SAES-422 Multistate Research Activity Accomplishments Report
Sections
Status: Approved
Basic Information
- Project No. and Title: NC1006 : Methods to Increase Reproductive Efficiency in Cattle (Rev. NC-113)
- Period Covered: 10/01/2000 to 09/01/2001
- Date of Report: 09/12/2002
- Annual Meeting Dates: 10/25/2001 to 10/26/2001
Participants
Hamernik, D., dhamernik@intranet.reeusda.gov, US Dept. of Agriculture, Washington DC; Ravlin, F.W., ravlin.1@osu.edu, Ohio State University, Wooster, OH; Anderson, L.L., llanders@iastate.edu, Iowa State University, Ames, IA; Garverick, H.A., GarverickA@missouri.edu, University of Missouri, Colombia, MO; Kesler, D.J., d-kesler@ux6.cso.uiuc.edu, University of Illinois, Urbana, IL; Krisher, R.L., rkrisher@purdue.edu, Purdue University, West Lafayette, IN; Lamb, G.C., clamb@umn.edu, University of Minnesota, Grand Rapids, MN; Ottobre, J.S., ottobre.2@osu.edu, Ohio State University, Columbus, OH; Pursley, J.R., pursleyr@pilot.msu.edu, Michigan State University, East Lansing, MI; Stevenson, J.S., jstevens@oz.oznet.ksu.edu, Kansas State University, Manhattan, KS; Wiltbank, M.C., wiltbank@calshp.cals.wisc.edu, University of Wisconsin, Madison, WI
Accomplishments
NC-113 Joint Project 1: Improved fertility in anovulatory lactating dairy cows treated with exogenous progesterone during Ovsynch (MI, WI, MO, IL, OH, KS).
The NC-113 technical committee is in the fourth year of their 5-year project, and has spent the last 12 months completing the objectives of that project. In addition, the committee has recently submitted a proposal for an additional 5-year project. Pending the acceptance of that project, our plans are continue collaborative multi-station research to target the identification and treatment of anovulatory lactating dairy cows and test the efficacy of the CIDR in enhancing pregnancy rates to a synchronized breeding and synchronizing the return estrus for non-pregnant suckled beef cows. Basic studies investigating regulation of these functions also will be conducted.
Our objective was to determine whether providing supplemental progesterone (P4) before induced luteolysis would enhance fertility in lactating dairy cows. Supplemental P4 was tested in the form of an intravaginal progesterone insert (CIDR) administered at the first injection of GnRH of the Ovsynch protocol. Recall that the Ovsynch protocol begins with an injection of GnRH to synchronize the onset of follicular development. In this experiment, the CIDR was inserted at this time in half of the cows. Seven days later, the CIDR was removed, and an injection of PGF was given 2 hr later to induce luteal regression. Another injection of GnRH was given 48 hr after PGF. This injection helps to synchronize timing of ovulation. The second GnRH injection was followed in 12 to 18 hr by timed AI (TAI).
Lactating dairy cows (n=634) from six Midwest herds were assigned randomly within parity and stage of lactation to receive Ovsynch or Ovsynch + CIDR at a random stage of an estrous cycle. Blood was sampled to quantify P4 10 days before first GnRH, at first GnRH, at removal of CIDR, at PGF, and 48 hr post-PGF to determine cycling status at time of first GnRH, status at time of PGF (high or low P4), and CL regression. Synchronization rate was defined as the percentage of cows with: 1) serum P4 <1 ng/ml 48 hr after PGF and 2) a follicle >9 mm that disappeared within 48 hr after the second GnRH. Size of ovulatory follicle at time of second GnRH and its disappearance 48 hr later, and pregnancy diagnosis at 28 and 56 days following TAI, were determined by ultrasound.
A location W treatment interaction (P=0.019) occurred for pregnancy rates. Pregnancy rates per TAI (%), percentage cycling, and average days in milk (DIM) are illustrated in the table below for each location. Noncycling cows (n=182) that received Ovsynch + CIDR had greater (P<0.05) pregnancy rates (55.2%) than noncycling cows that received Ovsynch (34.7%) on day 28 after TAI. Pregnancy loss between 28 and 56 days after TAI was not different between Ovsynch and Ovsynch + CIDR regardless of cycling status. Synchronization rate was similar after the Ovsynch (83.1%) and Ovsynch + CIDR (82.3%) protocols. In summary, a CIDR inserted during the Ovsynch protocol enhanced fertility in non-cycling cows.
NC113 Joint Project 2: Inclusion of an intravaginal progesterone insert plus GnRH and prostaglandin F2α for ovulation control in postpartum suckled beef cows (MN, KS, IL, MO).
