Source: MICHIGAN STATE UNIV submitted to
THE IMPACT OF VARIATION IN FSH SECRETION DURING FOLLICULAR WAVES ON DOMINANT FOLLICLE FUNCTION IN CATTLE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0210556
Grant No.
2007-35203-18178
Project No.
MICL08403
Proposal No.
2007-01289
Multistate No.
(N/A)
Program Code
41.0
Project Start Date
Sep 1, 2007
Project End Date
Aug 31, 2010
Grant Year
2007
Project Director
Ireland, J. J.
Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824
Performing Department
ANIMAL SCIENCE
Non Technical Summary
The mechanisms whereby the high variation in the ovarian reserve (total number of healthy oocytes and follicles in ovaries) may cause infertility are unknown. Despite high variability among cattle, number of follicles growing during the 2 or 3 follicular waves of estrous cycles is highly repeatable in individuals. Cattle with low vs high follicle numbers have traits of infertility, including high circulating concentrations of FSH, but a diminished: ovarian reserve, ovarian function, and response to superovulation. These observations provide rationale for the hypothesis that high vs low circulating FSH in cattle with low vs high follicle numbers causes infertility by diminishing function of dominant ovulatory follicles. Our approach to test this hypothesis is to determine whether secretion of LH and progesterone, responsiveness of ovulatory follicles to FSH and LH, and oocyte quality differ for cattle with low vs high follicle numbers. This approach is novel because it will determine if alterations in ovarian function are associated with the variation in size of the ovarian reserve in animals of similar ages. The results will provide insights into the mechanisms regulating infertility in healthy cattle and positively impact animal agriculture because discovery of a trait contributing to fertility, such as numbers of antral follicles per wave, that is highly repeatable within individuals and potentially highly heritable and correlated with fertility traits, would be very useful as a phenotypic marker to enhance reproductive efficiency in cattle.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
30134101030100%
Goals / Objectives
Specific Aims of this project are to determine whether the FSH and luteinizing hormone (LH) response systems in ovulatory follicles (Aim I), oocyte quality (Aim II), LH secretion (Aim III), and the LH response system in the corpus luteum (Aim IV) differ for cattle with low vs high follicle numbers during follicular waves.
Project Methods
Non lactating dairy cows (4 to 6 yrs old) with consistently low (no more than 15 antral follicles 3 mm or greater in diameter) or high (25 or more follicles) numbers of antral follicles growing during follicular waves will be identified by serial ovarian ultrasonography. A variety of assays will then be used to determine if number of gonadotropin receptors on granulosal/thecal cells, CREB and cAMP production, a variety of known gonadotropin target genes, gene markers and bioassays of oocyte quality, FSH or LH induced production of estradiol or progesterone by granulosal, thecal or luteal cells differ between the two groups of animals.

Progress 09/01/07 to 08/31/10

Outputs
OUTPUTS: OUTPUTS: Experiments were conducted to determine if secretion of gonadotropins, progesterone and anti-Mullerian homrone, differentiation and function of follicles, and oocyte quality differed between beef heifers with a consistently relatively low versus high number of antral follicles growing during follicular waves. Follicular differentiation and function and oocyte quality were evaluated by measuring a variety of gene, growth factor and(or) steroid markers previously shown to be potentially important for dominant follicle development and oocyte quality in the bovine. Experiments were also conducted to determine if secretion of progesterone and LH differed between young adult cattle with a low versus high number of antral follicles growing during follicular waves. Results were analyzed statistically and presented at a variety of national/international scientific meetings in 2007-11 as described below. Results were disseminated via oral and poster presentations at national and international meetings to the scientists, fellows and graduate students attending these meetings and interested in reproductive physiology of the bovine. In addition, the PD has communicated his findings to stakeholders in Michigan, California, Alaska, and in