Is it possible to replace eCG by GnRH in the hormonal protocol for timed artificial insemination in ewes during the breeding season?

Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0-5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 106 motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.

Effect of an equine chorionic gonadotrophin-like recombinant glycoprotein treatment on fertility in Angus cattle.

This study determined the effects of administering a glycoprotein with equine chorionic gonadotropin (eCG)-like activity (eCG-like) on corpus luteum (CL) area, serum progesterone concentrations, incidence of multiple ovulations (MOV), estrus expression rate (EER), and pregnancy to timed AI (P/TAI) in Angus cattle synchronized with a 5-d Co-Synch protocol. On Day -8, cattle were body condition scored (BCS), and received a 1.0 g progesterone intravaginal device (IVD) and 100 µg GnRH. On Day -3, the IVDs were removed and 500 µg cloprostenol was administered intramuscularly (i.m.). Cattle were randomly assigned into one of two groups: eCG-like (heifers, n = 232, primiparous, n = 148, and multiparous cows = 485; 300 IU (heifers) and 400 IU (cows) eCG-like i.m. on Day -3), or Control (heifers, n = 240, primiparous, n = 151, and multiparous cows, n = 478; no eCG-like). On Day -2, cattle received a second dose of 500 µg cloprostenol, and on Day 0, 100 µg GnRH was given concurrently with TAI. Estrus expression rate was assessed by observing the tail paint rubbed off in a subset of heifers (n = 372) and all cows on Day 0. Transrectal ultrasonography was used to evaluate the presence of CL on Day -8 and to diagnose P/TAI on Day 30-35. In a subset of cattle (heifers = 194 and multiparous cows = 87), CL area, serum progesterone concentrations, and incidence of MOV were evaluated on Day 7. Heifers, primiparous, and multiparous cows were analyzed separately. Treatment with eCG-like did not affect (P > 0.1) EER in heifers. Estrus expression rate was increased (P ≤ 0.03) in primiparous (68.9 % vs 45.0 %) and multiparous (75.5 % vs. 68.8 %) cows treated with eCG-like compared with Controls. Pregnancy/TAI was increased (P < 0.01) in heifers (65.2 % vs 48.3 %) and primiparous cows (48.3 % vs. 35.1 %) treated with eCG-like than Controls. In multiparous cows with a BCS ≤4 P/TAI was increased (P = 0.03) in the eCG-like group (47.7 %) than the Control group (34.8 %) but was similar (P > 0.1) between treatment groups in multiparous cows with a BCS ≥4.5. The eCG-like treatment increased (P < 0.05) CL area in heifers and multiparous cows and tended (P = 0.10) to elevate serum progesterone concentrations only in heifers. However, it did not affect (P > 0.1) the incidence of MOV in heifers and multiparous cows. Glycoprotein eCG-like administration increased fertility in heifers and primiparous cows, but in multiparous the effect of eCG-like on fertility was associated with BCS.

The use of a recombinant equine chorionic gonadotropin (reCG) in fixed-time AI programs in beef cattle.

The aim of the current study was to evaluate the effect of a novel recombinant eCG (reCG) on pregnancy rates to AI (P/AI) in suckled beef cows of different breeds that were synchronized with an estradiol/progesterone (P4)-based protocol for fixed-time AI (TAI). In experiment 1, 1244 Bos taurus suckled cows were used. On Day 0 all cows received an intravaginal P4 device (600 mg P4) and 2 mg of estradiol benzoate. On Day 7, devices were removed, and all cows received 0.150 mg of D-cloprostenol plus 1 mg of estradiol cypionate and were randomly divided to receive 140 IU or 105 IU of reCG or no reCG treatment (controls) at that time. Cows were tail painted for estrus detection and those in estrus by 48 h after P4 device removal were inseminated; whereas those not showing estrus were also inseminated and received GnRH at the same time. In experiment 2, 818 Bos taurus x Bos indicus crossbred suckled cows received the same FTAI protocol used in Experiment 1. Cows were randomly divided at the time of P4 device removal into 4 groups to receive 140 IU, 105 IU or 84 IU of reCG or no reCG treatment. In experiment 3, 345 Bos indicus suckled cows were submitted to the same FTAI protocol as those in previous experiments and were randomly divided into three groups to receive 140 IU or 105 IU of reCG, or 300 IU of serum derived eCG (PMSG). In Experiment 1, estrus rate and P/AI was greater (P < 0.05) in cows treated with reCG (79.9 and 53.5 %, 76.9 and 52.3 % for the 105 UI and 140 UI reCG groups, respectively) than those in the control group (69.9 and 44.4 %, respectively). In Experiment 2, cows treated with reCG tended (P < 0.1) to achieve a greater P/AI than control cows (38.6 %, 37.1 %, 36.2 % and 28.2 % for those receiving 84 IU, 105 IU,140 IU of reCG, and those in the control group); but when P/AI of all cows treated with reCG was contrasted to that of control cows, the difference was significant (P < 0.01). In Experiment 3, P/AI in cows treated with 84 IU of reCG (54 %) did not differ from that of cows treated with serum derived eCG (59 %) but both were greater (P < 0.05) than cows treated with 105 UI of reCG (41 %). In conclusion, treatment with reCG improved fertility in suckled Bos taurus and Bos taurus x Bos indicus beef cows. In suckled Bos indicus cows, although treatment with reCG and serum derived eCG were comparable, the higher dosage of reCG was detrimental to their P/AI.

