Effect of royal jelly and GnRH on the estrus synchronization and pregnancy rate in ewes using intravaginal sponges

Effects of royal jelly on ovary cancer cells proliferation and apoptosis

The aim of the present study is to investigate the proliferative or apoptotic effects of different doses and durations of Royal jelly (RJ) on serous type epithelial ovarian cancer, which is the most common epithelial ovarian cancer. For this purpose, cells of the Skov-3 human ovarian adenocarcinoma cell line were grown in McCoy medium and seeded in 6-well plates. RJ was prepared as a stock solution (1000 mg RJ/10 ml dH2O) and 1, 5, 10, 20, and 50 mg/ml RJ doses from the prepared stock solution were added to the medium for 24, 48, and 72 h incubated. After the treatment of RJ, the cell viability test (Tripan Blue), Ki-67 to determine the proliferative effect, cleaved-Caspase-3 and cleaved PARP expressions to determine its apoptotic effect were examined by immunocytochemical and immunofluorescence methods. In addition, findings were supported by the TUNEL method. As a result of the experiments, it was determined that 1 mg/ml and 24 h treatment of RJ did not affect cell proliferation and apoptosis, but generally, 50 mg/ml of RJ for 72 h inhibited proliferation in cancer cells and induced apoptosis. The use of royal jelly both monotherapeutically and in combination as an alternative treatment for ovarian cancer may provide the basis for new experimental protocols.

Royal jelly and its hormonal effects in breast cancer: a literature review

BACKGROUND

Breast cancer is the most common cancer in women which can be cured in most individuals with early-stage non-metastatic disease. Imbalance in estrogen signaling pathways and propagating levels of estrogens has important roles in breast cancer development. Targeting the estrogen receptor signaling pathway is linked to breast cancer treatment. Royal jelly is one of the bee products containing 10-hydroxy-2-decenoic acid, a structure similar to mammalian estrogen, allowing it to attach to estrogen receptors. It is considered as a general tonic and immunomodulator which may be helpful in reducing the side effects of cancer treatments. Currently, there are controversial data regarding the pros and cons of royal jelly in cancer. Here we provide an overview of the effects of royal jelly on sex hormones and its possible role in breast cancer.

METHODS

Electronic databases including PubMed, Scopus, and Web of Science were searched with the search terms royal jelly, cancer, and sexual hormones. All preclinical and clinical studies regarding the hormonal effects of royal jelly were included.

RESULTS

According to the collected preclinical data, consumption of royal jelly at daily doses below 200 mg/kg can be useful to decrease the risk of breast cancer since it reduces the serum level of estrogen; whereas increases progesterone, which subsequently decreases the expression of ERs on the ER-positive cells.

CONCLUSION

Future clinical studies are essential to confirm the safe dose of royal jelly as an adjuvant therapy in breast cancer.

Exploring Endogenous and Exogenous Factors for Successful Artificial Insemination in Sheep: A Global Overview

Artificial insemination (AI) plays a vital role in animal breeding programs. AI is applied to enhance animal genetics and facilitate the widespread integration of desirable characteristics with a high potential for productivity. However, in sheep, this biotechnology is not commonly practicable due to multi-factorial challenges, resulting in inconsistent outcomes and unpredictable results. Thoughtful selection of semen donors and recipients based on genetic merit deeply impacts ovine AI outcomes. Additionally, endogenous factors such as breed, age, fertility traits, genetic disorders, and cervical anatomy in ewes contribute to ovine AI success. Extensive research has studied exogenous influences on sexual behavior, reproductive health, and hormonal regulation, all impacting ovine AI success. These exogenous factors include techniques like estrus induction, synchronization, semen handling methods (fresh/chilled/frozen), and insemination methods (cervical/laparoscopic), as well as nutritional factors and climatic conditions. This overview of the literature highlights the endogenous and exogenous challenges facing successful ovine AI and proposes strategies and best practices for improvement. This paper will serve as a guide for understanding and optimizing the success of ovine AI.