Four experiment stations conducted experiments to determine effects of introducing a CIDR insert into an ovulation control program for postpartum suckled beef cows. Cows (n=560) were assigned randomly to two treatments: 1) 100 g of GnRH (i.m.) followed in 7 days with 25 mg of PGF2α, followed in 48 hr by a second injection of GnRH and one fixed-time insemination (Cosynch; n = 287) or 2) Cosynch plus one CIDR during the 7 days between the first injection of GnRH and PGF2 (Cosynch+P; n = 273). Cows at three stations were inseminated at the time of the second GnRH injection (n = 462), whereas 98 cows at the fourth station were inseminated 16 to 18 hr after that injection. Blood samples were collected at days 17, 7, 0, and 2 relative to PG F2 to determine concentrations of progesterone. Ultrasonography was used to monitor follicle diameter on day 2 and to determine the presence of an embryo at 30 to 35 days after insemination.
Pregnancy rates were greater (P < 0.05) for Cosynch+P (58%) than for Cosynch-treated (48%) cows. No station W treatment interaction occurred; however, cows at MO (62%) and KS (60%) had greater (P < 0.05) pregnancy rates than those at IL (47%) and MN (44%). Cows that had follicles >12 mm on day 2 had greater (P < 0.01) pregnancy rates than those with follicles less than or equal to 12 mm regardless of treatment. Pregnancy rates were similar between Cosynch and Cosynch+P treatments when cycling cows had elevated concentrations of progesterone at day 0, but pregnancy rates were greater (P < 0.05) in the Cosynch+P (79%) than in the Cosynch (43%) treatment when cycling cows had low concentrations of progesterone on day 0 (at PGF2 injection). Similarly, among noncycling cows, pregnancy rates were greater (P < 0.05) in the Cosynch+P (59%) treatment than in the Cosynch (39%) treatment. Cows in greater body condition at the onset of the breeding season experienced improved (P < 0.001) overall pregnancy rates. Pregnancy rates for cows that calved >50 days before the onset of the breeding season were greater (P < 0.01) than those for cows that calved <50 days. Thus, treatment of suckled cows with Cosynch yielded acceptable pregnancy rates, but addition of a CIDR improved pregnancy rates in noncycling cows. Body condition and days postpartum at initiation of the breeding season affected overall efficacy of the Cosynch and Cosynch+P protocols.
To achieve optimal pregnancy rates with either the Cosynch or Cosynch plus progesterone protocols, cows should be in good body condition (body condition score >5) and treatments should be initiated only when cows are at least 50 days postpartum. Adding a progesterone insert at the time of the GnRH injection improves fertility, especially in cows not cycling at the onset of the breeding season. Further refinement and success of these treatments should increase the convenience and appeal of applying artificial insemination to suckled beef cows.
During the past 5 years, our group has conducted and completed two cooperative experiments. The first experiment involved testing the efficacy of adding progesterone (via a progesterone-releasing intravaginal insert; CIDR-B; InterAg, Hamilton, NZ) to the Ovsynch protocol in lactating dairy cows. This experiment was replicated at seven (IL, KS, IN, OH, MI, MO, and WI) of the nine experiment stations involved in NC-113 (Pursley et al., 2001). Addition of the CIDR to the Ovsynch protocol increased pregnancy rates in cows that had not resumed estrous cycles before the onset of the protocol from 34.7% (n = 95) with the Ovsynch protocol alone to 55.2% (n = 87) with the protocol plus addition of the CIDR. Overall, pregnancy rates increased from 40.9% (n = 320) to 50.8% (n = 313), respectively. In addition, we have reported that pregnancy rates after the Ovsynch protocol are improved further when the protocol is applied to cows in their early luteal phase (Vasconcelos et al., 1999) or when estrous cycles of cows are presynchronized with one (Cartmill et al., 2001) or two (El-Zarkouny et al., 2001) injections of PGF2 administered 14 days apart, with the second or only injection given 12 days before the onset of the Ovsynch protocol. In a second experiment a similar protocol in suckled beef cows was tested where the Cosynch protocol was compared to the Cosynch protocol + supplemental progesterone provided by the CIDR (Lamb et al., 2001). This experiment was replicated at four (IL, KS, MN, and MO) of the seven stations. We found that pregnancy rates were increased from 48% (n = 188) with Cosynch protocol alone to 58% (n = 177) with the same protocol plus the CIDR. Both of these protocols were carried out without any estrus detection and all cows were inseminated at one fixed time.
The NC-113 technical committee is in the fourth year of their 5-year project, and has spent the last 12 months completing the objectives of that project. In addition, the committee has recently submitted a proposal for an additional 5-year project. Pending the acceptance of that project, our plans are continue collaborative multi-station research to target the identification and treatment of anovulatory lactating dairy cows and test the efficacy of the CIDR in enhancing pregnancy rates to a synchronized breeding and synchronizing the return estrus for non-pregnant suckled beef cows. Basic studies investigating regulation of these functions also will be conducted.
Our objective was to determine whether providing supplemental progesterone (P4) before induced luteolysis would enhance fertility in lactating dairy cows. Supplemental P4 was tested in the form of an intravaginal progesterone insert (CIDR) administered at the first injection of GnRH of the Ovsynch protocol. Recall that the Ovsynch protocol begins with an injection of GnRH to synchronize the onset of follicular development. In this experiment, the CIDR was inserted at this time in half of the cows. Seven days later, the CIDR was removed, and an injection of PGF was given 2 hr later to induce luteal regression. Another injection of GnRH was given 48 hr after PGF. This injection helps to synchronize timing of ovulation. The second GnRH injection was followed in 12 to 18 hr by timed AI (TAI).