Equine chorionic gonadotropin (eCG) treatment in heifers: Double ovulation, twinning rate, and pregnancy losses in twin pregnancies.

This study aimed to evaluate the effects of different doses of equine chorionic gonadotropin (eCG; 200 and 300 IU) administered at the end of a fixed-time artificial insemination (FTAI) treatment protocol on ovulation, pregnancy, and twin rates in Bos taurus beef heifers. In addition, pregnancy losses in heifers with singleton and twin pregnancies were determined. A total of 2382 Angus heifers treated with a 6-day estradiol/progesterone-based protocol for FTAI (J-Synch protocol) were randomly allocated to two experimental groups to receive 200 or 300 IU of eCG administered intramuscularly at the time of intravaginal progesterone device removal; FTAI was performed from 60 to 72 h after device removal. The pregnancy rate did not differ (P = 0.89) between the 200 and 300 IU eCG groups. The number of corpus luteum induced by both eCG doses was determined by ultrasonographic examination 14 days after insemination and those treated with 300 IU of eCG had a greater double ovulation rate (P < 0.05). In addition, 300 IU eCG treated heifers had a higher twinning rate on day 30 of gestation (P < 0.05) and parturition (P < 0.05). Pregnancy losses from 30 days of gestation to calving did not differ between heifers treated with 200 and 300 IU of eCG (P = 0.70). However, regardless of the experimental group, heifers bearing twins had greater pregnancy losses than heifers with singletons (P < 0.05). In conclusion, reducing the dose of eCG from 300 to 200 IU under FTAI treatment protocol decreases double ovulation and twinning rates, maintaining a similar pregnancy rate in heifers. Nulliparous cows carrying two fetuses suffer greater pregnancy losses than cows with singletons.

Greater concentrations of IGF-1 are associated with increasing pregnancy rate in melatonin implanted anestrous Barki ewes.

The present study was conducted to determine if increases in IGF-1 concentration, associated with treatment of ewes with melatonin, has beneficial effects on pregnancy rates when there is induction of estrus in anestrous ewes. A total of 120 multiparous lactating ewes were assigned to three groups (n = 10/group). Ewes of Group 1 were treated with a melatonin implant for 42 days followed by insertion of a controlled internal drug release (CIDR) device for 14 days with administration of equine chorionic gonadotropin (eCG) at day of CIDR removal. The ewes of Group 2 were treated with a CIDR and eCG at the same times as ewes of Group 1 and ewes of Group 3 were assigned to an be untreated control group. Melatonin implantation resulted in an increase in IGF-1 concentrations and lesser estradiol (E2) and triiodothyronine (T3) concentrations. Ewes of Groups 1 and 2 had the greatest progesterone (P4) concentration compared ewes of Group 3. The E2:P4 ratio was less in ewes of Group 1 compared Group 3. Melatonin implantation of ewes resulted in a greater pregnancy rate compared to treatment with the CIDR and eCG which, in turn, had a greater rate than ewes of the control group. In conclusion, melatonin implantation modulates the hormonal milieu including P4, E2, T3 and IGF-1 in seasonally anestrous ewes. Increased IGF-1concentrations, as a result of melatonin treatment, are associated with a greater percentage pregnancy rate when there is treatment of anestrous ewes to induce onset of estrus.

Induction of synchronous oestrus but not ovulation after pre-treatment with the GnRH agonist, Lucrin® Depot, in the tammar wallaby.