Effect of Nutritional Flushing Using Long-Term Energy and Protein Supplementation on Growth Performance and Reproductive Parameters of Doyogena Ewes in Ethiopia

The objective of the study was to establish the effect of appropriate supplementation days (days -21 to +7) using four isonitrogenous (14.7% CP) diets balanced to provide low (Lo-ME) or high (Hi-ME) metabolizable energy on the body condition score (BCS), body weight (BW) change, and reproductive performances of sheep. Thirty-five Doyogena ewes (27.71 ± 2.87 kg, 2-5 years of age, BCS of 2.0-2.5) grazing on natural pasture were randomly assigned to supplementary treatments consisting of combinations of enset leaf (EL) and commercial concentrate (CC): T0 (control), T1 (250 g EL + 500 g CC: Lo-ME), T2 (400 g EL + 500 g CC; Hi-ME), T3 (500 g EL + 400 g CC; Hi-ME), and T4 (500 g EL + 250 g CC; Lo-ME). The estrous cycle was synchronized with one intramuscular injection, 5 mg PGF2α, prior to artificial insemination. The dry matter (DM) from the pasture provided 1.10-1.46 kg/day, which corresponds to the DM requirements of the ewes until late gestation. However, the pasture provided a protein content of 9.52%, which was insufficient for breeding, mid-gestation, and gestation, requiring minimums of 16.1%, 13.1%, and 14.8%, respectively. The pasture could only provide enough energy for breeding ewes with a BW of up to 30 kg. The energy provided by pasture was insufficient for ewes weighing > 30 kg at mid-gestation and gestation, providing 6.9-9.2 MJ/day, below the requirement of 11.92-16.32 MJ/day required for mid-gestation and gestation. The energy was not sufficient for large ewes weighing > 40 kg. Supplementary diets T1-T4 provided DM in the range of 1.7-2.29 kg/day. This was sufficient for AI, mid-gestation, and gestation phases. Dietary supplements increased (p < 0.01) BW during breeding and mid-gestation. During lambing, T2 and T3 increased BW (p < 0.05) compared to T4 and T1. T4 had a similar effect (p > 0.05) on BW during lambing. T1, T2, and T3 significantly increased BCS (p < 0.05). T2 and T3 increased (p < 0.05) BCS at mid-gestation, but only T2 significantly increased BCD (p < 0.05) during lambing. All dietary supplements resulted in a shorter (p < 0.05) time to the resumption of estrous and the length of estrous (p < 0.05). T1, T2, and T3 resulted in a stronger estrous response (p < 0.05). Dietary supplements enhanced (p < 0.05) the conception rate and fecundity rate. The conception rate was highest in T2 and T3 at 85.7% and 83.3%, respectively. T2 had the highest fecundity rate at 151.7% (p < 0.05). Dietary supplementation increased the rate of lambing (LR), litter size (LS), and weight of lambs at birth (LBW). The LR for treatments T2, T3, and T4 was 100% versus 66.7% in the control. T1 and T2 significantly increased (p < 0.05) LS, but T4 had a similar LS to the control. Dietary supplements T1, T3, and T4 tended to increase (p < 0.05) LBW, but T2 increased LBW significantly (p < 0.05). Supplementation (T2, T3) with 400 g enset + 500 g CC and 500 g enset + 400 g CC are promising feed supplements to increase the reproductive capacities of Doyogena ewes in Ethiopia. Energy is as important to ewe flushing as protein.

UPLC-MS/MS Analysis of Naturally Derived Apis mellifera Products and Their Promising Effects against Cadmium-Induced Adverse Effects in Female Rats

