.

Barnard, A. M, B. A. Barton, C. A. Zimmerman, R. S. Ordway, and T. F. Gressley. 2016. Comparison of three levels of a rumen-protected methionine product on performance of lactating dairy cows. J. Dairy Sci. 99 (E-Suppl. 1): 756.

Barnard, A. M, B. A. Barton, C. A. Zimmerman, R. S. Ordway, and T. F. Gressley. 2016. Impact of a rumen-protected methionine prototype on dairy cow performance, milk composition, and milk casein. J. Dairy Sci. 99 (E-Suppl. 1): 754.

Barnard, A. M., H. Jensen, and T. F. Gressley. 2016. Relationship of days in milk to nutrient digestibility in lactating multiparous cows. J. Dairy Sci. 99 (E-Suppl. 1): 712.