Lactating dairy cows (n=634) from six Midwest herds were assigned randomly within parity and stage of lactation to receive Ovsynch or Ovsynch + CIDR at a random stage of an estrous cycle. Blood was sampled to quantify P4 10 days before first GnRH, at first GnRH, at removal of CIDR, at PGF, and 48 hr post-PGF to determine cycling status at time of first GnRH, status at time of PGF (high or low P4), and CL regression. Synchronization rate was defined as the percentage of cows with: 1) serum P4 <1 ng/ml 48 hr after PGF and 2) a follicle >9 mm that disappeared within 48 hr after the second GnRH. Size of ovulatory follicle at time of second GnRH and its disappearance 48 hr later, and pregnancy diagnosis at 28 and 56 days following TAI, were determined by ultrasound.
A location W treatment interaction (P=0.019) occurred for pregnancy rates. Pregnancy rates per TAI (%), percentage cycling, and average days in milk (DIM) are illustrated in the table below for each location. Noncycling cows (n=182) that received Ovsynch + CIDR had greater (P<0.05) pregnancy rates (55.2%) than noncycling cows that received Ovsynch (34.7%) on day 28 after TAI. Pregnancy loss between 28 and 56 days after TAI was not different between Ovsynch and Ovsynch + CIDR regardless of cycling status. Synchronization rate was similar after the Ovsynch (83.1%) and Ovsynch + CIDR (82.3%) protocols. In summary, a CIDR inserted during the Ovsynch protocol enhanced fertility in non-cycling cows.
NC113 Joint Project 2: Inclusion of an intravaginal progesterone insert plus GnRH and prostaglandin F2α for ovulation control in postpartum suckled beef cows (MN, KS, IL, MO).
Four experiment stations conducted experiments to determine effects of introducing a CIDR insert into an ovulation control program for postpartum suckled beef cows. Cows (n=560) were assigned randomly to two treatments: 1) 100 g of GnRH (i.m.) followed in 7 days with 25 mg of PGF2α, followed in 48 hr by a second injection of GnRH and one fixed-time insemination (Cosynch; n = 287) or 2) Cosynch plus one CIDR during the 7 days between the first injection of GnRH and PGF2 (Cosynch+P; n = 273). Cows at three stations were inseminated at the time of the second GnRH injection (n = 462), whereas 98 cows at the fourth station were inseminated 16 to 18 hr after that injection. Blood samples were collected at days 17, 7, 0, and 2 relative to PG F2 to determine concentrations of progesterone. Ultrasonography was used to monitor follicle diameter on day 2 and to determine the presence of an embryo at 30 to 35 days after insemination.
Pregnancy rates were greater (P < 0.05) for Cosynch+P (58%) than for Cosynch-treated (48%) cows. No station W treatment interaction occurred; however, cows at MO (62%) and KS (60%) had greater (P < 0.05) pregnancy rates than those at IL (47%) and MN (44%). Cows that had follicles >12 mm on day 2 had greater (P < 0.01) pregnancy rates than those with follicles less than or equal to 12 mm regardless of treatment. Pregnancy rates were similar between Cosynch and Cosynch+P treatments when cycling cows had elevated concentrations of progesterone at day 0, but pregnancy rates were greater (P < 0.05) in the Cosynch+P (79%) than in the Cosynch (43%) treatment when cycling cows had low concentrations of progesterone on day 0 (at PGF2 injection). Similarly, among noncycling cows, pregnancy rates were greater (P < 0.05) in the Cosynch+P (59%) treatment than in the Cosynch (39%) treatment. Cows in greater body condition at the onset of the breeding season experienced improved (P < 0.001) overall pregnancy rates. Pregnancy rates for cows that calved >50 days before the onset of the breeding season were greater (P < 0.01) than those for cows that calved <50 days. Thus, treatment of suckled cows with Cosynch yielded acceptable pregnancy rates, but addition of a CIDR improved pregnancy rates in noncycling cows. Body condition and days postpartum at initiation of the breeding season affected overall efficacy of the Cosynch and Cosynch+P protocols.
To achieve optimal pregnancy rates with either the Cosynch or Cosynch plus progesterone protocols, cows should be in good body condition (body condition score >5) and treatments should be initiated only when cows are at least 50 days postpartum. Adding a progesterone insert at the time of the GnRH injection improves fertility, especially in cows not cycling at the onset of the breeding season. Further refinement and success of these treatments should increase the convenience and appeal of applying artificial insemination to suckled beef cows.