Ireland at local meetings and published in abstracts and refereed scientific journals results of these studies. PARTICIPANTS: The principal investigator of the project was James J. Ireland, Professor, Animal Science Department, Michigan State University. He was responsible for organization of all aspects of the study including publication of results. Dr. GW Smith, Professor, Animal Science at MSU provided advice/critique on all aspects of the project. Research assistants from the Department of Animal Science at MSU included: Dr. Joe Folger, who conducted mRNA analyses; Dr. Fermin Jimenez who conducted ovarian ultrasonography to identify cattle with low or high antral follicle count; Danielle Scheetz who conducted studies on anti-mullerian hormone; Janet Ireland who was responsible for all laboratory maintenance and safety and assisted in all laboratory aspects of the project. Collaborators included Dr. Alex Evans, Professor, Univ Coll Dublin, who organized all aspects of studies conducted in Dublin, Ireland including publications; Dr. Pat Lonergan, Professor, Univ Coll Dublin, who provided advice on oocyte recovery in cattle; and Dr. Francesca Mossa, who conducted studies on the impact of restriction of maternal diets during pregnancy on follicle numbers and health of female offspring. TARGET AUDIENCES: Results were disseminated orally and in posters at national and international meetings to scientists, fellows and graduate students attending these meetings and interested in reproductive physiology of the bovine. In addition, the PD has communicated his findings to stakeholders in Michigan, California, Alaska, and in Ireland at local meetings and published in abstracts and refereed scientific journals results of these studies. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Outcomes/Impacts:Results demonstrated for the first time that young adult cattle with relatively low versus a high antral follicle count during follicular waves had many phenotypic characteristics usually associated with ovarian aging, embryo mortality and infertility, including high concentrations of FSH and LH in serum during the estrous cycle, high abundance of cumulus cell markers for poor oocyte quality, but smaller ovaries and 80% lower number of high quality oocytes in ovaries, and 40 to 80% lower serum concentrations of progesterone and anti-Mullerian hormone throughout the estrous cycle. These novel results provided compelling rationale to determine if the inherently high variation in number of follicles growing during follicular waves impacts fertility in cattle. A positive outcome of this future study will provide the basis for new methods to select for high fertility cattle based on antral follicle counts during follicular waves as well as new methods to monitor the effect of nutrition, disease and drugs on fertility in female cattle.

Publications

  • Jimenez-Krassel F, Folger JK, Mondal M, Ireland JLH, Smith GW, Mossa F, Lonergan P, Evans ACO, Ireland JJ. 2009. Evidence that the inherently high variation in ovarian reserves is positively associated with androgen and estradiol production in cattle. Abstract presented to 42nd SSR Annual Meeting in Pittsburgh, PA, July 18-22.
  • Mossa F, Kenny D, Jimenez-Krassel F, Smith GW, Berry D, Butler S, Fair T, Lonergan P, Ireland JJ, Evans ACO. 2009. Effect of undernutrition of heifers during the first trimester of pregnancy on blood pressure in female offspring. Abstract presented at Gemini, Maternal Interaction with Gametes and Embryos, Workshop of Working group 1: Experimental models, Lansk, Poland, May 7-8.
  • Ireland JJ. 2009. The impact of variation in FSH secretion during follicular waves on dominant follicle function in cattle. CSREES-USDA NRI Animal Reproduction Investigator Meeting, Pittsburg, PA, July 22.
  • Mossa F, Butler ST, Berry DP, Lonergan P, Smith GW, Ireland JJ, Evans ACO. Number of follicles during follicular waves is positively associated with fertility in dairy cows. 2010. Abstract presented to the 8th International Ruminant Reproduction Symposium. Hilton Hotel, Anchorage, Alaska, Sept 3-7.
  • Ireland JJ, Scheetz D, Jimenez F, Folger JK, Smith GW, Mossa F, Evans ACO. 2010. Evidence that mammary gland infection/injury during pregnancy in dairy cows may have a negative impact on size of the ovarian reserve in their daughters. Abstract presented to the 43rd Annual Meeting for the Society for Study of Reproduction in Milwaukee, WI. July 30 - August 3.
