Buserelin Research Articles

Daily administration of a GnRH analogue enhances sperm quality in bucks during the non-breeding season

The aim of this study was to determine if daily administration of a GnRH analogue (buserelin acetate) to bucks during the non-breeding season increases testosterone concentration and improves sperm quality. Five bucks received a daily dose of buserelin for 10 days, starting on Day 0 (first administration), and another five bucks remained as controls. Testosterone concentrations were greater in treated than in control bucks during the first hours after buserelin administration (P = 0.05), but greater in controls 10 h later (P < 0.01). Sperm mass motility and percentage of motile sperm were greater in treated (3.9 ± 0.6 and 70.1 ± 7.9%, respectively) than in control bucks (1.0 ± 0.6, P < 0.01; 45.0 ± 7.9%, P < 0.05 respectively) on Day 4. Percentage of sperm with normal morphology tended to be greater in treated than in control bucks (81.8 ± 6.2% compared with 63.5 ± 6.4% respectively, P = 0.08). The treatment decreased the percentage of sperm with mid piece defect and with bent tail (7.0 ± 1.5% compared with 12.0 ± 1.5%; 8.0 ± 1.7% compared with 13.5 ± 1.7%, treated and control bucks, respectively, P = 0.05 for both). The square root percentage of sperm with loose but heads with normal structures tended to be less in treated than control bucks (1.3 ± 0.3% compared with 0.4 ± 0.3% respectively, P = 0.06). It was concluded that daily administration of buserelin during the non-breeding season led to a rapid increase in testosterone concentration and improved sperm quality.

Clinical Efficacy of Gonadotropin Releasing Hormone in Treatment of Repeat Breeder Cattle-A Field Study

The study was conducted to determine the effect of GnRH (Buserelin Acetate) administration as a therapy for repeat breeding syndrome in cows. A total of fifty repeat breeder cows with regular estrus cycle, clear vaginal discharge and suffering from ovulatory dysfunction were selected. White side test was carried out to exclude the possibility of sub-clinical genital infection in these animals. The repeat breeder cows which were found to be in estrus and presented for artificial insemination were divided randomly into two equal groups (n=25). Animals of treatment group received 20μg of single intramuscular dose of Gonadotropin releasing hormone (Buserelin Acetate) at the time of artificial insemination. Animals of control group were inseminated at estrus without any treatment. The overall conception rate was significantly higher in treatment group (60%) than control group (4%). Hence the study concluded that using GnRH for non-infectious cases of infertility under field conditions gives encouraging results.Key words: Conception rate, GnRH, Infertility, repeat breeder cow, Reproduction

Profile of LH release in response to intramuscular treatment with kisspeptin in Bos indicus and Bos taurus prepubertal heifers

The main objective of this study was to evaluate the effect of intramuscular (I.M.) administration of different doses of kisspeptin (Kp) on the pattern of luteinizing hormone (LH) release in Bos taurus and Bos indicus prepubertal heifers. Holstein heifers weighing 215.1 ± 38.6 kg (n = 24; aged 5–8 mo) and Gyr heifers weighing 215.4 ± 31.4 kg (n = 24; aged 6–10 mo) were enrolled in this study. The animals were confirmed as non-cyclical by absence of a corpus luteum (CL) as determined by ultrasound scanning of the ovaries and low circulating P4 concentrations (<1.0 ng/mL) evaluated at a 10-day interval (on day −10 and day 0). For each genetic group, heifers were randomly assigned to one of four treatments: Kp at 2.5 μg/kg body weight (Kp2.5), Kp at 5.0 μg/kg (Kp5), Kp at 10 μg/kg (Kp10), or gonadotropin-releasing hormone (GnRH) agonist (0.01 mg of buserelin acetate per heifer), all administered by I.M. injection. All animals responded to the treatments with an LH surge (P < 0.01). There was an effect of breed (P < 0.01) on induced LH release, with Holstein heifers having a greater area under the curve for LH (AUC; P < 0.01) and greater LH peak amplitude (P < 0.01) than Gyr heifers. Nevertheless, greater AUC for LH occurred in Kp10 heifers for both breeds. There was no effect of breed on LH AUC or LH peak amplitude after GnRH agonist treatment. For both breeds, heifers treated with Kp displayed an earlier (P < 0.01) LH peak with a reduced amplitude of the LH peak (P < 0.01) and reduced LH AUC (P < 0.01) compared to heifers treated with GnRH agonist. Thus, both zebu and taurus immature heifers treated with I.M. Kp injection responded with a rapid and dose-dependent LH surge, although even large doses of the native Kp-10 did not mimic the magnitude or duration of the LH surge produced by the GnRH agonist. The early onset of the LH surge after Kp treatment and the short duration suggest that the effects of Kp were likely due to pituitary rather than hypothalamic action. Finally, there seems to be a greater responsiveness to Kp in Bos taurus than in Bos indicus prepubertal heifers, although LH release after GnRH agonist treatment was similar for the two breeds.