During the past 5 years, our group has conducted and completed two cooperative experiments. The first experiment involved testing the efficacy of adding progesterone (via a progesterone-releasing intravaginal insert; CIDR-B; InterAg, Hamilton, NZ) to the Ovsynch protocol in lactating dairy cows. This experiment was replicated at seven (IL, KS, IN, OH, MI, MO, and WI) of the nine experiment stations involved in NC-113 (Pursley et al., 2001). Addition of the CIDR to the Ovsynch protocol increased pregnancy rates in cows that had not resumed estrous cycles before the onset of the protocol from 34.7% (n = 95) with the Ovsynch protocol alone to 55.2% (n = 87) with the protocol plus addition of the CIDR. Overall, pregnancy rates increased from 40.9% (n = 320) to 50.8% (n = 313), respectively. In addition, we have reported that pregnancy rates after the Ovsynch protocol are improved further when the protocol is applied to cows in their early luteal phase (Vasconcelos et al., 1999) or when estrous cycles of cows are presynchronized with one (Cartmill et al., 2001) or two (El-Zarkouny et al., 2001) injections of PGF2 administered 14 days apart, with the second or only injection given 12 days before the onset of the Ovsynch protocol. In a second experiment a similar protocol in suckled beef cows was tested where the Cosynch protocol was compared to the Cosynch protocol + supplemental progesterone provided by the CIDR (Lamb et al., 2001). This experiment was replicated at four (IL, KS, MN, and MO) of the seven stations. We found that pregnancy rates were increased from 48% (n = 188) with Cosynch protocol alone to 58% (n = 177) with the same protocol plus the CIDR. Both of these protocols were carried out without any estrus detection and all cows were inseminated at one fixed time.
Impacts
Publications
HARD, D. L., R. K. BHATNAGAR, J. R. MOLINA and L. L. ANDERSON. 2001. Secretion of dopamine and norepinephrine in hypophyseal portal blood and prolactin in peripheral blood of Holstein cattle. DOMESTIC ANIMAL ENDOCRINOLOGY 20:89-100.
WILLIAMS, G. L., O. S. GAZAL, L. S. LESHIN, R. L. STANKO, and L. L. ANDERSON. 2001. Physiological regulation of maternal behavior in heifers: roles of genital stimulation, intracerebral oxytocin release, and ovarian steroids. BIOLOGY OF REPRODUCTION 65:295-300.
KIM, K.-S., J.M. REECY, L.L. ANDERSON and M.F. ROTHSCHILD. 2001. Functional characterization of the missense variation in the porcine melanocortin-4 receptor gene associated with obesity-related traits in the pig. PROCEEDINGS OF THE PLANT & ANIMAL GENOME IX, Page 210. (San Diego)
CHO, S.-J., K. JEFTINIJA, A. GLAVASKI, S. JEFTINIJA, B.P. JENA and L.L. ANDERSON. 2001. Fusion pores in GH-secreting cells. 31st Annual Meeting of the SOCIETY FOR NEUROSCIENCE, Nov. 10-15, 2001. PROCEEDINGS OF SOCIETY FOR NEUROSCIENCE 27:Abstract (San Diego)
CAAMAQO, J. N., S. OOKUTSU, M. L. PUGH, L. L. TIMMS, L. L. ANDERSON, P. M. DIXON and C. R. YOUNGS. 2001. Effect of FSH treatment on the developmental competence of oocytes recovered from postpartum dairy cows. 27th Annual Conference of the INTERNATIONAL EMBRYO TRANSFER SOCIETY (IETS), Jan. 14-16, 2001. Abstract (Omaha)
WILSON, M.E., K.A. VONNAHME and S.P. FORD. 2001. Role of altered uterine-embryo synchrony on conceptus growth in the pig. J. Anim. Sci. (In Press).
VONNAHME, K.A., M.E. WILSON and S.P. FORD. 2001. Relationship between placental vascular endothelial growth factor expression and placental/endometrial vascularity in the pig. Biol. Reprod. 64:1821-1825.
YOUNGS, C.R. 2001. Factors influencing the success of embryo transfer in the pig. THERIOGENOLOGY 56:1311-1320.
SIEREN, K.R. 2001. The Use of BoviPure for the separation of X and Y chromosome-bearing bovine sperm cells. M.S. Thesis, Iowa State Univ., 61 pp.
YOUNGS, C.R. 2001. Cattle breeding in the 21st century. Proc. Of the 30th Annual Cornbelt Cow-Calf Conference, Feb. 24, Ottumwa, IA, pp. 1-9.
DIKEMAN, M.A., D.R. STROHBEHN, and C.R. YOUNGS. 2001. Development of a web-based scheduling program for synchronization of estrus in cattle. JOURNAL OF ANIMAL SCIENCE 79(Suppl. 2):15 (abstr.)
FUNK, D.J. and C.R. YOUNGS. 2001. Embryo transfer, in vitro fertilization, cloning and transgenic production in farm animals: A review. Proc. Of the Student American Veterinary Medical Association Symposium, March 8-10, Ames, IA, p. 89 (abstr.)