We investigated the capacity for pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to induce synchronous oestrus and ovulation in the tammar wallaby (Notamacropus eugenii) after follicular suppression with Lucrin® Depot, a one-month GnRH agonist. On Day 0 pouch young were removed (RPY) to reactivate a normal oestrous cycle and then two groups were treated with vehicle (Control; n = 5 and Superovulation (SOvn); n = 5) and two groups were treated with 7.5 mg of Lucrin Depot (Lucrin; n = 6; Lucrin+SOvn, n = 6). On Day 20 RPY the SOvn and Lucrin+SOvn Group received 20 IU of PMSG, which was followed on Day 23 RPY with 500 IU of hCG. The Lucrin+SOvn females underwent a more synchronous oestrus with 5 of 6 mating on Day 26 RPY while the SOvn (n = 5/5) and Control (n = 5/5) Groups copulated over two days, between Day 25-27 RPY and Day 27-29 RPY respectively. Mating plugs were not detected in any of the females in the Lucrin Group by Day 31 RPY. Autopsy on Day 31 RPY confirmed all females in each treatment group had undergone a reactivated cycle as evidenced by the presence of a large corpus luteum (CL) in one ovary. At autopsy the females in the Lucrin+SOvn Group had highly stimulated reproductive tracts, and their ovaries contained many follicles >3 mm; 14 ± 2.1 and 15.3 ± 2.1 follicles >3 mm in the CL-bearing ovary and contralateral ovary respectively. Similarly, females in the SOvn Group had 11.4 ± 2.4 and 17.4 ± 1.9 follicles >3 mm in each respective ovary. Uterine flushing and ovarian histology confirmed that females in Lucrin+SOvn and SOvn Groups had not ovulated, but normal oocytes were present in the follicles. By comparison, the Control Group had ovulated with a single embryo being recovered from the uterus of 4 of 5 females. In contrast to all groups, females in the Lucrin Group showed follicular suppression (all follicles <1.5 mm) and an unstimulated reproductive tract. We conclude that a suppression plus stimulation regimen using Lucrin Depot followed by PMSG and hCG has the capacity to synchronise oestrus, and that 20 IU of PMSG stimulates the development of antral follicles >3 mm in both ovaries. However, a single 500 IU treatment of hCG on Day 23 RPY was not able to induce ovulation in the tammar wallaby.

Superovulation with human chorionic gonadotropin (hCG) trigger and gonadotropin releasing hormone agonist (GnRHa) trigger differentially alter essential angiogenic factors in the endometrium in a mouse ART model†.

Gonadotropin-releasing hormone agonists (GnRHa) are used as an alternative to human chorionic gonadotropin (hCG) to trigger ovulation and decrease the risk of ovarian hyperstimulation syndrome. GnRHa is less potent at inducing ovarian vascular endothelial growth factor (VEGF), but may also affect endometrial angiogenesis and early placental development. In this study, we explore the effect of superovulation on endometrial angiogenesis during critical periods of gestation in a mouse model. We assigned female mice to three groups: natural mating or mating following injection with equine chorionic gonadotropin and trigger with GnRHa or hCG trigger. Females were killed prior to implantation (E3.5), post-implantation (E7.5), and at midgestation (E10.5), and maternal serum, uterus, and ovaries were collected. During peri-implantation, endometrial Vegfr1 and Vegfr2 mRNA were significantly increased in the GnRHa trigger group (P < 0.02) relative to the hCG group. Vegfr1 is highly expressed in the endometrial lining and secretory glands immediately prior to implantation. At E7.5, the ectoplacental cone expression of Vegfa and its receptor, Vegfr2, was significantly higher in the hCG trigger group compared to the GnRHa group (P < 0.05). Soluble VEGFR1 and free VEGFA were much higher in the serum of mice exposed to the hCG trigger compared to GnRHa group. At midgestation, there was significantly more local Vegfa expression in the placenta of mice triggered with hCG. GnRHa and hCG triggers differentially disrupt the endometrial expression of key angiogenic factors during critical periods of mouse gestation. These results may have significant implications for placental development and neonatal outcomes following human in vitro fertilization.

Diferentes momentos de aplicação de gonadotrofina coriônica equina em protocolo de inseminação artificial em tempo fixo para vacas de leite / Different times of application of equine chorionic gonadotropin in fixed-time artificial insemination protocols for dairy cows

Avaliaram-se diferentes momentos de aplicação da gonadotrofina coriônica equina (eCG) em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de leite. Foram utilizadas 76 fêmeas, as quais receberam, no dia zero (D0) do protocolo, dispositivos intravaginais de progesterona, sendo esses retirados no D9, e os animais foram, então, distribuídos aleatoriamente em três tratamentos: T1 - aplicação de eCG no momento da retirada dos dispositivos; T2 e T3 - aplicação de eCG 48h e 24h antes da retirada dos dispositivos, respectivamente. No D10 os animais receberam 1mg de GnRH, e a IATF foi realizada 52 horas após a retirada do implante. Não houve diferença (P>0,05) para intervalo entre a retirada do implante à ovulação (72,56±3,92h), o diâmetro do maior folículo no D9 (10,88±1,49mm), o diâmetro do folículo ovulatório (15,15±1,16mm) e do segundo maior folículo (7,49±0,52mm), a taxa de crescimento folicular (1,38±0,04mm/dia), a taxa de ovulação (96,67%), o intervalo entre diâmetro final e inicial do folículo dominante (73,49±3,84h), a área de corpo lúteo (2,27±0,43cm²), a porcentagem de CL no ovário direito (53,00%) e no esquerdo (26,33%) e a taxa de gestação (33,33%). O momento da aplicação da eCG não influenciou na eficiência do protocolo. Recomenda-se a utilização da eCG no momento da retirada do implante por otimização do manejo.(AU)