Evaluation of the effectiveness and cost of different hormones in stimulating the spawning of thin lipped grey mullet, Liza ramada

ABSTRACTIntroduction: It is known that mullets are not fully mature in captivity and therefore do not lay eggs. Therefore, hormonalpreparations should be used to stimulate spawning.Aim of the work: To evaluate the effectiveness and cost of using different types of hormones; pituitary hormone of carp,human chorionic gonadotropin, gonadotropin - releasing hormones in stimulating spawning of Liza ramada.Materials and Methods: In this study, the pituitary gland was selected for two types of carp; common carp, silver carp, andhuman chorionic gonadotropin, as well as buserelin acetate and triptorelin acetate to stimulate the spawning of Liza ramada.In this regard, these hormones were tested on the rate of ovulation, fertilization rate, embryonic development and hatchingrate, as well as an economic evaluation of the cost of injecting these hormones.Results: The results showed the effectiveness of the used hormones to stimulate ovulation, fertilization and hatching, but atdifferent rates. The use of the pituitary gland of silver carp induced a higher ovulation rate than those of common carp andhuman chorionic gonadotropin. Buserelin acetate induced higher ovulation, fertilization and hatching rates than those oftriptorelin acetate. From the economic point of view, the use of the pituitary gland of silver carp as a stimulant dose and alsothe use of buserelin acetate as a resolving dose is less expensive compared to the use of other tested hormones.Conclusion: The use of the pituitary gland of silver carp and buserelin acetate was effective to stimulate the spawning ofmullets and less expensive.

The Effects of Separate and Combined Use of PGF2α and GnRH Hormones and the Addition of Βeta-Carotene on Fertility Parameters in Dairy Cows with Ovarian Cysts