  • Evans ACO, Mossa F, Fair T, Lonergan P, Smith GW, Jimenez-Krassel F, Folger JK, Ireland JLH, Ireland JJ. 2010. Variation in the number of ovarian follicles in cattle: possible causes and consequences. XXIV Annual Meeting of the SBTE (Sociedada Brasileira de Tecnologia de Embrioes), 19-21 August 2010, Porto de Galinhas, Brazil, Acta Scientiae Veterinariae 30 (Supl 2), s537-s543.
  • Ireland JJ. 2008. The impact of variation in FSH secretion during follicular waves on dominant follicle function in cattle. CSREES, USDA National Research Initiative Animal Reproduction Annual Investigator Meeting, Indianapolis, IN, July 10-11.
  • Mossa F, Kenny D, Jimenez-Krassel F, Smith GW, Berry D, Butler S, Fair T, Lonergan P, Ireland JJ, Evans ACO. 2009. Undernutrition of heifers during the first trimester of pregnancy diminishes size of the ovarian reserve in female offspring. Abstract presented to 42nd SSR Annual Meeting in Pittsburgh, PA, July 18-22.
  • Scheetz DM, Folger JK, Smith GW, Ireland JJ. 2009. Regulation of anti-Mullerian hormne (AMH) production by bovine granulosal cells. Abstract presented to 42nd SSR Annual Meeting in Pittsburgh, PA, July 18-22.
  • Ireland J.J., Ward F., Lonergan P., Jimenez-Krassel F., Ireland JLH, Smith G.W., Evans A.C.O. 2007. Follicle numbers are highly repeatable within animal but inversely correlated with FSH concentrations and the proportion of good quality embryos after superstimulation in cattle. Human Reproduction 22:1687-1695.
  • Zielak AE, Forde N, Park SDE, Doohan F, Coussens PM, Smith GW, Ireland JJ, Lonergan P, Evans ACO. 2007. Identification of novel genes associated with dominant follicle development in cattle. Reproduction, Fertility and Development 19(8):967-975.
  • Zielak AE, Canty MJ, Forde N, Coussens PM, Smith GW, Lonergan P, Ireland JJ, Evans ACO. 2008. Differential expression of genes for transcription factors in theca and granulosa cells following selection of a dominant follicle in cattle. Molecular Reproduction and Development 75(5):904-914.
  • Forde N, Mihm M, Canty M, Zielak A, Baker P, Park S, Lonergan P, Smith GW, Coussens PM, Ireland JJ, Evans AE. 2008. Differential expression of signal transduction factors during ovarian follicle development: a role for betaglycan and FIBP in granulosa cell function in cattle. Physiological Genomics 33(2):193-204.
  • JLH Ireland, Scheetz D, Jimenez-Krassel F, Themmen APN, Ward F, Lonergan P, Smith GW, Perez GI, Evans ACO, Ireland JJ. 2008. Antral follicle count reliably predicts number of morphologically healthy oocytes and follicles in ovaries of young adult cattle. Biol Reprod 79:1219-1225.
  • Ireland JJ, Zielak AE, Jimenez-Krassel F, Folger J, Bettegowda A, Scheetz D, Walsh S,Ward F, Knight PG, Smith GW, Lonergan P, Evans ACO. 2009. Variation in the ovarian reserve is linked to alterations in intrafollicular estradiol production and ovarian biomarkers of follicular differentiation and oocyte quality in cattle. Biol Reprod 80:954-964.
  • AE Zielak, F Ward, N Forde, F Mossa, P Lonergan, GW Smith, JJ Ireland, and ACO Evans. 2007. Comparison of ovarian follicles at follicle wave emergence between heifers with high versus low numbers of follicles. British Society of Animal Science. Abstract presented to: An International Conference Fertility in Dairy Cows bridging the gaps. Liverpool Hope University, UK, August 30-31.
  • Vanderlaan DJ, Khurshid K, Ireland JJ, Jimenez-Krassel F, McGough RJ. 2007. Automated follicle segmentation in ultrasound scans of bovine ovaries. The 13th International Symposium on Applied Electromagnetics and Mechanics (ISEM), Kellogg Conference Center, Michigan State University, Sept 9-12.
