Exogenous PGF2α enhanced GnRH-induced LH release in postpartum cows

Randel, R.D.; Lammoglia-Villagómez, Miguel Ángel; Lewis, Andy; Neuendorff, D. A.; Guthrie, M. J.

doi:10.1016/0093-691x(95)00410-a

Cited by 48 publications

(30 citation statements)

References 28 publications

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“…Although injectable PGF has been shown to induce ovulation (Leonardi et al, 2012), its mechanism of action still needs to be clarified. A previous report showed an increased frequency of LH release, 6 hours after treatment with a PGF analogue, in anestrous cows (Randel et al, 1996). None of the follicles ovulated with a blood flow score smaller than 3, and the vascularization score of the largest follicles of the three cows from subgroup that failed to ovulate remained below 2, during all of the evaluated periods.…”

Section: Resultsmentioning

confidence: 99%

“…Treatment with PGF concurrent with AI could increase pregnancy rates by increasing uterine contractility (Stolla & Schmid, 1990), thereby enhancing sperm transport (Garcia-Ispierto & Lópes-Gatius, 2014;Ambrose et al, 2015), inducing the luteinizing hormone (LH) release via a luteolysis-independent mechanism (Randel et al, 1996), and therefore, assisting the ovulatory process or hastening the luteal regression (Ambrose et al, 2015). Although the effects PGF given 24 hours after the progesterone device removal on hastening luteolysis has been studied (Bisinotto et al, 2010;Santos et al, 2010;Lima et al, 2013;Garcia-Ispierto & Lópes-Gatius, 2014), to our knowledge, no study was performed to investigate whether PGF can induce ovulation by itself in TAI protocols for dairy cows.…”

Section: Introductionmentioning

confidence: 99%

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Prostaglandin F2α or estradiol benzoate to induce ovulation in timed artificially inseminated dairy cows

Pfeifer

Siqueira

Arashiro

et al. 2016

Pesq. agropec. bras.

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-The objective of this work was to compare two types of ovulation inducers -estradiol benzoate (EB group) or prostaglandin F2α (PG group) -, in postpartum dairy cows subjected to timed artificial insemination (TAI). Lactating Holstein-Gir crossbred cows (n=118) with 60 to 120 days of milk production were used in this study. All cows were treated with an intravaginal progesterone-releasing device (CIDR) plus 2 mg of estradiol benzoate (EB) on day 0. The CIDR inserts were removed on day 9, and all cows received 500 µg sodium cloprostenol. Twenty-four hours after CIDR removal, cows were randomly assigned into two treatment groups and were given either 1 mg of EB i.m. (EB group) or 500 µg sodium cloprostenol i.m. (PG group). TAI were performed at 52 to 54 hours, in both EB and PG groups, after CIDR removal. No differences were observed in the ovulation (85.2% vs 72.7%) and pregnancy rates (40.7% vs 38.2%) between the EB and PG groups, respectively. Fertility is similar in the TAI protocols that use prostaglandin F2α or EB to induce ovulation in lactating dairy cows.Index terms: artificial insemination, cattle, estrus, synchronization, withdrawal period. Prostaglandina F2α ou benzoato de estradiol para induzir a ovulação em vacas leiteiras inseminadas em tempo fixoResumo -O objetivo deste trabalho foi comparar dois indutores de ovulação -benzoato de estradiol (grupo BE) ou prostaglandina F2α (grupo PG) -, em vacas leiteiras pós-parto submetidas à inseminação artificial em tempo fixo (IATF). Neste estudo, utilizaram-se vacas Girolando lactantes (n=118) com 60 a 120 dias em lactação. Todas as vacas foram tratadas com um implante intravaginal liberador de progesterona (CIDR) associado a 2 mg de benzoato de estradiol (BE) no dia 0. O CIDR foi retirado no dia 9, e todas as vacas receberam 500 µg i.m. de cloprostenol sódico (análogo à prostaglandina F2α Termos para indexação: inseminação artificial, bovinos, estro, sincronização, período de carência.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Prostaglandin F2α or estradiol benzoate to induce ovulation in timed artificially inseminated dairy cows

Pfeifer

Siqueira

Arashiro

et al. 2016

Pesq. agropec. bras.

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“…Lopez‐Gatius and Lopez‐Bejar (2002) used ovsynch protocols similar to those applied in this study and also achieved a better cure rate with the modified ovsynch than the conventional protocol (89% vs. 53%, p < 0.001). As a possible explanation, the authors assumed synergistic effects of GnRH and PGF on the luteinization of follicular cysts, because in earlier studies, the exogenous administration of PGF was able to cause an increase in LH secretion from the pituitary gland (Hanzen 1984) and to enhance the GnRH‐induced LH release in pp cows (Randel et al. 1996).…”

Section: Discussionmentioning

confidence: 99%

Comparison of Two Different Programmes of Ovulation Synchronization in the Treatment of Ovarian Cysts in Dairy Cows

