Effect of time interval between prostaglandin F2α and GnRH treatments on occurrence of short estrous cycles in cyclic dairy heifers and cows

Rantala, Mari H.; Katila, Terttu; Taponen, Juhani

doi:10.1016/j.theriogenology.2008.10.014

Cited by 13 publications

(12 citation statements)

References 20 publications

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“…In beef cattle, induction of the first post-partum ovulation by early weaning or temporary calf removal or by using hormonal treatments, such as GnRH or hCG, results in a high percentage of cows with short cycles, whereas pretreatment with P4 or progestogens before these induction procedures prevents these short cycles (Copelin et al, 1988;Salfen et al, 1995). Finally, in cycling dairy heifers or cows, a high percentage of short cycles is induced if cows are given a premature treatment with GnRH following induction of luteolysis with PGF (0 or 24 h after PGF given on day 6 or 7 of the estrous cycle; Peters and Pursley, 2003;Rantala et al, 2009). Each of these models is characterized by inadequate circulating E2 during the proestrous period, generally ovulation of a smaller follicle, production of a CL with a shortened lifespan, and a short estrous cycle.…”

Section: Period I: Short Luteal Phase and Early CL Regression -Day 5-7mentioning

confidence: 99%

“…Reduced preovulatory E2 can produce a short CL lifespan (Vasconcelos et al, 2001;Peters and Pursley, 2003;Rantala et al, 2009), even in animals with elevations in P4 prior to the preovulatory period. However, supplementation of early postpartum beef cattle with E2 alone was not sufficient to restore normal luteal phases but they required both elevated P4 prior to the preovulatory period and elevated E2 during the preovulatory period to have normal CL lifespan (Sa et al, 2009).…”

Section: Period I: Short Luteal Phase and Early CL Regression -Day 5-7mentioning

confidence: 99%

See 1 more Smart Citation

Maintenance or regression of the corpus luteum during multiple decisive periods of bovinepregnancy

Wiltbank¹,

Meidan²,

Ochoa³

et al. 2016

Anim Reprod

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In ruminants, there are specific times during the estrous cycle or pregnancy when the corpus luteum (CL) may undergo regression. This review has attempted to summarize the physiological and cellular mechanisms involved in CL regression or maintenance during four distinct periods. The first period is near day 7 when animals that are ovulating after a period of low circulating progesterone (P4), such as first pubertal ovulation or first postpartum ovulation, are at risk of having a premature increase in Prostaglandin F2α (PGF) secreted from the uterus resulting in early CL regression and a short estrous cycle. The second period is when normal luteolysis occurs at day 18-25 of the cycle or when the CL is rescued by interferon-tau secreted by the elongating embryo. The uterine mechanisms that determine the timing of this luteolysis or the prevention of luteolysis have been generally defined. Induction and activation of endometrial E2 receptors result in induction of endometrial oxytocin receptors that can now be activated by normal pulses of oxytocin. Of particular importance is the observation that the primary mechanisms are only activated through local (ipsilateral) and not a systemic route due to transfer of PGF from the uterine vein to the ovarian artery. In addition at the CL level, studies are providing definition to the cellular and molecular mechanisms that are activated in response to uterine PGF pulses or pregnancy. The third period that is discussed occurs in the second month of pregnancy (day 28-60) when undefined mechanisms result in CL maintenance of an ipsilateral CL but regression of a contralateral (opposite side from pregnancy) CL. The final period that is discussed is regression of the CL just prior to parturition. Although, cortisol from the fetus appears to be the primary initiator of luteolysis, PGF seems to be the final signal that causes regression of the CL. Thus, in all four periods, regression of the CL is likely to be caused by the direct actions of PGF that is secreted from the uterus. The uterine mechanisms that result in secretion of PGF seem to be normally inhibited during the early luteal phase, making short luteal phases not a normal event, and are altered during early pregnancy (day 18-25) resulting in prevention of luteolysis. During much of pregnancy, the mechanisms that cause PGF secretion from the uterus in response to oxytocin are intact but luteolysis does not normally occur, perhaps due to lack of efficient utero-ovarian transfer of PGF.

