Education
- Ph.D., The Ohio State University (Animal Sciences, 2007)
- M.S., University of Florida (Animal Sciences, 2003)
- B.S., University of Missouri (Animal Sciences, 2001)
Research Interests
- Determining the impact of endocrine status and follicular dynamics on oocyte viability and embryonic development in cattle.
- Optimizing estrous synchronization and artificial insemination protocols in beef cattle.
- Understanding the role of diet and specific dietary nutrients on reproductive function, fertility, and developmental programming in cattle.
Outreach
- Reproductive Management of Beef Cattle. The beef industry in Minnesota is diverse in both size of operations and progressiveness of the operator in adopting new technologies and management strategies. Given this diversity, and to assist all producers regardless of scope of their operation, Dr. Bridges has developed three key areas to focus his beef cattle extension programming; 1) providing producers with information on sound reproductive management practices, 2) developing and implementing management strategies to reduce input costs while maintaining reproductive efficiency, and 3) relaying information on the benefits of adapting progressive reproductive technologies and management practices such as estrous synchronization and artificial insemination.
Affiliations
- American Society of Animal Science
- Gamma Sigma Delta; Professional Agricultural Fraternity
- Society for the Study of Reproduction
- Sigma Xi
- NC-1038: “Methods to Increase Reproductive Efficiency in Cattle”
Publications (2006-2010)
- Refereed
Articles -
Bridges, G.A., M.L. Mussard, C.R. Burke, and M.L. Day. 2010. Influence of length of proestrus on fertility and endocrine function in female cattle. Anim. Reprod. Sci. 117:208-215.
Portillo, G.E., G.A. Bridges, J.W. de Araujo, M-K.V. Shaw, F.N. Schrick, W.W. Thatcher, and J.V. Yelich. 2008. Response to GnRH on day 6 of the estrous cycle is diminished as the percentage of Bos indicus breeding increases in Angus, Brangus, and Brahman x Angus heifers. Animal Reprod. Sci. 103:38-51.
Bridges, G.A., L.A. Helser, D.E. Grum, M.L. Mussard, C.L. Gasser, and M.L. Day. 2008. Decreasing the interval between GnRH and PGF2α from 7 to 5 days and lengthening proestrus increases timed-AI pregnancy rates in beef cows. Theriogenology 69:843-851.
Gasser, C.L., G.A. Bridges, M.L. Mussard, D.M. Dauch, D.E. Grum, J.E. Kinder, and M.L. Day. 2006. Induction of precocious puberty in heifers III: Hastened reduction of estradiol negative feedback on secretion of luteinizing hormone. J. Anim. Sci. 84:2050-2056.
- Non-refereed
Articles -
Lemenager, R., A. Bridges, M. Claeys, and K. Johnson. 2009. Spring Pastures – Grass Tetany and Bloat. Available at: www.ansc.purdue.edu/beef/articles/GrassTetanyBloat.pdf
Lemenager, R., M. Claeys, A. Bridges, and K. Johnson. 2008. Managing the cow herd during tough economic times. Available at: www.ansc.purdue.edu/beef/articles/CowHerdToughTimes.pdf
Bridges, A., and R. Lemenager. 2007. Impact of body condition at calving on reproductive productivity in beef cattle. Available at: www.agry.purdue.edu/forage-shortage/BCSandReproduction.pdf.
- Extension Publications -
Bridges, A., R. Lemenager, P. Gunn, M. Claeys. 2010. Using estrous synchronization and artificial insemination to increase profitability in your beef herd. Purdue Extension Publication AS-600-W.
Bridges, A., R. Lemenager, B. Richert, and M. Schutz. 2010. Zearalenone concerns in reproducing livestock. Purdue Extension Publication AS-598-W.
Pezzanite, L., A. Bridges, M. Neary, and T. Hutchens. 2010. Breeding soundness examination of rams and bucks. Purdue Extension Publication AS-599-W.
Bridges, A., S. Lake, R. Lemenager, M. Claeys, and K. Culp. 2009. Cost-effective timed-AI options for beef cows. Purdue Extension Publication AS-594-W.
Bridges, A., S. Lake, R. Lemenager, M. Claeys, P. Gunn, and K. Culp. 2009. Choosing an estrous synchronization programs for replacement beef heifers. Purdue Extension Publication AS-592-W.
Bridges, A. 2008. Recombinant Bovine Somatotropin (rBST) and reproduction in dairy cattle: Reproductive strategies to overcome the loss of rBST in the dairy herd. Purdue Extension Publication AS-589-W.