  • Ireland, J.J. 2007. Significance of number of antral follicle in ovarian follicular waves in cattle. Animal Reproduction Annual Investigator Meeting. CSREES-USDA, San Antonio, TX, July 21-25.
  • Mossa F, Jimenez-Krassel F, Butler S, Folger J, Smith GW, Lonergan P, Ireland JJ, Berry DP, Evans ACO. 2008. Alterations in FSH secretion and pituitary responsiveness to follicular fluid after ovariectomy of dairy cows with high versus low number of antral follicles. 16th International Congress on Animal Reproduction, Budapest, Hungary, July 13-17.
  • Jimenez-Krassel F, Folger JK, Ireland JLH, Smith GW, Hou X, Davis JS, Lonergan P, Evans ACO, Ireland JJ. 2009. Evidence that high variation in ovarian reserves of healthy young adults has a negative impact on the corpus luteum and endometrium during reproductive cycles of single-ovulating species. Biol Reprod 80: 1272-1281.
  • Vanderlaan DJ, Khurshid K, Ireland JJ, Jimenez-Krassel F, McGough RJ. 2008. Automated follicle segmentation in ultrasound scans of bovine ovaries. International Journal of Applied Electromagnetics and Mechanics 28:49-54.
  • Ireland JJ, Smith GW, Scheetz D, Jimenez-Krassel J, Folger JK, Ireland JLH, Mossa F, Lonergan P, Evans ACO. 2010. Does Size Matter in Females An overview of the impact of the high variation in the ovarian reserve on ovarian function and fertility, utility of AMH as a diagnostic marker for fertility, and causes of variation in the ovarian reserve in cattle. Reproduction, Fertility and Development. In Press.
  • Evans ACO, Mossa F, Fair T, Lonergan P, Berry DP, Butler ST, Zielak-Steciwko AE, Smith GW, Jimenez-Krassel F, Folger JK, Ireland JLH, Ireland JJ. 2010. Causes and consequences of the variation in the number of ovarian follicles in cattle. Reproduction in Domestic Ruminants VII. In Press.
  • Evans ACO, Mossa F, Fair T, Lonergan P, Smith GW, Jimenez-Krassel F, Folger JK, Ireland JLH, Ireland JJ. 2010. Variation in the number of ovarian follicles in cattle: possible causes and consequences. XXIV Annual Meeting of the SBTE (Sociedada Brasileira de Tecnologia de Embrioes), 19-21 August 2010, Porto de Galinhas, Brazil, Acta Scientiae Veterinariae 30 (Supl 2), s537-s543. In Press.
  • Ireland JLH, Jimenez-Krassel F, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2007. Variation in number of follicles growing during follicular waves reflects size of the ovarian reserve in cattle. Abstract submitted to 40th Annual Meeting for the Study of Reproduction, San Antonio, TX, July 21-25
  • Jimenez-Krassel F, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2007. Evidence that luteinization capacity of granulosal cells from dominant follicles is diminished in cattle with a depleted ovarian reserve. Abstract submitted to 40th Annual Meeting for the Study of Reproduction, San Antonio, TX, July 21-25
  • Mossa F, S.Butler, P.Duffy, F. Jimenez-Krassel, J Folger, G.W. Smith, P. Lonergan1, J.J. Ireland, A.C.O. Evans. 2007. Distribution of follicle numbers in dairy cows aged from 2 to 11 years. British Society of Animal Science. Abstract presented to: An International Conference Fertility in Dairy Cows bridging the gaps. Liverpool Hope University, UK, August 30-31.
  • Jimenez-Krassel F, Folger JK, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2008. Evidence that the diminished production of progesterone during estrous cycles of cattle with a low antral follicle count during follicular waves is repeatable and not caused by alterations in size of the corpus luteum. Abstract presented to Joint ADSA-ASAS Annual Meeting, Indianapolis, IN, July 7-11
  • Folger JK, Jimenez-Krassel F, Bettegowda A, Smith GW, Mossa F, Lonergan P, Evans ACO, Ireland. 2008. Evidence that numbers of mRNA transcripts for estrogen receptor alpha and beta are greater in cumulus cells and oocytes from cattle with a diminished ovarian reserve. Abstract presented at 41st SSR Annual Meeting in Kailua-Kona, Hawaii, May 27-30.