Different times of application of equine chorionic gonadotropin (eCG) in Fixed-Time Artificial Insemination (FTAI) protocols for dairy cows were evaluated. A total of 76 females were used, which received intravaginal progesterone devices on day zero (D0) of the protocol, which were withdrawn on D9, and the animals were then randomly distributed in three treatments: T1- application of eCG at the time of device withdrawal; T2 and T3 - application of eCG 48h and 24h before withdrawal of the devices, respectively. On D10 the animals received 1mg of GnRH and the FTAI was carried out 52 hours after the removal of the implant. There was no difference (P>0.05) for interval from implant removal to ovulation (72.56±3.92h), diameter of the largest follicle of D9 (10.88±1.49mm), diameters of ovulatory follicle (15.15±1.16mm) and of the second largest follicle (7.49±0.52mm), follicle growth rate (1.38±0.04mm/day), ovulation rate (96.67%), interval between final diameter and initial diameter of dominant follicle (73.49±3.84h), corpus luteum area (2.27±0.43cm²), percentage of CL in right ovary (53.00%) and in left ovary (26.33%) and pregnancy rate (33.33%). The time of the application of eCG did not influence the efficiency of the protocol. We recommend the use of eCG at the time of the removal of the implant for management optimization.(AU)

Onset of oestrus and periovulatory events in sheep exposed to 5 and 14 days of CIDR treatment with and without eCG.

The present study supports that 5-day short-term CIDR treatments without administration of eCG are equally effective for inducing oestrus behaviour, preovulatory LH discharge and ovulation in sheep than classical protocols based on 14-day treatments plus eCG at CIDR withdrawal. However, the implementation of a 5-day protocol without eCG for fixed-time artificial insemination would be adapted to a later timing of ovulation (p < .05).

Evaluation of different hormonal treatments on oestral and ovarian responses in Moroccan Beni Arouss goats during anoestrus and breeding season.

The efficacy of eight combinations of fluorogestone acetate (FGA, 20 or 40 mg as intravaginal device during 11 days), equine chorionic gonadotropin (eCG, 300 or 500 UI injected 48 hr before FGA removal) and prostaglandin F2α (cloprostenol, 0 or 50 µg injected 48 hr before FGA removal) aiming at induction and synchronization of oestrus and ovulation was evaluated during the anoestrus season in spring and during the breeding season in autumn in adult Beni Arouss goats. Oestrous behaviour was recorded between 12 and 60 hr after FGA removal. Blood samplings allowing to assess onset of the pre-ovulatory LH surge and increase of progesterone as sign of an active corpus luteum were performed, respectively, between 20 and 60 hr and 3, 5, 8 and 15 days after FGA removal. No season-related differences (spring vs. autumn) were observed for oestrous response (95% vs. 93%), pre-ovulatory LH surge (94% vs. 84%) and luteal response after 3-8 and 11-15 days post-treatment (respectively 92% vs. 66% and 92% vs. 98%). The onset of oestrus (21 [13-53] vs. 32 [12-54] hr) and LH surge (26 [20-60] vs. 38 [22-60] hr) occurred significantly later in autumn. FGA (40 vs. 20 mg) in autumn significantly delayed the onset of oestrus (36 [16-54] vs. 23 [12-47] hr) and LH surge (44 [26-58] vs. 33 [22-60] hr). Significant treatment-related differences were recorded for onset of LH surge (earliest for 20 mg FGA, 300 IU eCG, 50 µg PGF2α ) and onset of luteal phase (latest for 40 mg FGA, 300 IU eCG, 50 µg PGF2α ). In conclusion, the hormone combinations tested appeared equally effective in terms of oestrous and ovulation rates. Season has influenced significantly the onset of oestrus and LH surge, and the high dose regimen of FGA delayed the ovarian response in autumn.

Repeated pregnant mare serum gonadotropin-mediated oestrous synchronization alters gene expression in the ovaries and reduces reproductive performance in dairy goats.