Background: Ovarian cysts are commonly observed pathologies, which interfere with normal cyclic activity and adversely affect fertility in cows. Beta-carotene is effective in the reduction of reproductive problems by inducing the natural defence mechanisms of the body. There are several methods that can be used for the treatment of ovarian cysts. The separate and combined use of GnRH and PGF2α commonly uses in the treatment of ovarian cysts. Therefore, in the presented study the effects of Beta-carotene (βC) addition for the treatment of ovarian cysts either with GnRH solely or GnRH and PGF2α in combination on the fertility parameters of dairy cows were investigated.Materials, Methods &amp; Results: Seventy-six Holstein Friesian cows having ovarian cysts diagnosed by ultrasonography (USG) were divided into three groups. Cows in Group I (GI, n = 27), were injected with GnRH (Buserelin acetate, 5 mL, im), PGF2α (Tiaprost-trometamol, 5 mL, im) and βC (20 mL/cow, into 4 regions by im route). In Group II (GII, n = 25) GnRH (Buserelin acetate, 5 mL, im) and PGF2α (Tiaprost-trometamol, 5mL, im) were administrated while GnRH (Buserelin acetate, 5 mL, im) solely in Group III (GIII, n = 24). Cysts were monitored via USG, and blood samples were collected on the on day of treatment (day 0) and on the 7th and 14th days following the administrations. Cows shoving oestrous were inseminated and pregnancy diagnoses were performed on the 40th day following insemination. Treatment results showed that there were statistically no significant differences between GI and GII (P &gt; 0.05). Only numerical difference obtained in time from therapy to pregnancy and overall pregnancy index (P &gt; 0.05). Overall pregnancy rate (85 %), first service pregnancy rates (40 %) and overall pregnancy index (2.11) in GI were found significantly higher than GIII (53.3 %; 20 %; 4.12) [P &lt; 0.05]. No significant difference was observed in progesterone (P4) levels between the groups (P &gt; 0.05). It was found that βC administrations significantly increased βC levels in GI than GII and GIII on the 7th and 14th days (P &lt; 0.05).Discussion: One of the most common problems encountered in modern dairy production is the development of ovarian cysts. Treatments for ovarian cyst are numerous and variable, and have changed considerably over the years. In the present study, GnRH and PGF2α were administered together as a combination, and as a result of this combined use, higher percentages were obtained for both pregnancy rate and fertility parameters in GI and GII, in comparison to the group administered with GnRH alone (GIII). Better outcome from combination therapy (GnRH and PGF2α) may be due to the fact that luteal thickening in the walls of cysts was determined by ultrasonography, but P4 values were not identified immediately and the treatments were not categorized in accord with these values. No statistically significant differences were determined between GI and GII concerning the fertility parameters investigated, however numerical and proportional differences were observed. βC levels were significantly higher on day 7 and 14 after treatment in GI which were administered βC additionally to the treatment protocol for ovarian cysts. This statistical difference suggests that administration of βC in combination therapy is also effective in the treatment of ovarian cysts. In conclusion, it was determined that high pregnancy rates were obtained by the combined treatment of ovarian cysts (GnRH + PGF2α) and number of inseminations per conception were at desired limits. Better percentile and numerical fertility parameters were achieved in the group, which additionally received βC, high numbers of infertility cases, βC supplementation could be a viable option for treatment.

Effect of season on dairy buffalo reproductive performance when using P4/E2/eCG-based fixed-time artificial insemination management

This study aimed to compare the reproductive efficiency of dairy buffaloes subjected to TAI protocols based on progesterone, estrogen, and equine chorionic gonadotrophin (P4/E2+eCG) during the fall/winter (n = 168) and spring/summer (n = 183). Buffaloes received an intravaginal P4 device (1.0 g) plus estradiol benzoate (EB; 2.0 mg im) at a random stage of the estrous cycle (D-12). Nine days later (D-3), the P4 device was removed and buffaloes were given PGF2α (0.53 mg im sodium cloprostenol) plus eCG (400 IU im). GnRH (10 μg im buserelin acetate) was administered 48 h after P4 device removal (D-1). All animals were subjected to TAI 16 h after GnRH administration (D0). Frozen-thawed semen from one bull was used for all TAI, which were all performed by the same technician. Ultrasound examinations were performed on D-12 and D-3 to ascertain cyclicity (presence of CL), D-3 and D0 to measure the diameter of the dominant follicle (ØDF), D+10 to verify the ovulation rate and diameter of the corpus luteum (ØCL), and D+30 and D+45 to detect pregnancy rate (P/AI 30d and 45d, respectively) and embryonic mortality (EM). Fetal mortality (FM) was established between 45 days and birth, and pregnancy loss between 30 days and birth. There were significant differences between fall/winter and spring/summer only for cyclicity rate [76.2% (128/168) vs. 42.6% (78/183); P = 0.02]. The others variables did not differ between the seasons: ØDF on D-3 (9.6 ± 0.2 mm vs. 9.8 ± 0.2 mm; P = 0.35); ØDF on D0 (13.1 ± 0.2 mm vs. 13.2 ± 0.2 mm; P = 0.47); ovulation rate [86.9% (146/168) vs. 82.9% (152/182); P = 0.19]; ØCL on D+10 (19.0 ± 0.3 mm vs. 18.4 ± 0.3 mm, P = 0.20); P/AI on D+30 [66.7% (112/168) vs. 62.7% (111/177); P = 0.31]; P/AI on D+45 [64.8%% (107/165) vs. 60.2% (106/176); P = 0.37]; EM [1.8% (2/111) vs. 3.6% (4/110); P = 0.95]; FM [21.9% (18/82) vs. 8.0% (7/87); P = 0.13]; and PL [23.8% (20/84) vs. 12.1% (11/91); P = 0.13]. In conclusion, dairy buffaloes present similar reproductive efficiency in fall/winter and spring/summer when subjected to P4/E2/eCG-based protocol for TAI.