  • Scheetz D, Folger JK, Smith GW, Ireland JJ. 2010. Evidence that low antral follicle count during follicular waves negatively impacts FSH-induced capacity of bovine granulosal cells to produce estradiol and anti-Mullerian hormone (AMH). Abstract presented to the 43rd Annual Meeting for the Society for Study of Reproduction in Milwaukee WI,July 30 - August 3.
  • Evans ACO, Mossa F, Lonergan P, Butler S, Berry D, Ireland J. 2010. Causes and consequences of the variation in ovarian follicle numbers. Presented at the Reproductive Sciences and Medicine Research Symposium, University of Saskatchewan, Canada, March 26.
  • Evans ACO, Mossa F, Fair T, Lonergan P, Butler ST, Zielak-Steciwko AE, Smith GW, Jimenez-Krassel F, Folger JK, Ireland JLH, Ireland JJ. 2010. Causes and consequences of the variation in the number of ovarian follicles in cattle. Abstract 28. Presented at the 8th International Ruminant Reproduction Symposium, Hilton Hotel, Anchorage, AK, September 3-7.
  • Ireland JJ, Smith GW, Scheetz D, Jimenez-Krassel J, Folger JK, Ireland JLH, Mossa F, Lonergan P, Evans ACO. Does Size Matter in Females An overview of the impact of the high variation in the ovarian reserve on ovarian function and fertility, utility of AMH as a diagnostic marker for fertility, and causes of variation in the ovarian reserve in cattle. Proceedings of the annual conference of the IETS. Reproductive Biotechnology at the interface between animal agriculture and biomedical research. Orlando, FL, January 8-12, 2011.
  • Mossa F, Jimenez-Krassel F, Walsh S, Berry DP, Butler ST, Folger J, Smith GW, Ireland JLH, Lonergan P, Ireland JJ, Evans ACO. 2010. The inherent capacity of the pituitary gland to produce gonadotropins is not influenced by the number of ovarian follicles greater than 3 mm in diameter in cattle. Reproduction, Fertility and Development. 22:550-557.
  • Mossa F, Jimenez-Krassel, Folger JK, Ireland JLH, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2010. Evidence that high variation in antral follicle count during follicular waves is linked to alterations in androgen production in cattle. Reproduction. In Press. http://dx.doi.org/10.1530/REP-10-0214


Progress 09/01/08 to 08/31/09

Outputs
OUTPUTS: Differences in differentiation and function of follicles and the corpus luteum,and oocyte quality between beef and dairy cattle with consistently low versus a high antral follicle count during follicular waves were evaluated in a series of studies. This was accomplished by measuring patterns of secretion of gonadotropins, estradiol, progesterone, and anti-Mullerian hormone during estrous cycles and by measuring amounts of a variety of genes, hormones and growth factors previously shown to be potentially important for oocyte quality and for development and function of dominant follicles and the corpus luteum in cattle. All data were analyzed statistically and results were published in several refereed scientific journals and presented at a variety of national/international scientific meetings in 2008-09 as described below. Results were communicated via oral and poster presentations at national and international meetings to the scientists, fellows and graduate students attending these meetings and interested in reproductive physiology of the bovine. In addition, the PD has communicated his findings to stakeholders in Michigan and in Ireland at local meetings. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Results were published in several refereed scientific journals and presented at a variety of national/international scientific meetings in 2008-09 as described below. Results were communicated via oral and poster presentations at national and international meetings to the scientists, fellows and graduate students attending these meetings and interested in reproductive physiology of the bovine. In addition, the PD has communicated his findings to stakeholders in Michigan and in Ireland at local meetings. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results demonstrated for the first time that young adult cattle with relatively low versus a high antral follicle count during follicular waves had many phenotypic characteristics usually associated with ovarian aging, embryo mortality and infertility, including high concentrations of FSH and LH in serum during the estrous cycle, high abundance of cumulus cell markers for poor oocyte quality, but smaller ovaries and 80% lower number of high quality oocytes in ovaries, and 40 to 80% lower serum concentrations of progesterone and anti-Mullerian hormone throughout the estrous cycle. These novel results provided compelling rationale to determine if the inherently high variation in number of follicles growing during follicular waves impacts fertility in cattle. A positive outcome of this future study will provide the basis for new methods to select for high fertility cattle based on antral follicle counts during follicular waves as well as new methods to monitor the effect of nutrition, disease and drugs on fertility in female cattle.