This study aimed to elucidate the effects of repeated pregnant mare serum gonadotropin (PMSG) treatment for oestrous synchronization (ES) on ovarian gene expression and reproductive parameters in Xinong Saanen dairy goats, the dominant breed of dairy goat in China. The experiment was carried out at the Research Station of Northwest A&F University (NWAFU), China (34°16'N, 108°4'E). Forty-one does were randomly assigned to groups receiving ES treatments thrice every fortnight (3-PMSG group; n = 19), or ES treatment only once simultaneously with the third ES treatment in the 3-PMSG group (1-PMSG group; n = 22) during middle of the breeding season from late July (14 hr light) until late September (12 hr light). ES treatment was performed via intravaginal insertion of a controlled internal drug release (CIDR) device impregnated with 300 mg progesterone (P4), followed by 300 IU PMSG injections 48 hr before CIDR withdrawal. Oestrus was monitored using vasectomized bucks. Ovaries of three goats in oestrus from both groups were harvested for morphological examination and RNA sequencing (RNA-Seq). Then, all the oestrous goats in the 1-PMSG (n = 21) and 3-PMSG (n = 11) groups were artificially inseminated twice. The 3-PMSG group showed reduced oestrous rate (57.89%), pregnancy rate (31.58%) and litter size (1.17) compared, respectively, with 95.45%, 68.18% and 1.67 for 1-PMSG group (p < 0.05). However, no differences were found in the ovarian morphology between the 1-PMSG and 3-PMSG groups (p > 0.05). RNA-Seq revealed 114 differentially expressed genes (DEGs) in the ovaries of the 3-PMSG group, among which GCG, FSTL3, TET3 and AQP3 were deemed novel and promising candidate genes for regulating fertility. The present study indicates that the three-time PMSG treatment dysregulated several ovarian genes, thereby reducing reproductive performance.

Farmacopuntura utilizando os acupontos Hou Hai e Bai Hui em protocolos de sincronização de estro em cabras / Pharmacopuncture using acupoints Hou Hai and Bai Hui in estrous synchronization protocols in goats

Avaliou-se a eficiência da administração de subdoses de eCG nos acupontos Bai Hui e Hou Hai em protocolos de sincronização de estro em cabras. Na primeira etapa, 57 cabras foram distribuídas aleatoriamente em quatro tratamentos: T1- 300UI de eCG intramuscular (IM); T2- 60UI de eCG no acuponto Hou Hai; T3- 60UI de eCG no acuponto Bai Hui e T4- 60UI de eCG IM; e na segunda etapa, 28 cabras foram distribuídas aleatoriamente em três tratamentos: T1- 300UI de eCG IM; T2- 30UI de eCG no acuponto Bai Hui e T3- 30UI de eCG IM. Ao final do tratamento hormonal, as cabras foram monitoradas para detecção do estro, realização das coberturas e avaliação do comportamento reprodutivo. Os dados foram submetidos à análise de normalidade, seguida dos testes estatísticos adequados para cada variável. Na primeira etapa experimental, obteve-se maior duração de estro nas cabras do T1 (P=0,009). Na segunda etapa experimental, obteve-se maior número de animais em estros no T1 (P=0,03). As demais variáveis para ambas as etapas não sofreram influência dos tratamentos (P>0,05), demonstrando que a administração de subdoses de eCG nos acupontos Bai Hui e Hou Hai foi eficiente para sincronizar o estro.(AU)

The efficiency of administration of subdoses of eCG in the Bai Hui and Hou Hai acupoints in oestrus synchronization protocols in goats was evaluated. In the first stage, 57 goats were randomly assigned to four treatments: T1- 300UI of intramuscular eCG (IM); T2- 60UI of eCG in acupoint Hou Hai; T3- 60UI of eCG in the Bai Hui acupoint and T4- 60UI of eCG IM; and in the second stage, 28 goats were randomly assigned to three treatments: T1-300UI of eCG IM; T2-30UI of eCG in the Bai Hui acupoint and T3- 30UI of eCG IM. At the end of the hormonal treatment the goats were monitored for estrus detection, and evaluation of reproductive behavior. The data were submitted to normality analysis, followed by appropriate statistical tests for each variable. In the first experimental stage, a longer duration of estrus in the T1 goats (P= 0.009) was obtained. In the second experimental stage, a greater number of animals were obtained in estrus at T1 (P= 0.03). The other variables for both experiments were not influenced by the treatments (P> 0.05), demonstrating that administration of eCG subdoses in the Bai Hui and Hou Hai acupoints was efficient to synchronize the estrus.(AU)

What is the impact of short- and long-term supplementation of either cabergoline or clarithromycin on resolving rat ovarian hyperstimulation syndrome (OHSS) model?