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Section: Period I: Short Luteal Phase and Early CL Regression -Day 5-7mentioning

confidence: 99%

Section: Period I: Short Luteal Phase and Early CL Regression -Day 5-7mentioning

confidence: 99%

Maintenance or regression of the corpus luteum during multiple decisive periods of bovinepregnancy

Wiltbank¹,

Meidan²,

Ochoa³

et al. 2016

Anim Reprod

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“…Die vorliegende Untersuchung liefert Angaben zur Sonomorphologie des Corpus luteum nach spontaner und induzierter Ovulation sowie nach spontaner und induzierter Luteolyse. Es wurde ein Brunstinduktionsverfahren gewählt (Simultaninjektion von GnRH und PGF 2α [11,13]), dessen Auswirkungen auf die Sonomorphologie des Gelbkörpers noch nicht beschrieben sind. Die in dieser Studie erhobenen Daten stimmen mit Angaben aus der Literatur zur Entwicklung des Gelbkörpers nach induzierter und spontaner Ovulation sowie Luteolyse überein.…”

Section: Fazit Für Die Praxisunclassified

Sonographische Darstellbarkeit des Corpus luteum bei der Milchkuh

Röskes¹,

Failing²,

Wehrend³

2012

Tierarztl Prax Ausg G

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Zusammenfassung Ziel der Untersuchungen war zu überprüfen, ab welchem Zeitpunkt post ovulationem das Corpus haemorrhagicum bei der Milchkuh nach spontaner oder induzierter Ovulation mit einem mobilen Ultraschallgerät sicher dargestellt werden kann. Material und Methoden: Während drei unbeeinflusster sowie drei durch die simultane Applikation von GnRH und PGF2α an den Zyklustagen 7, 14 oder 17 post ovulationem medikamentös verkürzter Zyklen wurde bei sechs Kühen die Ovardynamik dargestellt. Dazu erfolgte eine tägliche sonographische Untersuchung der Ovarien in den unbeeinflussten Zyklen ab dem 18. Zyklustag und in den Zyklen mit Behandlung ab dem Zeitpunkt der Hormongabe. Nach der Ovulation wurden die sich anbildenden Corpora lutea alle 48 Stunden sonographisch dargestellt. Eine Bestimmung der Progesteronkonzentration fand am 1. Zyklustag, am Tag der Hormongabe und in den folgenden 5 Tagen statt, um die sonographischen Befunde durch endokrine Werte abzusichern. Ergebnisse: Ab dem 5. Tag post ovulationem ließ sich das Corpus luteum in 100% der Fälle sowohl nach spontaner als auch nach induzierter Ovulation sicher darstellen. Eine sonographisch sichtbare Verkleinerung des Gelbkörpers nach induzierter Luteolyse begann in den Zyklen mit Behandlung 1,3–1,8 Tage nach der Hormoninjektion und war nach durchschnittlich 3,7 Tagen abgeschlossen. Auf die Darstellbarkeit der Gelbkörperrückbildung hatte der Zeitpunkt der Hormoninjektion im Zyklus keinen Einfluss. In 33% der Fälle wies das Corpus luteum einen zentralen flüssigkeitsgefüllten Hohlraum auf, der sich während der Luteolyse zurückbildete. Schlussfolgerung und klinische Relevanz: Die sonographische Darstellung des Gelbkörpers ist ab dem 5. Tag post ovulationem sicher möglich. Weiterhin kann der Erfolg einer eingeleiteten Luteolyse sonographisch verifiziert werden. Somit eignet sich das Verfahren zur Erfolgskontrolle einer induzierten Ovulation.