Honeybee products arouse interest in society due to their natural origin and range of important biological properties. Propolis (P) and royal jelly (RJ) attract scientists' attention because they exhibit antioxidant, anti-inflammatory, anti-bacterial, anti-tumor, and immunomodulatory abilities. In this study, we tested whether P and RJ could mitigate the adverse effects of cadmium (Cd) exposure, with particular emphasis on the reproductive function in female rats. In this line, one week of pretreatment was established. Six experimental groups were created, including (i) the control group (without any supplementation), (ii) the Cd group (receiving CdCl₂ in a dose of 4.5 mg/kg/day), (iii) the P group (50 mg of P/kg/day), (iv) RJ group (200 mg of RJ/kg/day), (v) P + Cd group (rats pretreated with P and then treated with P and Cd simultaneously), (vi) RJ + Cd group (animals pretreated with RJ before receiving CdCl₂ simultaneously with RJ). Cd treatment of rats adversely affected a number of measured parameters, including body weight, ovarian structure and ultrastructure, oxidative stress parameters, increased ovarian Cd content and prolonged the estrous cycle. Pretreatment and then cotreatment with P or RJ and Cd alleviated the adverse effects of Cd, transferring the clusters in the PCA analysis chart toward the control group. However, clusters for cotreated groups were still distinctly separated from the control and P, or RJ alone treated groups. Most likely, investigated honeybee products can alter Cd absorption in the gut and/or increase its excretion through the kidneys and/or mitigate oxidative stress by various components. Undoubtedly, pretreatment with P or RJ can effectively prepare the organism to overcome harmful insults. Although the chemical composition of RJ and P is relatively well known, focusing on proportion, duration, and scheme of treatment, as well as the effects of particular components, may provide interesting data in the future. In the era of returning to natural products, both P and RJ seem valuable materials for further consideration as anti-infertility agents.

The pharmacokinetics of letrozole and its effect on gonadotropins in anestrous ewes

The aim of this study was to determine the pharmacokinetics of letrozole and its effect on FSH and LH concentrations after single (IV, IM, SC) and repeated IV doses in anestrous ewes. This study was conducted in experiments 1 and 2 by randomly dividing 24 healthy Akkaraman ewes in anestrus into two equal groups. In experiment 1, the pharmacokinetics of letrozole following single IV, IM, and SC administration at 1 mg/kg dose and its effect of a single IV dose on plasma FSH and LH concentration were determined. In experiment 2, the effect of repeated IV doses of letrozole on FSH and LH concentrations was established. Plasma concentration of letrozole was measured using high-performance liquid chromatography, and pharmacokinetic parameters were calculated by non-compartmental analysis. FSH and LH concentrations were quantified using ELISA. The elimination half-life (t_1/2ʎz) for IV, IM, and SC routes were 9.94, 37.29, and 41.07 h, respectively. The IV route for letrozole had a total clearance of 0.11 L/h/kg and a volume of distribution at a steady state of 1.50 L/kg. The peak plasma concentration was 0.11 μg/mL for the IM route and 0.14 μg/mL for the SC routes. The bioavailability was 55.18% for the IM route and 75.34% for the SC route. Letrozole following single and repeated (every 24 h for 3 days) IV administrations at 1 mg/kg dose did not affect LH concentration in anestrous ewes but caused an increase in the FSH concentration. This increase in FSH concentration may create a potential for the use of letrozole in ovarian superstimulation protocols. Favorable pharmacokinetic properties (long t_1/2ʎz and good bioavailability) of letrozole for IM and SC routes require further investigation before use in estrus induction or estrus synchronization protocols in sheep.

Synergistic effect of royal jelly in combination with glycerol and dimethyl sulfoxide on cryoprotection of Romanov ram sperm