This study aimed to evaluate the effects of coasting, cabergoline and clarithromycin in a rat ovarian hyperstimulation syndrome (OHSS) model. The 42 female Wistar rats were divided into seven groups: control, OHSS (was given 10 IU of pregnant mare serum gonadotropin for 4 consecutive days from day 22 and 30 IU hCG on the fifth day to induce OHSS ), coasting (hCG was applied on the 27th day after gonadotropin injections and the rats were decapitated on the 28th day), Cabergoline (100 mg/kg/d) and clarithromycin (100 mg/kg/d) were given (on the 26th day) with a short-term supplementation (on the 26th day) and long-term supplementation (from the 22nd to the 26th day) groups. The rats were decapitated on the 27th day. Cabergoline and clarithromycin significantly lowered VEGF-2 levels. Clarithromycin significantly reduced IL-1b and TNF-a and significantly increased IL-10 levels. Clarithromycin may be an effective drug for the treatment of OHSS. Impact statement What is already known on this subject? Ovarian hyper-stimulation syndrome (OHSS) is a self-limited disease, in which vascular endothelial growth factor (VEGF) plays the most important role and has a large clinical spectrum related with increased capillary permeability and fluid retention. Some treatment methods that block VEGF over-expression are used in treatment of OHSS. Clarithromycin is known to suppress the production of some pro-inflammatory molecules such as VEGF, IL-8, IL-1, IL-6 and TNF-a. In our study, we compared the efficacy of coasting, short- and long-term supplementation of clarithromycin and cabergoline on correcting OHSS parameters in an experimental study. What do the results of this study add? As a result of our study, we found that OHSS parameters improved better in early prophylactic treatment regimens. We have shown that clarithromycin may be a more effective treatment agent than coasting and cabergoline. What are the implications of these findings for clinical practice and/or further research? Although our study is important in that it is the first pilot study to show that clarithromycin is effective in the treatment of OHSS, there is a need for larger clinical trials.

Superovulatory response and embryo quality in Katahdin ewes treated with FSH or FSH plus eCG during non-breeding season.

The aim of this study was to evaluate the effect of a co-treatment of follicle-stimulating hormone (FSH) plus equine chorionic gonadotrophin (eCG) on serum insulin and insulin-like growth factor 1 (IGF-1) concentrations, superovulatory response, ovulatory rate, and number and production of embryos in Katahdin breed ewes during the non-breeding season. Twenty Katahdin ewes were synchronized with progestagens (CIDR) and assigned to two superovulation treatments (n = 10): (1): ewes treated with 200 mg ewe-1 of FSH from day 5 to 8 after CIDR insertion at decreasing doses every 12 h (FSH group) and (2) ewes treated as FSH group plus 300 IU of eCG on day 5 after CIDR insertion (FSH + eCG group). Estrous behavior was monitored and direct mating was performed. On days - 7 (CIDR insertion), 0 (CIDR withdrawal), and 7 (embryo recovery), blood samples were collected to determine serum hormone concentrations. Co-treatment with eCG (FSH group) did not affect (P > 0.05) serum hormone levels. Superovulation response, ovulation rate, recovery rate, fertilization, and number of embryos were also similar (P > 0.05) between treatments. Compared with FSH group, FSH + eCG ewes had lower (P < 0.05) number of transferable embryos and higher (P < 0.05) number of oocyte and a tendency to increase the number of degenerated embryos (P = 0.07). Overall results suggest that the administration of eCG is not beneficial either to improve the ovulatory response or the amount of transferable embryos in Katahdin ewes superovulated with a protocol using progesterone and FSH at decreasing doses.

Equine chorionic gonadotropin (eCG) enhances reproductive responses in CIDR-EB treated lactating anovular Nili-Ravi buffalo during the breeding season.

The objective of this study was to evaluate the effect of equine chorionic gonadotropin (eCG) on the estrous response, ovulatory follicle development, ovulation rate, corpus luteum (CL) diameter, concentrations of progesterone (P4) and pregnancy per AI (P/AI) in CIDR-EB treated lactating anovular Nili-Ravi buffalo during the breeding season. Buffalo (n = 87), 60 to 200 Days postpartum were treated with CIDR at a random stage of the estrous cycle (Day 0) and assigned to two groups; with eCG (+eCG; n = 44), or without eCG (-eCG; n = 43). In both groups, each animal received 2 and 1 mg estradiol benzoate (EB) on Day 0 and then on Day 8, respectively. On Day 6, eCG and PGF2α were administered. On Day 7, CIDR were removed and FTAI was performed at 48 and 60 h later and pregnancy was diagnosed 35 Days post AI. The results revealed that eCG treatment increased (P <  0.05) the CL diameter on 15, 18, and 21 after the ovulation that resulted from imposing the estrous synchronization protocol than when eCG was not administered. Similarly, treatment with eCG resulted in an increased (P <  0.05) mean concentration of P4 as compared with animals not treated with eCG on Days 18 and 21 after the ovulation that occurred subsequent to imposing the estrous synchronization protocol. The ovulation rate was greater in eCG-treated buffalo as compared with those not treated with eCG (93% compared with 74%, respectively; P < 0.05). The P/AI was greater in buffalo treated with eCG than those not treated with eCG (56% compared with 31%, respectively; P < 0.05). In conclusion, the addition of eCG along with EB and P4 based treatments enhanced the estrous response, follicular and luteal function, ovulation rate, concentrations of P4, and P/AI in lactating anovular Nili-Ravi buffalo.