PUGH, M.L., K.R. SIEREN, L.L. TIMMS, and C.R. YOUNGS. 2001. Use of a vaginal mucus electrical resistance probe to alter insemination time and calf gender distribution in dairy heifers. JOURNAL OF DAIRY SCIENCE 84(Suppl. 1):64 (abstr.).
Cartmill, J.A., S.Z. El-Zarkouny, B.A. Hensley, G.C. Lamb, and J.S. Stevenson. 2001. Stage of cycle, incidence and timing of ovulation , and pregnancy rates in dairy cattle after three timed breeding protocols. J. Dairy Sci. 84:84:1051-1059.
Lamb, G.C., J. S. Stevenson, D. J. Kesler, H.A. Garverick, D.R. Brown, and B. E. Salfen. 2001. Inclusion of an intravaginal progesterone insert plus GnRH and prostaglandin F2 for ovulation control in postpartum suckled beef cows. J. Anim. Sci. In press.
Medina-Britos, M.A., A.M. Richardson, G.C. Lamb, C.R. Dahlen, S.K. Johnson, S.Z. El-Zarkouny, B.A. Hensley, and J.S. Stevenson. 2001. Ovulation synchronization using progestins, GnRH, and PGF2 before timed AI (TAI) and resetting follicular waves for resynchronization of repeat inseminations of suckled beef cattle. J. Anim. Sci. 79(Suppl. 1):249-250 (Abstr. #1031).
Richardson, A.M., B.A. Hensley, and J.S. Stevenson. 2001. Characteristics of estrus before and after insemination and fertility after estrus synchronization with GnRH , PGF2, and progesterone in dairy heifers. J. Dairy Sci. 84:(Suppl. 1):249 (Abstr. #1029).
Stevenson, J.S. 2001. Incidence of anestrous in suckled beef cows and milked dairy cattle. J. Anim. Sci. 79(Suppl. 1):116 (Abstr. #481).
Johnson, S.K., J.S. Stevenson, K.R. Harmoney, and J.R. Brethour. 2001. Effects of pre and/or postpartum fat supplementation on reproduction in mature beef cows. J. Anim. Sci. 79(Suppl. 1):275 (Abstr. #1136).
El-Zarkouny, S.Z., J.A. Cartmill, A.M. Richardson, M.A. Medina-Britos, B.A. Hensley, and J.S. Stevenson. 2001. Presynchronization of estrous cycles in lactating dairy cows with Ovsynch + CIDR and resynchronization of repeat estrus using the CIDR. J. Dairy Sci. 84:(Suppl. 1):249 (Abstr. #1028).
Pursley, J.P., P.M. Fricke, H.A. Garverick, D.J. Kesler, J.S. Ottobre, J.S. Stevenson, and M.C. Wiltbank. 2001. Improved fertility in noncycling lactating dairy cows treated with progesterone during Ovsynch. Midwest ADSA/ASAS Mtg., Des Moines, IA, March19-21 (Abstr. #251).
Cartmill, J. A., S. Z. El-Zarkouny, B.A. Hensley, G.C. Lamb, and J.S. Stevenson. 2001. Stage of cycle, incidence and timing of ovulation , and pregnancy rates in dairy cattle after three timed breeding protocols. J. Dairy Sci. 84:1051-1059.
Dahlen, C.R., G.C. Lamb, B. Lindsay, A. DiCostanzo, D.R. Brown, A.R. Spell, and L.R. Miller. 2001. Pregnancy rates in recipients after receiving either two-identical demi-embryos or a single whole embryo. Theriogenology (In Press).
Medina-Britos, M.A., A.M. Richardson, G.C. Lamb, C.R. Dahlen, S.K. Johnson, S.Z. El-Zarkouny, B.A. Hensley, and J.S. Stevenson. Ovulation synchronization using progestins, GnRH, and PGF2 before timed AI (TAI) and resetting follicular waves for resynchronization of repeat inseminations of suckled beef cattle. J. Anim. Sci. 79(Suppl. 1):249.
Spell, A.R., W.R. Beal, L.R. Corah, and G.C. Lamb. 2001. Evaluating recipient and embryo factors that affect pregnancy rates of embryo transfer in beef cattle. Theriogenology 56:287-298.
Laughlin, M.H., W.G. Schrage, R.M. McAllister, H.A. Garverick and A.W. Jones. 2001. Interaction of gender and exercise training: vasomotor reactivity of porcine skeletal muscle arteries. J. Applied Physiology 90:216-227.
Calder, M.D., M. Manikkam, B.E. Salfen, R.S. Youngquist, D.B. Lubahn, W.R. Lamberson and H.A. Garverick. 2001. Dominant voine ovarian follicular cysts express increased levels of messenger RNAs for luteinizing-hormone receptor and 3-hydroxysteroid dehydrogenase 4, 5 isomerase compared to normal dominant follicles. Biol. Reprod. 65:471-476.
Salfen, B.E., F.N. Kojima, J.F. Bader, M.F. Smith and H.A. Garverick. 2001. Effect of short-term calf removal at three stages of a follicular wave on fate of a dominant follicle in postpartum beef cows. J. Anim. Sci. (in press).