Sperm fertility decreases significantly after freezing. Providing a suitable and useful diluent compound for freezing ram sperm can increase the efficiency of artificial insemination and consequently, the reproductive performance of sheep. Various biological properties such as antibacterial, anti-cancer, immunosuppressive, antioxidant and reproductive properties of royal jelly (RJ) are well known. The aim of this study was to investigate the possible synergistic effect of royal jelly in combination with glycerol and dimethyl sulfoxide (DMSO) in sperm cryopreservation extender of Romanov ram. The pooled semen samples from 5 Romanov rams were allocated into 3 experiments. The effect of 6% DMSO, 6% glycerol and a combination of 3% DMSO +3% glycerol co-supplemented with 1, 2 and 3% RJ was evaluated in 3 experiments. Samples were frozen by conventional slow freezing method and post-thaw parameters of total motility, progressive motility, plasma membrane integrity, DNA damage, apoptosis, enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx), total antioxidant capacity (TAC) and malondialdehyde (MDA) were evaluated. The results showed that the percentage of motility, progressive motility, TAC, GPx, SOD and all sperm kinematic parameters except LIN in the group containing 2% RJ + 6% DMSO was higher than the control group (p < 0.05). Some parameters such as progressive motility, sperm membrane integrity, TAC, GPx, VAP, VCL, STR and SRT in the group containing 2% RJ + 6% DMSO were more than (p < 0.05) in the sperm group containing 1% RJ + 6% DMSO. MDA values in sperm groups containing 2% RJ + 6% DMSO were significantly (p < 0.05) lower than the sperm containing 1% royal jelly and the control group. In the sperm group containing 2% RJ + 6% glycerol, sperm membrane integrity, TAC, GPx, SOD, progressive motility and all sperm kinematic parameters except VAP were higher and MDA values and sperm abnormalities were lower than the control group (p < 0.05). The sperm group containing 1% RJ and 3% DMSO +3% glycerol had higher motility, progressive motility, membrane integrity, and all sperm kinematic parameters except VSL; and lower sperm abnormalities, DNA damage, apoptosis and MDA than the control group (p < 0.05). As a general conclusion of this study, the addition of 2% RJ + 3% DMSO and 3% glycerol to the freezing extender improved microscopic and biochemical ram sperm parameters after the freeze-thaw process. Hence, moderate concentrations of royal jelly (2%) are sufficient to protect sperm from freezing damage, and high (3%) and low (1%) concentrations do not have a good cryoprotective effect.

Improving Reproductive Performance and Health of Mammals Using Honeybee Products

Honeybee products have positive effects on the reproductive performance of mammals. Many honeybee product constituents are biologically active, with antioxidant, antimicrobial, antiviral, anti-inflammatory, immunomodulatory, antifungal, wound-healing, and cardio-protective properties. Honeybee products also improve male and female fertility rates by enhancing gamete cryopreservation, in vitro maturation and fertilization, and embryo development. Previously published studies confirmed their efficacy for alleviating reproductive toxicity caused by contaminants and lifestyle habits that impair overall health and well-being. However, high-dose oral administration of honeybee products may adversely affect the reproductive system, and unfavorable effects were alleviated by treatment cessation. For this reason, this review proposes that bioactive components from bee products can be used as a strategy for improving the reproductive performance and health of mammals.

Composition of Royal Jelly (RJ) and Its Anti-Androgenic Effect on Reproductive Parameters in a Polycystic Ovarian Syndrome (PCOS) Animal Model

Royal jelly (RJ) has been shown to contribute its positive effects upon imbalance in the reproductive system. However, it remains unknown as to whether RJ has an anti-androgenic effect on reproductive parameters in a polycystic ovarian syndrome (PCOS) animal model. Composition of RJ was assessed by phytochemical screening and the LC–MS method. Forty immature female rats (3 weeks, 40–50 g) were randomly divided into five groups (n = 8 per group), i.e., control, testosterone (T), T+100RJ (100 mg/kg/day), T+200RJ (200 mg/kg/day RJ), and T+400RJ (400 mg/kg/day RJ) groups. Hyperandrogenism was induced by daily subcutaneous injection of T propionate for 3 weeks, followed by oral RJ for 4 weeks. The T+200RJ group had a significantly higher follicle-stimulating hormone level, and significantly lower luteinizing hormone, testosterone, and estradiol levels in comparison to the T group. Malondialdehyde level and glutathione peroxidase activity were significantly lower, while total antioxidant capacity level was significantly higher in the T+200RJ group compared to the T group. Histologically, the T+200RJ group showed recovery of various stages of ovarian follicular development. RJ at 200 mg/kg/day for 4 weeks significantly improved reproductive parameters in PCOS rats partly due to its anti-androgenic effect through antioxidant action and probably due to modulation on estrogenic activity, which needs further study to evaluate its exact mechanism of action.