Reproductive performance of Bos indicus beef cows treated with different doses of equine chorionic gonadotropin at the end of a progesterone-estrogen based protocol for fixed-time artificial insemination.

Two experiments were performed to evaluate the reproductive performance of zebu beef cows treated with different doses of eCG at the end of a progesterone (P4)/estrogen based protocol for timed artificial insemination (TAI). In Experiment 1, suckling Bos indicus Nelore cows (n = 261) received, on day 0, a progesterone (P4) intravaginal device (PD) and an injection of 1 mg estradiol benzoate (EB). On day 8, the PD was removed, 500 µg of cloprostenol was injected, and cows were assigned to one of the following groups: Control (no treatment), 300 (300 IU of eCG), 600 (600 IU of eCG), and 900 (900 IU of eCG). On day 9, all cows received 1 mg EB and TAI performed 54-56 h after cloprostenol injection. A pregnancy diagnosis was done by ultrasound scanning 40 days after TAI, and the number of fetuses and calves was recorded at pregnancy diagnosis and at birth. More cows treated with eCG displayed estrus within 48 h after removal of the PD (42.3% vs. 11.6%, P < 0.01), and ovulated more than one follicle (42%, 58/138 vs. 1.8%, 1/54; P < 0.01). This effect on ovulation rate was dose dependent (P < 0.05). The pregnancy rate was affected only by cow parity (primiparous, 25.3% vs. multiparous, 48.9%; P < 0.01). Twin pregnancy was higher (P < 0.01) in cows treated with eCG (42%, 58/138) than controls (0%, 0/54). However, few cows (33.3%) were able to keep both fetuses intact until birth. For evaluation of ovarian characteristics by B-mode and Doppler ultrasonography, 43 Nelore cows were submitted In Experiment 2 to the same four groups described in Experiment 1. Although no difference (P > 0.1) was observed for size and blood perfusion in the pre-ovulatory follicles, corpus luteum was larger and with greater blood perfusion (P < 0.05) in eCG-treated cows. In conclusion, eCG increased the number of double/multiple ovulations in a dose-dependent manner, induced larger and more vascularized corpora lutea, but did not affect the fertility of cyclic or anestrous cows. Although eCG results in twin pregnancies, most of cows underwet embryo/fetus loss and birth a single calf.

The effects of resveratrol on ovarian hyperstimulation syndrome in a rat model.

OBJECTIVE: The aim of the present study was to investigate effects of resveratrol (RSV) over ovarian hyperstimulation syndrome (OHSS) in rat model. MATERIALS AND METHODS: 24 female Wistar rats (22 days old) were divided into four groups. Group 1 (control group; n = 6) received 0.1 ml intraperitoneal (IP) saline from days 22-26; group 2 (mild-stimulated group; n = 6) received 10 IU pregnant mare serum gonadotropin (PMSG) on day 24 and 10 IU of hCG 48 h later (day 26); group 3 (OHSS group; n = 6) was given 10 IU of PMSG for 4 consecutive days from day 22 and 30 IU hCG on the fifth day to induce OHSS; group 4 (OHSS + RSV group; n = 6) was treated the same as group 3, but received 60 mg/kg RSV 2 h before PMSG injection for 4 consecutive days and 2 h before the hCG injection on the fifth day. RESULTS: Weight gain was highest in the OHSS group. Ovarian weights were lower in the treatment group than OHSS group. Peritoneal fluid VEGF levels were lower for RSV group compared to group 2 and 3. Total VEGF immunoreactivity was higher in OHSS group than group 1, 2 and 4. CONCLUSION: These results indicate that RSV is beneficial for prevention of OHSS by reducing the increases in body and ovarian weight and VEGF activity. These effects may be mediated by anti-inflammatory, anti-oxidant and anti-angiogenic capacity of RSV.

Effect of consecutive re-synchronization protocols on pregnancy rate in buffalo (Bubalus bubalis) heifers out of the breeding season.