M. Manikkam, M.D. Calder, B.E. Salfen, R.S. Youngquist, D.H. Keisler, and H.A. Garverick. 2001. Concentrations of steroids and gene expression of steroidogenic enzymes and gonadotropin receptors in bovine ovarian follicles of first and second waves and changes in second wave follicles after pulsatile LH infusion. Anim. Reprod. Sci. 67:189-203.
Hampton, J.H., M. Manikkam, D.B. Lubahn, M.F. Smith and H.A. Garverick. 2001. Androgen receptor mRNA expression inbovine ovarian follicles. Annual Mt Society of Study Reprod., Ottowa, Canada. July.
Pursley, J.R., P.M. Fricke, H.A. Garverick, D.J. Kesler, J.S. Ottober, J.S. Stevenson and M.C. Wiltbank. 2001. Improved fertility in noncycling lactating dairy cows treated with exogenous progesterone during ovsynch. NC-113 Regional Research Project. American Society of Animal Science and American Dairy Science Assoc. Midwest Section Annual Mtg, March.
Ching, S., D.C. Mahan, J.S. Ottobre, and K. Dabrowski. 2001. Ascorbic acid synthesis in fetal and neonatal pigs and in pregnant and postpartum sows. J. Nutrition 131:1997-2001.
Glogowski, J., J. Jankowski, A. Faruga, J.S. Ottobre, and A. Ciereszko. 2001. Acrosin activity in turkey spermatozoa: assay by clinical method and effect of zinc and benzamidine on the activity. Theriogenology 56:889-901.
Sartori R, Fricke P, Ferreira JCP, Ginther OJ, Wiltbank MC, 2001. Follicular deviation and acquisition of ovulatory capacity in bovine follicles. Biology of Reproduction 65:1403-1409.
Cordoba MC, Sartori R, Fricke PM, 2001. Assessment of a commercially available Early Conception Factor (ECF) test for determining pregnancy status of dairy cattle. Journal of Dairy Science 84:1884-1889.
Tsai SJ, Wiltbank MC, 2001 Differential effects of prostaglandin F-2 alpha on in vitro luteinized bovine granulosa cells. Biology of Reproduction. 122:245-253.
Vasconcelos JLM, Sartori R, Oliveira HN, Guenther JG, Wiltbank MC, 2001. Reduction in size of the ovulatory follicle reduces subsequent luteal size and pregnancy rate. Theriogenology. 56:307-314.
Beg MA, Bergfelt DR, Kot K, Wiltbank MC, Ginther OJ, 2001. Follicular-fluid factors and granulosa-cell gene expression associated with follicle deviation in cattle. Biology of Reproduction 64:432-441.
Wu Z, Kanneganti VR, Massingill LJ, Wiltbank MC, Walgenbach RP, Satter LD, 2001. Milk production of fall-calving dairy cows during summer grazing of grass or grass-clover pasture. Journal of Dairy Science. 84:1166-1173.
Olson KK, Anderson LE, Wiltbank MC, Townson DH, 2001. Action of prostaglandin F2a and prolactin on intercellular adhesion molecule-1 expression and monocyte/macrophage accumulation in the rat corpus luteum. Biology of Reproduction 64:890-897.
Wu Y-L, Wiltbank MC, 2001. Differential regulation of prostaglandin endoperoxide synthase-2 transcription in ovine granulosa and large luteal cells. Prostaglandin and Other Lipid Mediators, in press.
WILLIAMS, G. L., O. S. GAZAL, L. S. LESHIN, R. L. STANKO, and L. L. ANDERSON. 2001. Physiological regulation of maternal behavior in heifers: roles of genital stimulation, intracerebral oxytocin release, and ovarian steroids. BIOLOGY OF REPRODUCTION 65:295-300.
KIM, K.-S., J.M. REECY, L.L. ANDERSON and M.F. ROTHSCHILD. 2001. Functional characterization of the missense variation in the porcine melanocortin-4 receptor gene associated with obesity-related traits in the pig. PROCEEDINGS OF THE PLANT & ANIMAL GENOME IX, Page 210. (San Diego)
CHO, S.-J., K. JEFTINIJA, A. GLAVASKI, S. JEFTINIJA, B.P. JENA and L.L. ANDERSON. 2001. Fusion pores in GH-secreting cells. 31st Annual Meeting of the SOCIETY FOR NEUROSCIENCE, Nov. 10-15, 2001. PROCEEDINGS OF SOCIETY FOR NEUROSCIENCE 27:Abstract (San Diego)
CAAMAQO, J. N., S. OOKUTSU, M. L. PUGH, L. L. TIMMS, L. L. ANDERSON, P. M. DIXON and C. R. YOUNGS. 2001. Effect of FSH treatment on the developmental competence of oocytes recovered from postpartum dairy cows. 27th Annual Conference of the INTERNATIONAL EMBRYO TRANSFER SOCIETY (IETS), Jan. 14-16, 2001. Abstract (Omaha)
WILSON, M.E., K.A. VONNAHME and S.P. FORD. 2001. Role of altered uterine-embryo synchrony on conceptus growth in the pig. J. Anim. Sci. (In Press).