Protection of GnRH analogue by chitosan-dextran sulfate nanoparticles for intravaginal application in rabbit artificial insemination

The present study was designed to prove new rabbit insemination extenders containing aminopeptidase inhibitors (AMIs) with or without chitosan (CS)-dextran sulfate (DS) nanoparticles entrapping the GnRH analogue. In addition, different hormone concentrations were tested in these extenders, evaluating their in vivo effect on rabbit reproductive performance after artificial insemination. A total of 911 females were inseminated with semen diluted with the four experimental extenders (C4 group: 4 μg buserelin/doe in control medium (Tris-citric acid-glucose supplemented with bestatin 10 μM and EDTA 20 mM), C5 group: 5 μg of buserelin/doe in control medium, Q4 group: 4 μg of buserelin/doe into CS-DS nanoparticles in control medium, Q5 group: 5 μg of busereline/doe into CS-DS nanoparticles in control medium). Results showed that fertility was significantly lower in C4 group compared to C5, Q5 and Q4 groups (0.7 versus 0.85, 0.85 and 0.82, respectively). On the contrary, prolificacy was similar in the four experimental groups studied (P > 0.05). We conclude that the CS-DS nanoparticles prepared by a coacervation process as carrier for buserelin acetate allows reducing the concentration of hormone used in extenders supplemented with bestatin and EDTA without affecting the fertility and prolificacy of rabbit females.

Validation of an NMR-Spectroscopic Method for Authenticity Confirmation of Buserelin Acetate Pharmaceutical Substance

The specificity of different variants of an NMR spectroscopic method for authenticity confirmation of buserelin acetate drug substance was estimated by comparing PMR and 13C NMR spectra of buserelin acetate and [5-D-tyrosine]buserelin acetate in various solvents. Spectra of these diastereomers differed most if deuterated water was used as the solvent. Solvent and intramolecular non-bonded interactions influenced proton- exchange tautomerism in the L-histidine residue of the analyzed oligomers. The widths of 13C NMR resonances of this amino acid depended on the proton-exchange rate. The method based on 13C NMR spectroscopy (D2O solvent) was recommended for pharmacopoeial analysis.

Валидация методики подтверждения подлинности фармацевтической субстанции «Бусерелина ацетат» методом ЯМР спектроскопии

Оценена специфичность различных вариантов методики подтверждения подлинности фармацевтической субстанции «бусерелина ацетат» методом ЯМР спектроскопии путем сравнительного анализа спектров 1H и 13C бусерелина ацетата и [5-D-тирозин]бусерелина ацетата в различных растворителях. Найдено, что максимальное различие в спектральных данных диастереомеров наблюдается при использовании дейтерированной воды в качестве растворителя. Показано влияние растворителя и внутримолекулярных невалентных взаимодействий на обменные прототропные превращения в L-гистидиновом фрагменте анализируемых олигомеров. От скорости прототропной таутомерии зависит ширина сигналов данной аминокислоты в спектрах 13C. Рекомендовано использовать в фармакопейном анализе вариант методики, основанный на 13C ЯМР спектроскопии (растворитель — D2O).

The effects of gonadotropin-releasing hormone agonist (buserelin) and orchidectomy on bone turnover markers and histomorphometry in rats