Royal jelly may improve the metabolism of glucose and redox state of ovine oocytes matured in vitro and embryonic development following in vitro fertilization

The aim of this study was to investigate the effect of different concentrations of royal jelly (RJ) on in vitro maturation (IVM), fertilization, cleavage, blastocyst rates, glutathione (GSH) content in ovine oocyte, mRNA abundance of antioxidant enzymes in both oocyte and cumulus, and glucose metabolism-related genes in cumulus cells. In vitro maturation of oocyte was performed in the presence of control (RJ₀), 2.5 (RJ_2.5), 5 (RJ₅), and 10 (RJ₁₀) mg/mL of RJ. Nuclear status, intracellular GSH content in oocytes, and mRNA abundance of selected genes were evaluated following 24 hours of IVM. Following the IVM, fertilization and embryo culture were carried out in all the groups and embryonic development was examined. The addition of 10-mg/mL RJ to maturation media not only yielded a higher number of oocytes at MII stage but also showed an increased level of intracellular GSH content than did RJ_2.5 and control groups. Fertilization, cleavage, and blastocyst rate were higher in the RJ₁₀ treatment group in comparison to the control one. In cumulus cells, the expression of PFKM, PFKL, and G6PDH were increased following the addition of RJ to the maturation media. Supplementation of 10-mg/mL RJ to IVM medium increased the GPx mRNA abundance in both oocyte and cumulus cells and SOD expression in the cumulus cells. The CAT mRNA abundance was not influenced by the addition of RJ to the maturation media in either oocyte or cumulus cells. It seems that the improvement of oocyte maturation and its subsequent development in RJ₁₀ group may be associated with amelioration of redox status in the oocytes and activation of glucose metabolic pathways in their surrounding cumulus cells.

Microscopia e morfometria de componentes tubulares de testículos de coelhos suplementados com geleia real

Estudaram-se os efeitos da geleia real sobre a espermatogênese de coelhos tratados com diferentes concentrações de geleia real. Os tratamentos foram formados por três grupos: grupo-controle; grupo que recebeu 0,5mg/dia de geleia real; e grupo que recebeu 1,0mg/dia de geleia real. O estudo envolveu a morfometria testicular. Não houve diferença entre os tratamentos quanto aos pesos corporal (T1=3,20±0,19kg, T2=2,96±0,30kg e T3=3,21±0,37kg) e gonadal (T1=2,36±0,33g, T2=2,53±0,33g e T3=2,64±0,39g) e quanto aos índices gonadossomático (T1=0,15±0,02%, T2=0,17±0,03% e T3=0,16±0,02%) e tubulossomático (T1=0,06±0,01%; T2=0,07±0,01% e T3=0,06±0,01%). O diâmetro médio dos túbulos seminíferos (T1=225,95±13,27µm, T2=239,68±21,50µm e T3=231,57±15,94µm), a altura do epitélio seminífero (T1=66,05±5,37µm, T2= 73,47±9,11µm e T3=63,34±4,79µm) e o comprimento de túbulos seminíferos por testículo (T1=46,63±13,44m, T2=43,58±12,17m e T3=46,96±9,54m) e por grama de testículo (T1=19,50±2,68m, T2=17,12±3,91m e T3=17,78±1,98m) não diferiram entre tratamentos. Conclui-se que a suplementação com geleia real, nas doses utilizadas, não altera as características testiculares avaliadas.

Fatty acids derived from royal jelly are modulators of estrogen receptor functions

Royal jelly (RJ) excreted by honeybees and used as a nutritional and medicinal agent has estrogen-like effects, yet the compounds mediating these effects remain unidentified. The possible effects of three RJ fatty acids (FAs) (10-hydroxy-2-decenoic-10H2DA, 3,10-dihydroxydecanoic-3,10DDA, sebacic acid-SA) on estrogen signaling was investigated in various cellular systems. In MCF-7 cells, FAs, in absence of estradiol (E₂), modulated the estrogen receptor (ER) recruitment to the pS2 promoter and pS2 mRNA levels via only ERβ but not ERα, while in presence of E₂ FAs modulated both ERβ and ERα. Moreover, in presence of FAs, the E₂-induced recruitment of the EAB1 co-activator peptide to ERα is masked and the E₂-induced estrogen response element (ERE)-mediated transactivation is inhibited. In HeLa cells, in absence of E₂, FAs inhibited the ERE-mediated transactivation by ERβ but not ERα, while in presence of E₂, FAs inhibited ERE-activity by both ERβ and ERα. Molecular modeling revealed favorable binding of FAs to ERα at the co-activator-binding site, while binding assays showed that FAs did not bind to the ligand-binding pocket of ERα or ERβ. In KS483 osteoblasts, FAs, like E₂, induced mineralization via an ER-dependent way. Our data propose a possible molecular mechanism for the estrogenic activities of RJ's components which, although structurally entirely different from E₂, mediate estrogen signaling, at least in part, by modulating the recruitment of ERα, ERβ and co-activators to target genes.