The combined effect of six consecutive timed artificial inseminations (TAIs) on pregnancy rates, following two different synchronization protocols on buffalo heifers, over a period of seven months typically characterized by low breeding performances, were investigated in this study. A total of 2189 TAIs were performed on 1463 buffalo heifers within a large buffalo farm in the south of Italy. Individual animals were allowed to undergo synchronization protocol (either a slightly modified Ovsynch or Progesterone treatment) and TAI until establishment of pregnancy or else for not more than six consecutive times. Semen of seven proven bulls was used throughout the study, which was carried out from March to September of the same year. Therefore, other than the effect given by consecutive TAIs over time, a monthly and a seasonal effect could also be tested, once the entire period was split into a Low Breeding Season (LBS) from March to June, and a Transition to Breeding Season (TBS) from July to September. From the data recorded in this study and the statistical analysis performed, it can be stated that the two protocols for the synchronization of ovulation were similar in efficiency in determining pregnancies with an overall fertility rate of 89.4% when the comparison was run both on a monthly basis or when months were grouped into two different seasons. In addition, an average of 1.83 AI/pregnancy was reported, slightly higher for the Ovsynch when compared to the Progesterone protocol: 1.91 vs 1.70, respectively. Finally, when considering the number of progressive synchronization treatments implemented over time as covariate, neither Ovsynch nor Progesterone treatment significantly affected pregnancy rates following the first of the six synchronization sessions. However, repeating the synchronization procedure, the progesterone based protocol resulted in significantly higher probability of success in terms of established pregnancies during the second and third re-synchronization sessions.

Effectiveness of controlled internal drug release device treatment to alleviate reproductive seasonality in anestrus lactating or dry Barki and Rahmani ewes during non-breeding season.

This study aimed to evaluate the effectiveness of hormonal treatments on ovarian activity and reproductive performance in Barki and Rahmani ewes during non-breeding season. Forty-eight multiparous ewes, 24 Barki and 24 Rahmani ewes were divided into two groups, 12 lactating and 12 dry ewes for each breed. Controlled internal drug release (CIDR) device was inserted in all ewes for 14 days in conjunction with intramuscular 500 IU equine chronic gonadotrophin (eCG) at day of CIDR removal. Data were analysed using PROC MIXED of SAS for repeated measures. Breed, physiological status and days were used as fixed effects and individual ewes as random effects. Barki ewes recorded higher (p < .05) total number of follicles, number of large follicles, serum estradiol concentration and estradiol: progesterone (E2 :P4 ) ratio compared to Rahmani ewes. Lactating ewes recorded higher (p < .05) number of small follicles and lower concentration of total antioxidant capacity (TAC) compared to dry ewes. Number and diameter of large follicles recorded the highest (p < .05) values accompanied with disappearance of corpora lutea at day of mating. Serum progesterone concentration recorded lower (p < .05) value at day of mating and the highest (p < .05) value at day 35 after mating. CIDR-eCG protocol induced 100% oestrous behaviour in both breeds, but Rahmani ewes recorded longer (p < .05) oestrous duration compared to Barki. Conception failure was higher (p < .05) in Barki compared to Rahmani ewes. In conclusion, CIDR-eCG protocol was more potent in improving ovarian activity in Barki compared to Rahmani ewes, but this protocol seems to induce hormonal imbalance in Barki ewes that resulted in increasing conception failure compared to Rahmani ewes.

Progesterone-releasing devices for cattle estrus induction and synchronization: Device optimization to anticipate shorter treatment durations and new device developments.

Synchronization programs using progesterone-releasing intravaginal devices that allow for fixed time artificial insemination are still finding increasing application in bovine reproduction. This practice is useful for rationalizing livestock management because an increased number of cows can be inseminated in one session without the need for estrus detection. Although much of the innovation related to the design and development of intravaginal devices for use in cattle took place in the previous century, progress in understanding the physiology of the bovine estrous cycle resulted in shorter treatment durations, a trend which is still continuing. In this competitive market, with little functional differentiation between the existing devices, the shorter treatment duration prompted for optimization of the progesterone content in the device, as the cost of the drug significantly contributes to the price per unit. For CIDR® a reduction of the progesterone content of about 30 per cent was realized. Price reduction remained an important target for further device development. Next to reduction of progesterone content, cheaper and easier to process materials like polyethylene vinyl acetate (EVA) copolymers have been explored to replace the commonly used silicone elastomers. The reengineering effort of CIDR® demonstrated that knowledge of release kinetics and insight into gradual depletion patterns in the device is critical for optimization of drug content without compromising performance (blood levels). More recent publications related to the use of alternative polymers like EVA and polyisoprene (IP) indicated encouraging results regarding further reduction of progesterone content. The use of EVA seems most promising, because it is in principle a low-cost polymer available in many grades and this thermoplastic polymer can be processed easily by means of commonly used techniques like injection molding and extrusion. The use of thermoplastic polymers, however, requires insight into the physical-chemical phenomena related to drug dissolution and re-crystallization taking place in the polymer during processing at high temperatures. These aspects, which may critically affect product stability, are often overlooked and are prompting to cover some of the background in this review. Finally, two different innovative approaches are discussed, one related to programable electronic devices for tailored simultaneous drug release and the other is a flexible drug-loaded helix, which is retained very well in several species without causing the usual inflammatory response.