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“…Based on the serum concentrations of progesterone from d 0 to 20 and estrous data, cows were classified as cycling or anestrus (serum concentrations of progesterone remained below 1.0 ng/mL for the duration of the experiment). The cycling cows were further separated into cows with a normal estrous cycle (≥16 d) or cows with a short estrous cycle (<16 d; Rantala et al, 2009).…”

Section: Resumption Of the Estrous Cyclementioning

confidence: 99%

Factors affecting preovulatory follicle diameter and ovulation rate after gonadotropin-releasing hormone in postpartum beef cows. Part II: Anestrous cows1

Atkins

Smith

Wells

et al. 2010

Journal of Animal Science

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There is large variation in dominant follicle diameter at the time of GnRH-induced ovulation in the CO-Synch protocol [a first GnRH injection on d -9 (GnRH1), followed by PGF(2alpha) on d -2, and a second GnRH injection (GnRH2) with timed AI on d 0], and the reason for the presence of small dominant follicles at GnRH2 is not known. Our hypothesis was that ovulatory response to GnRH1 and progesterone exposure [controlled intravaginal drug-releasing insert (CIDR; EAZI-Breed, Pfizer Animal Health, New York, NY)] would affect ovulatory follicle size at GnRH2 in anestrous cows. This study used a 2 x 2 factorial arrangement of treatments in which anestrous suckled beef cows (n = 55) either ovulated (Ov1+) or failed to ovulate (Ov1-) after GnRH1 and either received (CIDR+) or did not receive (CIDR-) a 7-d CIDR treatment (from GnRH1 to PGF(2alpha)), resulting in the following treatment groups: Ov1+CIDR+, Ov1-CIDR+, Ov1+CIDR-, and Ov1-CIDR- (n = 9, 17, 11, and 18, respectively). The Ov1+ cows had larger follicles at GnRH2 (12.3 vs. 11.0 mm; P = 0.04), a decreased proportion of small follicles within cows that ovulated to GnRH2 (2/16 vs. 14/23; P = 0.003), and a similar growth rate of the ovulatory follicle from d -5 to 0 (d 0 = GnRH2; 1.1 +/- 0.06 vs. 1.1 +/- 0.07 mm/d; P = 0.99) compared with Ov1- cows. Administration of a CIDR had no effect on follicle diameter at GnRH2 (11.8 vs. 11.2 mm; P = 0.3), proportion of small ovulatory follicles at GnRH2 (7/19 vs. 9/20; P = 0.6), and follicular growth rate from d -5 to 0 (d 0 = GnRH2; 1.2 +/- 0.07 vs. 1.1 +/- 0.07 mm/d; P = 0.76). Administration of a CIDR, but not ovulation to GnRH1, increased follicle growth from d -2 to 0 (d 0 = GnRH2; P = 0.03 and 0.9, respectively). Large follicles (>11 mm) had a similar growth rate from d -5 to 0 (d 0 = GnRH2; P = 0.44) compared with small follicles (1.1 +/- 0.07 vs. 1.2 +/- 0.07 mm/d), but the large ovulatory follicles were larger at d -5 compared with small ovulatory follicles (P < 0.001). Follicle diameter was positively correlated with serum concentrations of estradiol at GnRH2 (r = 0.622; P < 0.0001). In summary, ovulation to GnRH1, but not CIDR administration, resulted in increased dominant follicle diameter at GnRH2 in anestrous suckled beef cows. Large follicles were already larger 5 d before GnRH2 but grew at a rate similar to small follicles; follicle size was positively correlated with serum concentrations of estradiol at the time of GnRH-induced ovulation.

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Effect of time interval between prostaglandin F2α and GnRH treatments on occurrence of short estrous cycles in cyclic dairy heifers and cows

Cited by 13 publications

References 20 publications

Maintenance or regression of the corpus luteum during multiple decisive periods of bovinepregnancy

Maintenance or regression of the corpus luteum during multiple decisive periods of bovinepregnancy

Sonographische Darstellbarkeit des Corpus luteum bei der Milchkuh

Factors affecting preovulatory follicle diameter and ovulation rate after gonadotropin-releasing hormone in postpartum beef cows. Part II: Anestrous cows1

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