Brief Summary of Minutes of Annual Meeting

Steven R. Alm (stevealm@uri.edu) - University of Rhode Island;
Paul Backman (pbackman@psu.edu) - Pennsylvania Agricultural Experiment Station;
Mark J. Carroll (mc92@umail.umd.edu) - University of Maryland;
J. Marshall Clark (jclark@ent.umass.edu) - University of Massachusetts;
Bruce B. Clarke (clarke@aesop.rutgers.edu) - Rutgers University;
Richard S. Cowles (rcowles@caes.state.ct.us) - Connecticut Agricultural Experiment Station;
J. Scott Ebdon (sebdon@pssci.umass.edu) - University of Massachusetts;
Steven Fales;
Karl Guillard (karl.guillard@uconn.edu) - University of Connecticut;
Richard J. Hull (rhu6441@postoffice.uri.edu) - University of Rhode Island;
Noel Jackson;
Peter J. Landschoot (pj11@psu.edu) - The Pennsylvania State University;
Pim Larsson-Kovach (il11@cornell.edu) - Cornell University;
James Lin - USEPA;
Bill Meyer (wmeyer@aesop.rutgers.edu) - Rutgers University;
Kevin Morris - NTEP;
Bridget Ruemmele (bridgetr@uri.edu) - University of Rhode Island;
Mike Sullivan (senmike@uriacc.uri.edu) - University of Rhode Island;
Patricia Vittum (pvittum@ent.umass.edu) - University of Massachusetts

1) Objective 1 (Examine naturally occurring patterns of development and function of the preovulatory follicle for their effects on oocyte maturation, fertilization, and embryo survival) and Objective 3a (Does location of the CL affect follicle development?) have been completed and the results have important implications for our understanding of fertility/infertility in cattle. The results support the hypothesis that in natural cycles ovulation of the dominant follicle of the second wave of the estrous cycle results in significantly lower fertility (pregnancy rate) than ovulation of the dominant follicle of the third wave. However, there was no relationship between location of the previous CL relative to the ovulatory follicle and pregnancy rate. Other studies conducted as part of Objective 1 are providing increased understanding of the changes that occur in persistent dominant follicle in terms of both endocrine function and oocyte development.

2) Progress is being made on Objective 2 (Compare naturally occurring and induced differences in metabolism for their effects on oocyte maturation, fertilization and embryo survival). Experiments under Objective 2a have shown that drenching cattle with propylene glycol results in an extension of the life span of the corpus luteum; this is associated with transient increases in plasma insulin, but not plasma IGF-1. Experiments under Objective 2b have revealed dose-related effects of insulin on steroid secretion by cultured pieces of follicle wall. In other experiments prepartum fat supplementation was associated with an increased postpartum pregnancy rate, in the absence of any significant effect on any metabolic, hormonal, or follicular parameter analyzed.

3) Objective 3b (Do increased or decreased concentrations of systemic progesterone affect follicle development and subsequent fertility?) has proven difficult to accomplish because the methods used to reduce circulating progesterone have not worked as they were reported to. One further attempt at reducing luteal progesterone levels to assess affects on fertility will be made during the next year.


Future Meeting:
Location and Date: Cornell University, October 8-9, 2001
Responsible Individuals: Ron Butler/Joanne Fortune

Connecticut

Milvae RA. 2000. Inter-relationships between endothelin and prostaglandin F2a in corpus luteum function. Rev Reprod. 5: 1-5.

Meidan R, Milvae RA, Weiss S, Levy N, Friedman A. 1999. Intraovarian regulation of luteolysis. J Reprod Fertil Suppl; 54:217-228.

Hinckley RMT. 2000. Endothelin-1, a mediator of ovine luteal function. Ph.D. Dissertation, University of Connecticut.

New Hampshire

Olson KK, Townson DH 2000 Prolactin-induced expression of intercellular adhesion molecule-1 and the accumulation of monocytes/macrophages during regression of the rat corpus luteum. Biol Reprod 62:1571-1578.

Olson KK, Townson DH 2001 Actions of Prostaglandin F2a and Prolactin on Intercellular Adhesion Molecule-1 Expression and Monocyte/Macrophage Accumulation in the Rat Corpus Luteum. Biol Reprod (Accepted)

Olson KK 2000. The effects of prostaglandin F2a and prolactin on immune cell recruitment during regression of the rat corpus luteum. M.S. Thesis, University of New Hampshire.

