Steven A. Zinn
Department Head and Professor


   Phone: (860) 486-0861


   Office: George White Bldg., Room 108




  • Ph.D. (Animal Science), Michigan State University, 1989
  • M.S. (Animal Science), Michigan State University, 1984
  • B.S. (Animal Science), Cornell University, 1978

Dr. Zinn grew up in Southern New York and received his BS in Animal Science from Cornell University. He then worked as the Research Coordinator at the Cornell Dairy Teaching and Research Unit for 2.5 years. After that, he then received his MS and PhD degrees in Animal Science from Michigan State University. Following completion of a post doc at the Worcester Foundation for Experimental Biology, he joined the faculty of Animal Science at the University of Connecticut in 1990.



Area of Interest

My research interests are tissue-specific expression of growth factors during development in livestock and physiological mechanisms involved in efficiency of animal production. This work focuses primarily on the role of growth hormone (GH). We have focused on the genetic component of GH secretion, especially in response to growth hormone releasing factor (GRF). And if the magnitude of GH secretion can be utilized as a physiological predictor of genetic merit. We are also interested in the physiological role that GH has in milk production, growth, changes in body composition and feed utilization in cattle.

Genetic improvement in dairy cattle has increased rapidly since the development of progeny testing programs which effectively identify superior sires. However, such programs are time-consuming and expensive, since milk production data must be collected on a sire's daughters before an estimate of his genetic merit can be calculated. The total costs are eventually borne by the dairy industry, at an approximate cost of $250,000 per bull desirable enough to join the active list. If alternative methods could be developed which were capable of evaluating genetic merit of dairy sires at a young age, substantial savings would be realized by the entire dairy industry. Growth hormone is involved in regulating energy partitioning, and exogenous GH administration increases milk yield in cows. In mature dairy bulls, GH pulse frequency has been reported to be negatively related to genetic merit for production, but sample size was rather restricted. We have collected data which shows that GRF stimulated greater GH response in superior than inferior sires. The strong possibility exists that GH response to GRF administration in young bulls may be a valuable indicator of genetic merit. The objectives of this project are to determine whether the GH response to a regimen of SRIF and GRF administration can be used to evaluate genetic merit in young dairy bulls, and to investigate the mechanism regulating differential response among bulls of differing genetic merit. To date, we have shown that genetically superior sires treated with growth hormone releasing factor secrete greater amounts of growth hormone than genetically inferior sires. We are currently investigating the genetic influence of somatostatin on growth hormone release in cattle.

Administration of exogenous growth hormone stimulates milk yield in dairy cattle and growth rate in cattle and pigs. We have shown that exogenous GH also stimulates milk production in beef cattle and enhances utilization of feed in growing beef animals. Currently we are investigating the effect on GH administration on insulin-like growth factors and their binding proteins in these growing beef animals. One major problem with the use of GH is the method of delivery. In previous experiments, cattle have been injected on a daily basis. Potential future experiments are to evaluate novel methods of delivery of GH to growing animals.

Classes Taught

ANSC 3194/SAAS 294 Undergraduate Seminar
ANSC 3316 Endocrinology of Farm Animals
ANSC 3317W Scientific Writing in Endocrinology of Farm Animals
ANSC 3691 Professional Internship
ANSC 5616 Endocrinology of Farm Animals
UNIV 1810 Animal Science Learning Community

Awards and Achievements

  • 2019 CVMA Distinguished Service Award
  • 2018 UConn AAUP Career Teaching Excellence Award
  • 2017-2018 - President of the American Society of Animal Science
  • 2017 - USDA Northeast Regional Award for Excellence in College and University Teaching in the Food and Agricultural Sciences
  • 2016 - University Teaching Fellow Award from the Center for Excellence in Teaching and Learning
  • 2016- UConn foundation Alumni Faculty Excellence Undergraduate Teaching Award
  • 2015 - Named an ASAS Fellow in the Administration Category
  • 2015- Named a Top 20 Outstanding Animal Science Professor by
  • 2014 - H. Allen Tucker Lactation and Endocrinology Award
  • 2014 - CPIA Academic Advisor of the Year Award
  • 2011-2015 - Editor and Founder of Animal Frontiers: The Review Magazine of Animal Agriculture
  • 2010-2012 - Served on the Provost's Library Advisory Committee
  • 2008-2014 - Editor-in-Chief of the Journal of Animal Science. This is the premier animal science journal. Previously, he had served as associate Editor of Physiology (2003-2005) and then Division Editor of Growth, Reproduction and Physiology (2005-2008).
  • 2006 - Elected to a two-year term to the President's Athletic Advisory Committee
  • 2003 - College of Agriculture and Natural Resources Research Excellence Award
  • 2002 - UConn Agriculture and Natural Resources Alumni Association Award for Excellence in Teaching
  • 2001 - 2002 First Year Experience Teaching Award
  • 2001 - 2002 - Outstanding Undergraduate Faculty Advisor for the University of Connecticut
  • 1994 - Northeast ADSA/ASAS Young Scientist Award


