Gary L. Williams, Ph.D.
Regents Fellow, Faculty Fellow & Professor
Research Leader, Physiology of Reproduction
E-mail: glwilliams@ag.tamu.edu

             Dr. Gary Williams is Professor and Research Leader in the Animal Reproduction Laboratory, Texas AgriLife Research Station-Beeville. He also is a member and former Vice Chair of the Interdisciplinary Faculty of Reproductive Biology, Texas A&M University (TAMU), College Station, and serves on the graduate faculty in Physiology of Reproduction, Department of Animal Science.

             Williams’ basic research interests currently focus on how nutritional status is communicated to the brain in the bovine female during pubertal development and the postpartum period, and on neuroendocrine mechanisms regulating seasonal reproduction in the mare.  Applied research efforts and public outreach involve management systems for fixed-time appointment breeding in Bos indicus-influenced cattle and reproductive management of the beef cow and mare.

            Williams received B.S. and M.S. degrees in Animal Science from New Mexico State University in 1972 and 1975, respectively, and the Ph.D. in Animal Physiology from the University of Arizona in 1978. He is a Diplomate of the American College of Animal Physiology. Williams has served as mentor for 33 M.S., Ph.D. and postdoctoral trainees, lectured nationally and internationally (83 invited presentations), and authored or co-authored over 300 publications.

            Williams has served on the editorial board of three journals and two terms as Associate Editor of the Animal Growth, Physiology and Reproduction section of the Journal of Animal Science. He has received the Monsanto Animal Physiology and Endocrinology Award from the American Society of Animal Science (2004), and Vice Chancellor Awards in Excellence for Team (1990) and Individual (1993) research from the Texas A&M University System. He was named by the latter as Regents Fellow and Texas AgriLife Research Faculty Fellow in 2001 and 2004, respectively.

Recent Publications

Zuluaga, J. F., J. P. Saldarriaga, D. A. Cooper, and G. L. Williams. 2007. Evaluation of vaginal electrical resistance as an indicator of follicular maturity and suitability for timed artificial insemination in beef cows subjected to a synchronization of ovulation protocol. Animal Reproduction Sci. (in press). Available online at: 10.1016/J.anireprosci.s007.10.002 

Zuluaga, J. F. and G. L. Williams. 2007. High-pressure steam sterilization of previously used CIDR inserts enhances the magnitude of the acute increase in circulating progesterone after insertion in cows. Animal Reproduction Sci. (in press). Available online at: 10.1016/j.anireprosci.s007.06.006

 Williams, G. L., M. Amstalden,  G. P. Blodgett, J. E. Ward, D. A. Unnerstall, and K. S. Quirk.  2007. Continuous administration of low-dose GnRH in mares, I. Control of persistent states of anovulation during the ovulatory season. Theriogenology 68: 67-75

Collins, S.M., D. A. Zieba, and G. L. Williams.  2007. Continuous administration of low-dose GnRH in mares, II. Pituitary and ovarian responses to uninterrupted treatment beginning near the autumnal equinox and continuing throughout the anovulatory season. Theriogenology

Zieba D.S, B. Klocek, G. L. Williams, K. Romanowicz, L. Boliglowa, and M. Wozniak. 2007. In vitro evidence that leptin suppresses melatonin secretion during long days and stimulates its secretion during short days in seasonal breeding ewes. Dom. Anim. Endocrinol. 33: 358-365

Saldarriaga, J.P., D. A. Cooper, J. A. Cartmill, R. L. Stanko, and G. L. Williams.  2006. Ovarian, hormonal and reproductive events associated with synchronization of ovulation and timed appointment breeding of Bos indicus-influenced cattle using intravaginal progesterone, gonadotropin-releasing hormone, and prostaglandin F2α. J.Anim. Sci. 85:151-162

Zieba, D., M. Amstalden and G. L. Williams.  2005.  Regulatory roles of leptin in reproduction and metabolism: A comparative review.  Dom. Anim. Endocrinol. 29: 166-185

Amstalden, M., T. E. Spencer, P.G. Harms, D. H. Keisler, and G. L. Williams.  2005. Expression of leptin receptor and suppressor of cytokine signaling-3 genes in adenohypophysis of normal-fed and fasted cows. Reprod. Biol. 5: 237-245

Amstalden, M., P.G. Harms, T. H. Welsh, Jr., R. D. Randel, and G. L. Williams.  2005.  Effects of leptin on gonadotropin-releasing hormone release from hypothalamic-infundibular explants and gonadotropin release from adenohypophyseal primary cell cultures: Further evidence that normally-nourished cattle are resistant to leptin.  Anim. Reprod. Sci.  85: 41-52.

Zieba, D.A., M. Amstalden, S. Morton, M. N. Maciel, D. H. Keisler, and G. L. Williams. 2004. Regulatory roles of leptin at the hypothalamic-hypophyseal axis before and after sexual maturation in cattle.  Biol Reprod. 71: 804-812.

Amstalden, M., Zieba, D.A., M. R. Garcia, R. L. Stanko, T. H. Welsh, Jr., W. H. Hansel, and

G. L. Williams.  2004.  Evidence that lamprey gonadotropin-releasing hormone III does not release follicle-stimulating hormone selectively in cattle.  Reproduction. 127: 35-43.