New York

Beam, S.W. and W.R. Butler. Effects of energy balance on follicular development and first ovulation in postpartum dairy cows. In Reproduction in Domestic Animals IV, W.W. Thatcher, E.K. Inskeep, G.D. Niswender, and C. Doberska, eds. J. Reprod. Fertil. Suppl. 54:411-424. 1999.

Butler, W.R. Nutritional interactions with reproductive performance in dairy cattle. Anim. Reprod. Sci. 60-61:449-457. 2000

Butler, W.R. Nutritional effects on resumption of ovarian cyclicity and conception rate. BSAS Symposium on Fertility in the High-Producing Dairy Cow, September 20-22, Galway, Ireland. pp. 13-14. 2000.

Frajblat, M. and W.R. Butler. Metabolic effects of insulin and IGF-I in bovine ovarian follicle wall culture. Biol. Reprod. 62(Suppl. 1):222. 2000.

Frajblat, M. and W.R. Butler. Use of bovine ovarian follicle wall in a culture system to study long-term steroidogenesis. J. Dairy Sci. 83(Suppl. 1):211. 2000.

Bode, M.L., R.O. Gilbert, and W.R. Butler. Effects of urea infusion on uterine luminal pH, prostaglandins and proteins in lactating dairy cows. J. Dairy Sci. 83(Suppl. 1):212. 2000

Fortune, J.E. and G.M. Rivera, 1999. Persistent dominant follicles in cattle: basic and applied aspects. Arquivos da Faculdade de Veterinaria UFRGS v. 27 (Suppl.): 24-36.

Rivera, G.M., T.L. Kimmich, and J.E. Fortune, 2000. Steroidogenesis by theca cells of persistent vs. control bovine follicles: androstenedione secretion in response to LH. Theriogenology 53:380.

Fortune, J.E., C.M. Komar, J.S. Tabb, and A.K. Voss, 2000. Ovarian oxytocin: periovulatory production and effects. In: Ovulation: Evolving Scientific and Clinical Concepts, E.Y. Adashi (ed.). Springer Verlag, New York, (in press).

Fortune, J.E., G.M. Rivera, and C.M. Komar, 2000. Selection and differentiation of dominant ovarian follicles in cattle. In: BR Monographs of Reproduction & Catalog Group 2000, A.A.M. Rosa e Silva (ed.). (in press).

Ohio

Bove, S.E., Petroff, M.G., Nishibori, M. and Pate, J.L. 2000. Macrophage migration inhibitory factor in the bovine corpus luteum: Characterization of steady-state messenger ribonucleic acid expression and immunohistochemical localization. Biol. Reprod. 62:879-885.

Marin-Guzman, J., Mahan, D.C. and Pate, J.L. 2000. Effect of dietary selenium and vitamin E on spermatogenic development in boars. J. Anim. Sci. 78:1527-1543.

West Virginia

Sayre, B.L., R. Taft, E. K. Inskeep and J. Killefer. 2000. Increased expression of insulin-like growth factor binding protein-1 during induced regression of bovine corpora lutea. Biol. Reprod. 63:21-29.

Hernandez-Fonseca, H. J., B.L. Sayre, R.L. Butcher and E. K. Inskeep. 2000. Embryotoxic effects adjacent and opposite to the early regressing bovine corpus luteum. Theriogenology 54: 83-91.

Bridges, P.J., D.J. Wright, W.I. Buford, N. Ahmad, H. Hernandez-Fonseca,
M.L. McCormick, F.N. Schrick, R.A. Dailey, P.E. Lewis and E.K. Inskeep. 2000. Ability of induced corpora lutea to maintain pregnancy in beef cows. J. Anim. Sci. 78:2942-2949.

Bridges, P.J., R. Taft, P.E. Lewis, W.R. Wagner and E.K. Inskeep. 2000. Effect of the previously gravid uterine horn and postpartum interval on follicular diameter and conception rate in beef cows treated with estradiol benzoate and progesterone. J. Anim. Sci. 78:2172-2176.