Parâmetros morfofisiológicos testiculares de camundongos (Mus musculus) suplementados com geleia real

Avaliaram-se os efeitos da geleia real sobre os parâmetros morfofisiológicos testiculares de camundongos (Mus musculus). Utilizaram-se 57 machos Swiss, com quatro meses de idade, distribuídos aleatoriamente em seis tratamentos: T1: solução fisiológica, via intraperitoneal; T2: 0,1mg de geleia real, via intraperitoneal; T3: 0,2mg de geleia real, via intraperitoneal; T4: água destilada, via oral; T5: 0,1mg de geleia real, via oral; e T6: 0,2mg de geleia real, via oral. Após 45 dias de suplementação com geleia real, os animais sacrificados e pesados tiveram seus testículos coletados, incluídos em parafina e corados com hematoxilina/eosina. Não houve diferença entre os tratamentos quanto aos: pesos corporal e testicular, índice gonadossomático, diâmetro tubular, altura do epitélio, comprimento total dos túbulos seminíferos, comprimento tubular por grama de testículo, índices tubulossomático e leydigossomático e valores de proporção volumétrica referentes à túnica própria, epitélio seminífero, vaso sanguíneo e vaso linfático. Foi encontrada diferença entre T1 e T3 em relação aos túbulos seminíferos e ao espaço intertubular.

Synchrony of ovulation and follicular dynamics in merino ewes treated with GnRH in the breeding and non-breeding seasons

The effect of gonadotropin releasing hormone (GnRH) treatment on the time of ovulation and the occurrence of follicular dominance during the non-breeding and breeding seasons (experiment 1), and on fertility after artificial insemination (AI) in the non-breeding season (experiment 2), was examined in Merino ewes. Oestrus was synchronized in 40 nulliparous ewes (experiment 1; n = 20, in the non-breeding and breeding seasons) and in 79 multiparous ewes (experiment 2) using intravaginal sponges and pregnant mare serum gonadotropin. Thirty six hours after sponge removal (SR), half the ewes were injected (i.m.) with 40 microg of synthetic GnRH and the remainder used as controls. GnRH improved the synchrony of ovulation compared with the controls in the breeding (SD = 2.8 vs 5.7 days, p = 0.04) but not the non-breeding season (SD = 3.8 vs 4.4 days, p = 0.69), with ewes ovulating from 42 to 54 h (mean 50.4 +/- 4.08 h) and 42-60 h (mean 54.4 +/- 5.47 h) after SR for GnRH and control, respectively. For both treated and control ewes, ovulation occurred earlier in the non-breeding than the breeding season (50.1 vs 54.6 h; p = 0.002). GnRH had no effect on follicular dominance, as assessed by divergence (D: the time the ovulatory follicle exceeded the average size of the other non-ovulating follicles) or on the interval from D to ovulation (IDO). However, follicular dynamics differed between seasons. The mean follicle diameter increased at a faster rate up to 36 h after SR in the non-breeding compared with the breeding season and then rapidly declined, compared with a later peak (42 h after SR) in mean follicular size during the breeding season. IDO was shorter in the non-breeding than in the breeding season (26.7 +/- 4.30 h vs 39.6 +/- 4.53 h; p = 0.05). In experiment 2, ewes (n = 38 GnRH-treated, n = 40 controls) were inseminated in the uterus by laparoscopy 42 h or 48 h after SR with frozen-thawed sperm. The fertility of ewes treated with GnRH (nine of 39, 23%) was not different to the controls (eight of 38, 21%; p = 0.01). In conclusion the application of GnRH improved synchronization of ovulation but did not improve fertility rates after AI.