This study aimed to compare the skeletal effect between GnRH agonist therapy and orchidectomy in male rats assessed using serum turnover markers and bone histomorphometry. Three-month-old male Sprague-Dawley rats (n = 46) were divided into three experimental arms, baseline, buserelin, and orchidectomy. In the buserelin arm, the rats received a daily subcutaneous injection of either normal saline or buserelin acetate at 25 µg/kg or 75 µg/kg. In the orchidectomy arm, the rats were either sham-operated or orchidectomized. The rats were euthanized after the three-month treatment. Blood was collected for the evaluation of bone turnover markers. Femurs were harvested for bone histomorphometry examination. A significant increase in serum C-telopeptide of type 1 collagen was observed in the orchidectomized group compared with the sham group (p < .05). Structural histomorphometry analysis showed that both buserelin (25 µg/kg and 75 µg/kg) and orchidectomy significantly decreased the trabecular bone volume, number and significantly increased trabecular separation in rats compared with their respective controls (p < .05). Osteoclast number and eroded surface were significantly increased in both buserelin (25 µg/kg and 75 µg/kg) and orchidectomized group compared with their respective controls (p < .05). As a conclusion, buserelin causes deterioration of bone microarchitecture and increased bone resorption similar to orchidectomy after three months.

Reproductive performance in dairy cows with cystic ovarian disease after single treatment with buserelin acetate or dinoprost.

The treatment of cystic ovarian disease (COD) in dairy cows is still controversial, and some researchers recommend using gonadotropin-releasing hormone (GnRH) regardless of the type of cysts. The aim of this study was to comparatively evaluate the reproductive performance of cows diagnosed with follicular or luteal cystic structures, after treatment with either buserelin acetate (GnRH agonist) or dinoprost (prostaglandin F2-alpha or PGF2α). The diagnosis was established by ultrasonographic examinations performed twice a month starting 40–45 days after calving, until the cows were diagnosed pregnant after artificial insemination. Both types of cysts were treated either with 21 µg buserelin acetate or 25 mg dinoprost, resulting in four subject groups. After treatment, the estrus rate in cows with follicular cysts treated with dinoprost (55.1%) was significantly lower (P<0.05) than in cows treated with buserelin acetate (77.5%) or in cows diagnosed with luteal cysts (77.2% for dinoprost and 72.4% for buserelin acetate). The conception rate was higher (P<0.05) in cows with follicular cysts treated with buserelin acetate (67.7%) than in those treated with dinoprost (60%) or in those with luteal cysts (56.9% for dinoprost and 47.5% for buserelin acetate). These results show that it is preferable to differentiate between the two types of ovarian cysts before treatment. Luteal cysts can be treated with either PGF2α or GnRH analogues, with better results when PGF2α is used. Contrastingly, follicular cysts are better treated with GnRH analogues. When differentiation is not possible, GnRH analogues are recommended over PGF2α.

Establishing an Animal Model of Secondary Osteoporosis by Using a Gonadotropin-releasing Hormone Agonist

Introduction: Orchidectomy is currently the preferred method to induce bone loss in preclinical male osteoporosis model. Gonadotropin-releasing hormone (GnRH) agonists used in prostate cancer treatment can induce testosterone deficiency but its effects on bone in preclinical male osteoporosis model are less studied.Objective: This study aimed to evaluate the skeletal effect of buserelin (a GnRH agonist) in male rats and compare it with orchidectomy.Methods: Forty-six three-month-old male Sprague-Dawley rats were divided into three experimental arms. The baseline arm (n=6) was sacrificed at the onset of the study. In the buserelin arm, the rats received a daily subcutaneous injection of either normal saline (n=8), buserelin acetate at 25 µg/kg (n=8) or 75 µg/kg (n=8). In the orchidectomy arm, the rats were either sham-operated (n=8) or orchidectomized (n=8). All groups underwent in-vivo X-ray micro-computed tomography scanning at the left proximal tibia every month. Blood was collected at the beginning and the end of the study for testosterone level evaluation. The rats were euthanized after the three-month treatment. The femurs were harvested for biomechanical strength and bone calcium determination.Results: The results showed that buserelin at both doses caused a significant decline in testosterone level and deterioration in bone microstructure (p<0.05), but did not affect bone calcium content (p>0.05). Buserelin at 25 µg/kg decreased displacement and strain of the femur significantly (p<0.05). Similar changes were observed in the orchidectomized group compared to the sham-operated group but without any significant changes in biomechanical strength (p>0.05).Conclusion: Buserelin can induce testosterone deficiency and the associated deterioration of bone microarchitecture similar to orchidectomy in three months. However, it may require a longer time to show significant effects on bone strength and mineral content.