Bridges, A., S. Lake, R. Lemanager, and M. Claeys. 2008. Non-pregnant cows are non-productive cows. Purdue Extension Publication AS-586-W.
Bridges, A., S. Lake, R. Lemenager, and M. Claeys. 2008. Timed-AI in beef cows: What are your options? Purdue Extension Publication AS-575-W.
- Abstracts -
Bridges, G.A., B.L. Sparks, P.J. Gunn, and K.S. Fisher. 2010. Impact of reduced progesterone during the follicular wave on ovulatory follicle diameter and progesterone concentrations in the subsequent estrous cycle. Abstr. M34. Presented at the 8th International Ruminant Reproduction Symposium, Sep. 3-7, 2010, Anchorage, AK.
Cruppe, L.H., L.A. Souto, M. Maquivar, P. Gunn, M.L. Mussard, D. Wolfenson, A.V. Pires, G.A. Bridges, and M.L. Day. 2010. Use of two coincident doses of PGF2α with the 5-d CO-Synch + CIDR estrous synchronization program. J. Anim. Sci. 88 (Suppl. 1): Abstr. 849.
Fisher, K.S., T.S. Stewart, P.H. Purdy, H.D. Blackburn, W.L. Singleton, B.L. Sparks, P.J. Gunn, and G.A. Bridges. 2010. Reproductive performance of sows inseminated with various doses of frozen-thawed semen. J. Anim. Sci. 88 (Suppl. 1): Abstr. 991.
Sparks, B.L., S.L. Lake, J. Berry, K. Heaton, R.P. Lemenager, L.A. Horstman, K.S. Fisher, P.J. Gunn, and G.A. Bridges. 2010. Effect of PGF2α administration at CIDR insertion on AI pregnancy rates in beef heifers. J. Anim. Sci. 88 (Suppl. 1): Abstr. 845.
Bridges, G.A., N.C. Amyes, M.C. Berg, M.J. D’Occhio, C.A. Morris, and M.L. Day. 2009. Impact of long-term genetic selection for age at puberty on postpartum reproductive physiology in cows. J. Anim. Sci. 87 (Suppl. 1): 689.
Bridges, G.A., M.L. Mussard, L.A. Helser, and M.L. Day. 2009. Comparison of follicular dynamics and hormone concentrations between the 7 d and 5 d CO-Synch + CIDR program in two-year old beef cows. J. Anim. Sci. 87 (Suppl. 1): 464.
Culp, K.C., S.L. Lake, R.P. Lemenager, M.C. Claeys, P.J. Gunn, M. Van Emon, R.P. Aria, and G. A. Bridges. 2009. Efficacy of the 5 day CO-Synch estrous synchronization protocol with or without the inclusion of a CIDR in beef cows. J. Anim. Sci. 87 (Suppl. 1): 466.
Gunn, P.J., K.C. Culp, S.L. Lake, R.P. Arias, R.P. Lemenager, K. Heaton, and G.A. Bridges. 2009. Comparison of the CIDR Select and 5 day CO-Synch + CIDR protocols for synchronizing estrus in beef heifers. J. Anim. Sci. 87 (Suppl. 1): T217.
Souto, L.A., M. Maquivar, M.L. Mussard, G.A. Bridges, D.G. Grum, and M.L. Day. 2009. Fertility and luteal regression with the 5-d CIDR synchronization programs in postpartum beef cows using differing luteolytic treatments. J. Anim. Sci. 87 (Suppl. 1): 465.
Bridges, G.A., M.L. Mussard, D.E. Grum, L.A. Helser, C.L. Gasser, D.M. Dauch, J.L. Pate, and M.L. Day. 2006. The influence of preovulatory estradiol concentrations on uterine function in beef cattle. J. Anim. Sci. 84 (Suppl. 2) 101: Abstr. 207.
Bridges, G.A., M.L. Mussard, L.A. Helser, D.E. Grum, D.M. Lantz, T.L. Ott, J.L. Pate, and M.L. Day. 2006. Effect of preovulatory estradiol concentrations on conceptus and uterine development. p. 91, Abstr. 90. Presented at the 7th International Ruminant Reproduction Symposium, Aug. 13-17, 2006, Wellington, NZ.
Helser, L.A., G.A. Bridges, D.E. Grum, M.L. Mussard, C.L. Gasser, D.M. Lantz, and M.L. Day. 2006. Effect of decreasing the interval from GnRH to PGF2a and lengthening proestrus on reproductive performance in GnRH-CIDR- PGF2a synchronization programs. J. Anim. Sci. 84 (Suppl. 1) 432.
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