A new approach to enhance reproductive performance in sheep using royal jelly in comparison with equine chorionic gonadotropin

The objective was to compare the effects of royal jelly (RJ) and eCG treatments on reproductive performance of ewes synchronized using intravaginal progesterone-releasing devices. Forty-two cycling Awassi ewes were treated intramuscularly (i.m.) with 15 mg PGF2alpha. On the following day, all ewes were administered with CIDR-G for 12 days and were randomly allocated to three (RJ, eCG and control) groups of 14 ewes each. Ewes in the RJ-treated group received daily i.m. treatments of 400mg RJ during the period of CIDR-treatment. Each ewe in the eCG-treated group received an i.m. treatment of 500 IU eCG at the time of CIDR-G removal (day 0) and no further treatment was given to ewes in the control group. Ewes were exposed to four fertile rams for 72 h, from the time of CIDR-G removal, and checked for breeding marks at 6-h intervals. Blood samples were collected from day -13 until day 0 and thereafter until day 19 for progesterone analysis. Royal jelly treatment resulted in a greater rate of decline and lower (P<0.02) progesterone concentrations between days -10 and 0 than eCG-treated and control ewes. Expression of estrus was similar among the three groups and intervals to onset of estrus were shorter (P<0.01) in RJ-treated (31.3h) and eCG-treated (29.8h) than control (41.3h) ewes. First-cycle pregnancy and lambing rates were greater (P<0.05) in RJ-treated (71.4 and 71.4%) and eCG-treated (85.7 and 78.6%) than in control (42.9 and 35.7%) ewes, respectively. Results demonstrate that the treatments of RJ and eCG in conjunction with CIDR-G were similarly effective in induction of estrus and improvement of pregnancy and lambing rates.

Reproductive responses in ewes treated with eCG or increasing doses of royal jelly

This experiment was conducted to evaluate the effect of administering increasing doses of royal jelly (RJ) on reproductive parameters in ewes. Additionally, this study compared using RJ vs. equine chorionic gonadotropin (eCG) in estrous cycle control. In May (transitional period between anestrous and the breeding season) 37 multiparous, winter-lambing Awassi ewes 3-6 years of age (average body weight of 53+/-1.2 kg) were fitted with intravaginal flourogestone acetate-impregnated sponges (FGA, 40 mg) for 12 days. Ewes were randomly assigned into five treatment groups to receive no RJ (CON, n=7), 250 mg RJ/d (RJ250, n=8), 500 mg RJ/d (RJ500, n=8), 750 mg RJ/d (RJ750, n=7), or 600IU eCG (eCG, n=7). Royal jelly was administrated orally on daily basis when sponges were in place while eCG was administered on the day of sponge withdrawal (d 0). Behavioral estrus was checked using fertile Awassi rams at 6h intervals for 5 days beginning on d 1. Interval from d 0 to onset of estrus was shorter (P<0.05) in eCG than in CON and RJ250 groups. No differences in the onset of estrus were detected among the RJ-treated groups. The intervals from d 0 to first progesterone rise were shorter (P<0.05) in the eCG-treated compared with RJ-treated and control ewes (100+/-15.3, 138.4+/-14, 135.7+/-15, 155.6+/-15, 154.4+/-15.1h in eCG, CON, RJ250, RJ500, and RJ750, groups, respectively). The overall pregnancy rate from mating at induced estrus was 75.7% (28/37). Of these ewes, 23/37 (64.8%) lambed within 155 days following d 0. Lambing rate was higher (P<0.05) in the RJ500 group compared with controls. Lambing rate from mating at induced estrus was 2/7 (28.5%), 4/8 (50%), 8/8 (100%), 4/7 (57%), and 5/7 (71%) in CON, RJ250, RJ500, RJ750, and eCG groups, respectively. Results of the present study demonstrate that eCG but not RJ was effective in improving estrus expression in ewes during the transition between the non-breeding and breeding seasons. Royal jelly may be effective in improving pregnancy and lambing rates but further studies are required to confirm such findings.