Pillai, S.M, N.H. Sereda, M. L. Hoffman, E.V. Valley, T. D. Crenshaw; Y.-K. Park; J.-Y. Lee, S.A Zinn and K.E. Govoni. Effects of poor maternal nutrition during gestation on bone development and mesenchymal stem cell activity in offspring. PLOS One 0168382. 87

Hoffman, M. L., S. A. Reed, S. M. Pillai, A. K. Jones, K. K. McFadden, S. A. Zinn and K. E. Govoni. 2017. The effects of poor maternal nutrition during gestation on offspring postnatal growth and metabolism. J. Anim. Sci. doi: 10.2527/jas.2016-1229.

Jones, A. K., R. E. Gately, K. K. McFadden, S. A. Zinn, K. E. Govoni and S. A. Reed. 2017. Ultrasonographic assessment of fetal heart, umbilicus, ribs and placentomes during mid-gestation and the agreement of ultrasound measurement with corresponding postmortem data in the sheep. Reproduction in Domestic Animals doi: 10.1111/rda.12961.

Jones, A. K., M. L. Hoffman, S. M. Pillai, K. K. McFadden, K. E. Govoni, S. A. Zinn and S.A. Reed. 2017. Gestational restricted- and over-feeding promote maternal and offspring inflammatory responses that are distinct and dependent on diet in sheep. Biology of Reproduction. doi: 10.1093/biolre/iox174.

Pillai, S. M., Jones, A. K., Hoffman, M. L., McFadden, K. K., Reed, S. A., Zinn, S., & Govoni, K. 2017. Fetal and organ development at gestational days 45, 90, 135 and at birth of lambs exposed to under- or over-nutrition during gestation. Translation Anim. Sci. 1, 16-25. 10.2527/tas2016.0002

Hoffman, M. L., Reed, S. A., Pillai, S. M., Jones, A. K., McFadden, K. K., Zinn, S., & Govoni, K. 2017. The effects of poor maternal nutrition during gestation on offspring postnatal growth and metabolism. J. Anim. Sci. 94, 3093-3099. 10.2527/jas.2016-1229

Jones, A. K., Gately, R. E., McFadden, K. K., Hoffman, M. L., Pillai, S. M., Zinn, S., Govoni, K., & Reed, S. A. 2017. Ultrasound during mid-gestation: Agreement with physical foetal and placental measurements and use in predicting gestational age in sheep. Reprod. Dom. Anim. 10.1111/rda.12961

Hoffman, M. L., Peck, K. N., Wegrzyn, J., Reed, S. A., Zinn, S., & Govoni, K. 2016. Poor maternal nutrition during gestation alters the expression of genes involved in muscle development and metabolism in lambs. J. Anim. Sci. 94, 3093-9. 10.2527/jas.2016-0570

Zinn, S.A. 2014. H. Allen Tucker Lactation and Endocrinology Award: Graduate Education: Lessons from my mentor. J. Anim. Sci 93: 12: 5594-5596. doi: 10.2527/jas2015-8869

Zinn, A.T., M.D. Foreman, L. Griffin Masso, D.T. Ouimette, S.A. Zinn. 2014. Learning Communities: Animal Science at the University of Connecticut. Natural Sci. Education. DOI: 10.2134/nse2014.09.0021

Reed, S.A., J.S. Raja, M.L. Hoffman, S.A. Zinn and K.E. Govoni. 2014. Poor maternal nutrition inhibits muscle development in ovineoffspring. J. Anim. Sci. Biotech. DOI: 10.1186/2049-1891-5-43.

Zinn, S.A. and A.M. Beck. 2014. The human-animal bond and domestication: Through the ages…animals in our lives. Animal Frontiers 4 (issue 3): 5-6.

Hoffman, M.L., M.A. Rokosa, S.A. Zinn, T.A. Hoagland, and K.E. Govoni. 2014. Poor maternal nutrition during gestation in sheep reduces circulating concentrations of insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3 in offspring. Domest. Anim. Endocrinol. 49:39-48.

McGonagle, A., H.C. Freake, S.A. Zinn, T. Bauerle, J. Winston, G. Lewicki, M. Jehnings, D. Khan-Bureau, and M. Philion. 2014. Evaluation of STRONG-CT: A program supporting minority and first-generation U.S. science students. J. STEM Ed.: Innovat. Res. 15:52-61

Glynn E.R., A.L. Sanchez, S.A. Zinn, T.A. Hoagland, and K.E. Govoni. 2013 Culture conditions for equine bone marrow mesenchymal stem cells and expression of key transcription factors during their differentiation into osteoblasts. J. Anim. Sci. Biotech. 4:40 (DOI: 10.1186/2049-1891-4-40).