VONNAHME, K.A., M.E. WILSON and S.P. FORD. 2001. Relationship between placental vascular endothelial growth factor expression and placental/endometrial vascularity in the pig. Biol. Reprod. 64:1821-1825.
YOUNGS, C.R. 2001. Factors influencing the success of embryo transfer in the pig. THERIOGENOLOGY 56:1311-1320.
SIEREN, K.R. 2001. The Use of BoviPure for the separation of X and Y chromosome-bearing bovine sperm cells. M.S. Thesis, Iowa State Univ., 61 pp.
YOUNGS, C.R. 2001. Cattle breeding in the 21st century. Proc. Of the 30th Annual Cornbelt Cow-Calf Conference, Feb. 24, Ottumwa, IA, pp. 1-9.
DIKEMAN, M.A., D.R. STROHBEHN, and C.R. YOUNGS. 2001. Development of a web-based scheduling program for synchronization of estrus in cattle. JOURNAL OF ANIMAL SCIENCE 79(Suppl. 2):15 (abstr.)
FUNK, D.J. and C.R. YOUNGS. 2001. Embryo transfer, in vitro fertilization, cloning and transgenic production in farm animals: A review. Proc. Of the Student American Veterinary Medical Association Symposium, March 8-10, Ames, IA, p. 89 (abstr.)
PUGH, M.L., K.R. SIEREN, L.L. TIMMS, and C.R. YOUNGS. 2001. Use of a vaginal mucus electrical resistance probe to alter insemination time and calf gender distribution in dairy heifers. JOURNAL OF DAIRY SCIENCE 84(Suppl. 1):64 (abstr.).
Cartmill, J.A., S.Z. El-Zarkouny, B.A. Hensley, G.C. Lamb, and J.S. Stevenson. 2001. Stage of cycle, incidence and timing of ovulation , and pregnancy rates in dairy cattle after three timed breeding protocols. J. Dairy Sci. 84:84:1051-1059.
Lamb, G.C., J. S. Stevenson, D. J. Kesler, H.A. Garverick, D.R. Brown, and B. E. Salfen. 2001. Inclusion of an intravaginal progesterone insert plus GnRH and prostaglandin F2 for ovulation control in postpartum suckled beef cows. J. Anim. Sci. In press.
Medina-Britos, M.A., A.M. Richardson, G.C. Lamb, C.R. Dahlen, S.K. Johnson, S.Z. El-Zarkouny, B.A. Hensley, and J.S. Stevenson. 2001. Ovulation synchronization using progestins, GnRH, and PGF2 before timed AI (TAI) and resetting follicular waves for resynchronization of repeat inseminations of suckled beef cattle. J. Anim. Sci. 79(Suppl. 1):249-250 (Abstr. #1031).
Richardson, A.M., B.A. Hensley, and J.S. Stevenson. 2001. Characteristics of estrus before and after insemination and fertility after estrus synchronization with GnRH , PGF2, and progesterone in dairy heifers. J. Dairy Sci. 84:(Suppl. 1):249 (Abstr. #1029).
Stevenson, J.S. 2001. Incidence of anestrous in suckled beef cows and milked dairy cattle. J. Anim. Sci. 79(Suppl. 1):116 (Abstr. #481).
Johnson, S.K., J.S. Stevenson, K.R. Harmoney, and J.R. Brethour. 2001. Effects of pre and/or postpartum fat supplementation on reproduction in mature beef cows. J. Anim. Sci. 79(Suppl. 1):275 (Abstr. #1136).
El-Zarkouny, S.Z., J.A. Cartmill, A.M. Richardson, M.A. Medina-Britos, B.A. Hensley, and J.S. Stevenson. 2001. Presynchronization of estrous cycles in lactating dairy cows with Ovsynch + CIDR and resynchronization of repeat estrus using the CIDR. J. Dairy Sci. 84:(Suppl. 1):249 (Abstr. #1028).
Pursley, J.P., P.M. Fricke, H.A. Garverick, D.J. Kesler, J.S. Ottobre, J.S. Stevenson, and M.C. Wiltbank. 2001. Improved fertility in noncycling lactating dairy cows treated with progesterone during Ovsynch. Midwest ADSA/ASAS Mtg., Des Moines, IA, March19-21 (Abstr. #251).
Cartmill, J. A., S. Z. El-Zarkouny, B.A. Hensley, G.C. Lamb, and J.S. Stevenson. 2001. Stage of cycle, incidence and timing of ovulation , and pregnancy rates in dairy cattle after three timed breeding protocols. J. Dairy Sci. 84:1051-1059.
Dahlen, C.R., G.C. Lamb, B. Lindsay, A. DiCostanzo, D.R. Brown, A.R. Spell, and L.R. Miller. 2001. Pregnancy rates in recipients after receiving either two-identical demi-embryos or a single whole embryo. Theriogenology (In Press).