Publications

  • JLH Ireland, Scheetz D, Jimenez-Krassel F, Themmen APN, Ward F, Lonergan P, Smith GW, Perez GI, Evans ACO, Ireland JJ. 2008. Antral follicle count reliably predicts number of morphologically healthy oocytes and follicles in ovaries of young adult cattle. Biol Reprod 79:1219-1225.
  • Ireland JJ. 2009. The impact of variation in FSH secretion during follicular waves on dominant follicle function in cattle. CSREES-USDA NRI Animal Reproduction Investigator Meeting, Pittsburg, PA, July 22.
  • Ireland JJ, Zielak AE, Jimenez-Krassel F, Folger J, Bettegowda A, Scheetz D, Walsh S,Ward F, Knight PG, Smith GW, Lonergan P, Evans ACO. 2009. Variation in the ovarian reserve is linked to alterations in intrafollicular estradiol production and ovarian biomarkers of follicular differentiation and oocyte quality in cattle. Biol Reprod 80:954-964.
  • Ireland JJ. 2008. The impact of variation in FSH secretion during follicular waves on dominant follicle function in cattle. CSREES, USDA National Research Initiative Animal Reproduction Annual Investigator Meeting, Indianapolis, IN, July 10-11.
  • Scheetz DM, Folger JK, Smith GW, Ireland JJ. 2009. Regulation of anti-Mullerian hormne (AMH) production by bovine granulosal cells. Abstract presented to 42nd SSR Annual Meeting in Pittsburgh, PA, July 18-22.
  • Jimenez-Krassel F, Folger JK, Mondal M, Ireland JLH, Smith GW, Mossa F, Lonergan P, Evans ACO, Ireland JJ. 2009. Evidence that the inherently high variation in ovarian reserves is positively associated with androgen and estradiol production in cattle. Abstract presented to 42nd SSR Annual Meeting in Pittsburgh, PA, July 18-22.


Progress 09/01/07 to 08/31/08

Outputs
OUTPUTS: Experiments were conducted to determine if differentiation and function of follicles and oocyte quality differed between beef heifers with a consistently relatively low versus high number of antral follicles growing during follicular waves. Follicular differentiation and function and oocyte quality were evaluated by measuring a variety of gene, growth factor and(or) steroid markers previously shown to be potentially important for dominant follicle development and oocyte quality in the bovine. Experiments were also conducted to determine if secretion of progesterone and LH differed between young adult cattle with a low versus high number of antral follicles growing during follicular waves. Results were presented at a variety of national/international scientific meetings in 2007-08 as described below. PARTICIPANTS: James J. Ireland: PD, organized all aspects of research. TARGET AUDIENCES: Results of our studies were communicated via oral and poster presentations at national and international meetings to the scientists, fellows and graduate students attending these meetings and interested in reproductive physiology of the bovine. In addition, the PD has communicated his findings to stakeholders in Michigan and in Ireland at local meetings. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results of these studies demonstrate for the first time that young adult cattle with relatively low versus high follicle numbers during follicular waves have much higher intrafollicular concentrations of estradiol (high estradiol causes impaired oocyte maturation in vitro), greater abundance of mRNA for ER beta receptor in oocytes, greater abundance of aromatase mRNA in granulosal cells and ER beta and alpha receptors in cumulus cells, lower basal LH concentrations during estrous cycles, higher abundance of mRNA for cathepsin in cumulus cells (marker for poor egg quality), and higher amplitude of episodic LH secretion (on Day 11 of cycle) but much lower circulating progesterone concentrations during estrous cycles. Several studies in the bovine report that high estradiol concentrations during in vitro maturation of oocytes, high mRNA abundance of cathepsin in cumulus cells and low circulating progesterone concentrations during estrous cycles are associated with impaired oocyte maturation, poor oocyte quality and compromised embryo development, respectively. These results, coupled with the aforementioned results using the low versus high bovine model, provide strong rationale to determine if the variation in number of follicles growing during follicular waves impacts fertility in cattle. A positive outcome of this future study will provide the basis for new methods to select for high fertility cattle based on antral follicle counts during folliuclar waves.