Zinn, S.A. 2011. Animal Frontiers: Future prospects for the beef industry. Animal Frontiers 1 (issue 2):1-3.

Zinn, S.A. 2011. Animal Frontiers: The birth of the review magazine of animal agriculture. Animal Frontiers 1 (issue 1):1-2.

Govoni, K.E., D. Goodman, R.M. Maclure L. Penfold, and S.A. Zinn. 2011. Serum concentrations of insulin-like growth factor-I and insulin-like growth factor binding protein-2 and -3 in eight hoofstock species. Zoo Biol. 30: 275-284.

Mazzaro, L.M., J.P. Richmond, M. Kluever, J. Morgan, J.L. Dunn, S.A. Zinn, and E.A. Koutsos. 2010. Evaluation of an alternative to feeding whole frozen fish in Beluga Whales (Delphinapterus leucas). Zoo Biol. 29: 1–20.

Richmond, J.P., T. Jeanniard du Dot, D.A.S. Rosen, and S.A. Zinn. 2010. Seasonal influence on the response of the somatotropic axis to nutrient restriction and re-alimentation in captive Steller sea lions (Eumetopias jubatus). J. Exp. Zool. 313A:144–156, 2010.

Richmond, J.P., T. Norris, S.A. Zinn. 2010. Re-alimentation in harbor seal pups: Effects on the somatotropic axis and growth rate. Gen. Comp. Endocrinol. 165: 286-292.

Richmond, J.P, J. Skinner, J. Gilbert, L.M. Mazzaro, and S.A. Zinn. 2008. Comparison of the Somatotropic Axis in Free-ranging and Rehabilitated Harbor Seal Pups (Phoca vitulina). J. Zoo Wild. Med. 39:342-348.

Velayudhan, B.T., K. E. Govoni, T. A. Hoagland, and S A. Zinn. 2007. Growth rate and concentrations of the somatotropic axis in beef cattle administered exogenous bovine somatotropin beginning at 200, 250 and 300 days of age. J. Anim. Sci. 85:2866-2872.

Sciadone, M.P., L.Yao, M. Schaller, S. A. Zinn and H.C.Freake. 2004. Diethylenetriamine-pentaacetic acid enhances thyroid hormone action by a transcriptional mechanism. Biol. Trace Element Res. 99: 219-232.

Govoni, K.E., T.A. Hoagland and S.A. Zinn. 2004. The ontogeny of the somatotropic axis in Hereford calves from birth to one year of age and its response to administration of exogenous bovine somatotropin. J. Anim. Sci.82:1646-1655.

Govoni, K.E., T.A. Hoagland and S.A. Zinn. 2003. The ontogeny of the somatotropic axis in male and female Hereford calves from birth to one year of age. J. Anim. Sci. 81:2811-2817.

L.H., W. J. Weber, B. A. Crooker, G. W. Kazmer, S. A. Zinn, L. B. Hansen and H. Chester-Jones. 2002. Effects of Selection for Milk Yield on Growth Hormone Response to Growth Hormone Releasing Factor in Growing Holstein Calves. J. Dairy. Sci. 85: 2529-2540.

Rausch, M.I., M.W. Tripp, K.E. Govoni, W. Zhang, W.J. Weber, B.A. Crooker, T.A. Hoagland and S.A. Zinn. 2002. The response of body weight gain, somatotropin, insulin-like growth factor I and insulin-like growth factor binding proteins-2 and -3 to limit feeding and somatotropin supplementation in growing beef cattle. J. Anim. Sci. 80:94-100.

Govoni, K.E., X.C. Tian, G.W. Kazmer, M.T. Taneja, B.P. Enright, A.L. Rivard, X. Yang and S.A. Zinn. 2002. Age-related changes of the somatotropic axis in cloned Holstein cattle. Biol. Reprod. 66:1293-1298.

Freake, H.C., M. Schaller, A. Trzcienski and S.A. Zinn. 2002. Zinc chelation amplifies thyroid hormone action, but has variable effects on zinc efflux in cultured cells. Proc. Nutr. Soc. 61: 47A.

Zinn, S.A., C. Faustman, J.W. Riesen. 1992. Developing Oral Communication Skills in Animal Science Classes. NACTA J. 37:14-17.

Hobbies/Non-Academic Interests

Auto racing


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Department of Animal Science
Unit 4040
17 Manter Road
Storrs, CT 06269-4040

George White Building Room 107
Open Monday – Friday, 8am – 5pm
Phone: (860) 486-2413
Fax: (860) 486-4375