Medina-Britos, M.A., A.M. Richardson, G.C. Lamb, C.R. Dahlen, S.K. Johnson, S.Z. El-Zarkouny, B.A. Hensley, and J.S. Stevenson. Ovulation synchronization using progestins, GnRH, and PGF2 before timed AI (TAI) and resetting follicular waves for resynchronization of repeat inseminations of suckled beef cattle. J. Anim. Sci. 79(Suppl. 1):249.
Spell, A.R., W.R. Beal, L.R. Corah, and G.C. Lamb. 2001. Evaluating recipient and embryo factors that affect pregnancy rates of embryo transfer in beef cattle. Theriogenology 56:287-298.
Laughlin, M.H., W.G. Schrage, R.M. McAllister, H.A. Garverick and A.W. Jones. 2001. Interaction of gender and exercise training: vasomotor reactivity of porcine skeletal muscle arteries. J. Applied Physiology 90:216-227.
Calder, M.D., M. Manikkam, B.E. Salfen, R.S. Youngquist, D.B. Lubahn, W.R. Lamberson and H.A. Garverick. 2001. Dominant voine ovarian follicular cysts express increased levels of messenger RNAs for luteinizing-hormone receptor and 3-hydroxysteroid dehydrogenase 4, 5 isomerase compared to normal dominant follicles. Biol. Reprod. 65:471-476.
Salfen, B.E., F.N. Kojima, J.F. Bader, M.F. Smith and H.A. Garverick. 2001. Effect of short-term calf removal at three stages of a follicular wave on fate of a dominant follicle in postpartum beef cows. J. Anim. Sci. (in press).
M. Manikkam, M.D. Calder, B.E. Salfen, R.S. Youngquist, D.H. Keisler, and H.A. Garverick. 2001. Concentrations of steroids and gene expression of steroidogenic enzymes and gonadotropin receptors in bovine ovarian follicles of first and second waves and changes in second wave follicles after pulsatile LH infusion. Anim. Reprod. Sci. 67:189-203.
Hampton, J.H., M. Manikkam, D.B. Lubahn, M.F. Smith and H.A. Garverick. 2001. Androgen receptor mRNA expression inbovine ovarian follicles. Annual Mt Society of Study Reprod., Ottowa, Canada. July.
Pursley, J.R., P.M. Fricke, H.A. Garverick, D.J. Kesler, J.S. Ottober, J.S. Stevenson and M.C. Wiltbank. 2001. Improved fertility in noncycling lactating dairy cows treated with exogenous progesterone during ovsynch. NC-113 Regional Research Project. American Society of Animal Science and American Dairy Science Assoc. Midwest Section Annual Mtg, March.
Ching, S., D.C. Mahan, J.S. Ottobre, and K. Dabrowski. 2001. Ascorbic acid synthesis in fetal and neonatal pigs and in pregnant and postpartum sows. J. Nutrition 131:1997-2001.
Glogowski, J., J. Jankowski, A. Faruga, J.S. Ottobre, and A. Ciereszko. 2001. Acrosin activity in turkey spermatozoa: assay by clinical method and effect of zinc and benzamidine on the activity. Theriogenology 56:889-901.
Sartori R, Fricke P, Ferreira JCP, Ginther OJ, Wiltbank MC, 2001. Follicular deviation and acquisition of ovulatory capacity in bovine follicles. Biology of Reproduction 65:1403-1409.
Cordoba MC, Sartori R, Fricke PM, 2001. Assessment of a commercially available Early Conception Factor (ECF) test for determining pregnancy status of dairy cattle. Journal of Dairy Science 84:1884-1889.
Tsai SJ, Wiltbank MC, 2001 Differential effects of prostaglandin F-2 alpha on in vitro luteinized bovine granulosa cells. Biology of Reproduction. 122:245-253.
Vasconcelos JLM, Sartori R, Oliveira HN, Guenther JG, Wiltbank MC, 2001. Reduction in size of the ovulatory follicle reduces subsequent luteal size and pregnancy rate. Theriogenology. 56:307-314.
Beg MA, Bergfelt DR, Kot K, Wiltbank MC, Ginther OJ, 2001. Follicular-fluid factors and granulosa-cell gene expression associated with follicle deviation in cattle. Biology of Reproduction 64:432-441.
Wu Z, Kanneganti VR, Massingill LJ, Wiltbank MC, Walgenbach RP, Satter LD, 2001. Milk production of fall-calving dairy cows during summer grazing of grass or grass-clover pasture. Journal of Dairy Science. 84:1166-1173.
Olson KK, Anderson LE, Wiltbank MC, Townson DH, 2001. Action of prostaglandin F2a and prolactin on intercellular adhesion molecule-1 expression and monocyte/macrophage accumulation in the rat corpus luteum. Biology of Reproduction 64:890-897.
Wu Y-L, Wiltbank MC, 2001. Differential regulation of prostaglandin endoperoxide synthase-2 transcription in ovine granulosa and large luteal cells. Prostaglandin and Other Lipid Mediators, in press.