Publications

  • Ireland JLH, Jimenez-Krassel F, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2007. Variation in number of follicles growing during follicular waves reflects size of the ovarian reserve in cattle. Abstract submitted to 40th Annual Meeting for the Study of Reproduction, San Antonio, TX, July 21-25 Jimenez-Krassel F, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2007. Evidence that luteinization capacity of granulosal cells from dominant follicles is diminished in cattle with a depleted ovarian reserve. Abstract submitted to 40th Annual Meeting for the Study of Reproduction, San Antonio, TX, July 21-25
  • Mossa F, Butler S, Duffy P, Jimenez-Krassel F, Folger J, Smith GW, Lonergan P, Ireland JJ, Evans ACO. 2007. Distribution of follicle numbers in dairy cows aged from 2 to 11 years. British Society of Animal Science. Abstract presented to: An International Conference Fertility in Dairy Cows bridging the gaps. Liverpool Hope University, UK, August 30-31.
  • Zielak AE, Ward F, Forde N, Mossa F, Lonergan P, Smith GW, Ireland JJ, and Evans ACO. 2007. Comparison of ovarian follicles at follicle wave emergence between heifers with high versus low numbers of follicles. British Society of Animal Science. Abstract presented to: An International Conference Fertility in Dairy Cows bridging the gaps. Liverpool Hope University, UK, August 30-31.
  • Vanderlaan DJ, Khurshid K, Ireland JJ, Jimenez-Krassel F, McGough RJ. 2007. Automated follicle segmentation in ultrasound scans of bovine ovaries. The 13th International Symposium on Applied Electromagnetics and Mechanics (ISEM), Kellogg Conference Center, Michigan State University, Sept 9-12.
  • Ireland, J.J. 2007. Significance of number of antral follicle in ovarian follicular waves in cattle. Animal Reproduction Annual Investigator Meeting. CSREES-USDA, San Antonio, TX, July 21-25.
  • Mossa F, Jimenez-Krassel F, Butler S, Folger J, Smith GW, Lonergan P, Ireland JJ, Berry DP, Evans ACO. 2008. Alterations in FSH secretion and pituitary responsiveness to follicular fluid after ovariectomy of dairy cows with high versus low number of antral follicles. 16th International Congress on Animal Reproduction, Budapest, Hungary, July 13-17.
  • Jimenez-Krassel F, Folger JK, Smith GW, Lonergan P, Evans ACO, Ireland JJ. 2008. Evidence that the diminished production of progesterone during estrous cycles of cattle with a low antral follicle count during follicular waves is repeatable and not caused by alterations in size of the corpus luteum. Abstract presented to Joint ADSA-ASAS Annual Meeting, Indianapolis, IN, July 7-11
  • Folger JK, Jimenez-Krassel F, Bettegowda A, Smith GW, Mossa F, Lonergan P, Evans ACO, Ireland. 2008. Evidence that numbers of mRNA transcripts for estrogen receptor alpha and beta are greater in cumulus cells and oocytes from cattle with a diminished ovarian reserve. Abstract presented at 41st SSR Annual Meeting in Kailua-Kona, Hawaii, May 27-30.