Gundling

Drews

Hoedemaker

2015

Reprod Domestic Animals

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It was the aim of this field study to evaluate two different protocols of ovulation synchronization for the treatment of ovarian cysts and their effect on reproductive performance in dairy cows. In addition, factors with a possible influence on treatment success and pregnancy outcome as well as costs per pregnancy were analysed. The study was performed with 130 German Holsteins with ovarian cysts diagnosed on days 55 to 60 postpartum. Cows belonging to group 1 (n = 65) received a modified ovsynch protocol [day 0: 0.15 mg cloprostenol (PGF) + 0.02 mg buserelin acetate (GnRH); day 14: PGF; day 16: GnRH]. Group 2 (n = 65) was treated with the conventional ovsynch protocol (day 0: GnRH; day 7: PGF; day 9: GnRH). Timed artificial insemination was performed 20 to 24 h later. Cows without ovarian cysts served as controls. Treatment success (disappearance of the ovarian cyst) after the first ovsynch cycle was higher in group 1 (66.2%) than in group 2 (23.1%, p < 0.05). Reproductive measures in group 1 were comparable with those of the control group and, compared with group 2, were conspicuously better (66.2%, 76.9%, 83.1%, 59.5% vs. 40.0%, 50.7%, 60.0%, 27.5% for cumulative pregnancy rate after treatment cycle 1 to 3 and second service conception rate, respectively, p < 0.05). Overconditioned cows and cows with larger ovarian cysts showed a diminished treatment and pregnancy success. In group 1, costs per pregnancy were only slightly higher than in the control group (group 1: €352.44, group 2: €484.59, control group: €333.77). In conclusion, our results suggest that ovsynch protocols can be used in the treatment of ovarian cysts. The modified ovsynch protocol led to a better cure rate as well as a better reproductive performance, and was economically beneficial compared with a conventional ovsynch protocol.

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“…Studies have shown that prostaglandins PGF2α and PGE2 mediate direct effect on the hypothalamic-pituitary axis causing FSH peak [34,35], suggesting that since ibuprofen could inhibit cyclooxygenase enzyme that is the dominant source prostaglandins, thereby attenuating prostaglandin release causing the reduction of FSH in the present study. The significant reduction in FSH level also corroborated with our previous work that showed significant reduction in FSH level in ibuprofen-treated rats [35]. Figure 1 showed that extract and ibuprofen caused significant reduction in the serum LH level respectively.…”

Section: Discussionmentioning

confidence: 72%

A Comparative Study between Xylopia aethiopica Dried Fruit Extract and Ibuprofen Inhibiting Effects on Some Reproductive Hormones Irrespective of the Estrous Cycle

Onuka

Okechukwu

Maxine

2017

IJCAM

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Ibuprofen is often used for contraception, therefore, Xylopia aethiopica dried fruit extract and ibuprofen were tested on follicle-stimulating hormone (FSH), luteinizing hormone (LH), glucocorticoid, progesterone and estrogen levels in adult female rats in order to determine whether Xylopia aethiopica dried fruit extract can be used for contraception. Twenty one rats were randomly divided into 3 groups (n = 7) comprising of control group A, experimental Group B and C. The experimental Group B received 180 mg/kg of ibuprofen daily and experimental Group C received 300 mg/kg of Xylopia aethiopica dried fruit extract. All administration of drug and extract was done via oral route and lasted for 14 days independent of estrous cycle. Using Enzyme-linked Immunosorbent Assay the serum FSH, LH, glucocorticoid, progesterone and estrogen in both extract and ibuprofen treated rats were measured. Results showed that ibuprofen caused significant reduction of FSH (P<0.05). The extract did not cause significant difference in the serum FSH level. Both ibuprofen and extract caused significant reduction (P<0.05) in the serum LH levels. Both ibuprofen and extract caused significant elevation (P< 0.05) in glucocorticoid level. However, the extract caused significant reduction (P<0.05) in the serum progesterone and estrogen levels respectively compared to ibuprofen. In that sense, Xylopia aethiopica dried fruit extract acted as a more potent contraceptive, inhibitor of ovulatory hormones than ibuprofen. and selectively blocks estrogen-mediated receptors in rats [7]. Moreover, the use of synthetic steroidal contraceptives has proven unsafe to the health of the user as they pose risk of side effects [8][9][10]. Keywords:In Africa, traditional methods of contraception are on the increase and have been increasingly sought for in herbal plants because herbs are effective, cheap and safe [11] [16,17]. Meanwhile, in ancient times, women drank extracted water from Xylopia aethiopica as a natural method of contraception that became part of Igbo folklore and this led to the present research work. The plant, Xylopia aethiopica commonly known as "Uda" in Igbo language, "Eeru alamo" in Yoruba language and "Chimba" in Hausa language is a tropical evergreen, aromatic plant that grows commonly in wet swampy soils and forest zones of West Africa characterized with a slim tall tree of about 15 -30 m tall and 0.6 -0.7 m in diameter, straight stem, slightly stripped or smooth bark with consistent pepperish aroma with dry brown, corrugated in shape with pods containing 4 -9 kidney shaped peppery seeds about 0.05 m in length [18,19].However, antifertility effect of Xylopia aethiopica have been demonstrated in male rats [20,21]. In another study unpublished, we demonstrated that Xylopia aethiopica dried fruit extract caused alteration in luteinizing hormone (LH), follicle-stimulating hormone (FSH), and glucocorticoid hormone during proestrus phase of clomiphene-treated rats. Because Xylopia aethiopica have analgesic properties and can be used in t...

show abstract

Exogenous PGF2α enhanced GnRH-induced LH release in postpartum cows

Cited by 48 publications

References 28 publications

Prostaglandin F2α or estradiol benzoate to induce ovulation in timed artificially inseminated dairy cows

Prostaglandin F2α or estradiol benzoate to induce ovulation in timed artificially inseminated dairy cows

Comparison of Two Different Programmes of Ovulation Synchronization in the Treatment of Ovarian Cysts in Dairy Cows

A Comparative Study between Xylopia aethiopica Dried Fruit Extract and Ibuprofen Inhibiting Effects on Some Reproductive Hormones Irrespective of the Estrous Cycle

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