Hormonal Management of Postpartum Anoestrus and Suboestrus in Buffaloes, and its Effect on Blood Plasma Constituents

The postpartum (>90 days) true anoestrus (n=12) and suboestrus (n=13) buffaloes were treated with single i/m injection of Buserelin acetate (GnRH) 10 µg and PGF2α (Cloprostenol) 500 µg, respectively. Eight (66.67%) anoestrus and 12 (92.31%) suboestrus buffaloes responded to treatment with mean estrus induction intervals of 13.00±1.85 days and 67.67±0.97 hrs. The overall 3 cyclesÂ’ conception rates were 87.50 (7/8) and 75.00 (9/12) per cent and the mean number of services per conception 2.28 and 2.55, respectively, in two groups. The mean plasma progesterone (P4) levels on the day of treatment and on the day of estrus were basal or much lower in conceived than non-conceived buffaloes, but on day 12 post-AI, the levels increased significantly (p

Pregnancy rate in water buffalo following fixed-time artificial insemination using new or used intravaginal devices with two progesterone concentrations

This study evaluated the pregnancy rate (PR) after timed artificial insemination (TAI) in water buffalo (Bubalus bubalis) during both non-breeding and breeding season, using either a new or reused intravaginal device (IVD) with two different progesterone concentrations. A total of 247 dairy buffalo cows were randomly assigned using a two-by-three factorial design and four replicates to the following groups: (1) new intravaginal device (IVD-New: DIB®, 1.0g of P4, n = 51 or CIDR®, 1.38g of P4, n = 55); (2) intravaginal device previously used once (9days) (IVD-Used1x: DIB, n = 40 or CIDR, n = 51); or (3) intravaginal device previously used twice (18days) (IVD-Used2x: DIB, n = 27 or CIDR, n = 23). On day 0, animals received the IVD plus 10.5μg of buserelin acetate (GnRH) intramuscularly. On day 9, the devices were removed and 25mg of PGF2α plus 500IU of eCG was given intramuscularly. On day 11 (48h after IVD withdrawal), animals received 10.5μg of GnRH and were artificially inseminated 8-12h later. Data were analyzed using Proc Logistic of SAS®. Animals that received IVD-New-DIB, had a significantly higher PR (62.7%; P = 0.0193) compared to animals that received IVD-New-CIDR (40%). Pregnancy rate was not negatively affected by reusing both types of IVD. Overall PR (new and reused devices) was higher (P = 0.0055) in the DIB group (62.7%) compared to the CIDR group (45%). In conclusion, PR was higher in buffaloes treated with devices containing 1.0g of P4 (DIB®) compared to those receiving 1.38g of P4 (CIDR®). Reusing the intravaginal devices did not affect negatively PR/TAI, suggesting that P4 concentrations within the TAI protocols in water buffaloes could be reduced, without impairing their fertility.

70 Effect of Ovulation Stimulus on Biochemical Composition of the Oviduct of Alpaca (Vicugna pacos)

Experiments were designed to determine the effect of ovulation stimulus on the biochemical composition of oviduct fluid in alpacas (Vicugna pacos). Twenty-four adult females were used to determine profiles of protein, albumin, glucose, cholesterol, and triglycerides in oviduct fluid. The animals were stimulated with 1 mL of seminal plasma (SP), 0.042 mg of a gonadotropin-releasing hormone (GnRH) analogue (buserelin acetate; Conceptal, Intervet, Holland), or PBS as control group. The oviduct was removed inmediately after slaughter on Day 2 or 4 after ovulation induction and washed with 3 mL of PBS solution. Determination of the biochemical composition was carried out with specific kits from the FAR Diagnostics Italia laboratory using a semiautomatic biochemical analyzer of the Sinowa China brand, which is based on spectrophotometric evaluation. The results are presented in Table 1. Our results suggest that the method of induction of ovulation affected the biochemical composition of oviduct fluid, including concentrations of albumin, cholesterol, total protein, triglyceride, and glucose. Table 1.Biochemical composition of oviduct fluid (mean ± SEM).

Corpus luteum dynamics after ovulation induction with or without previous exposure to progesterone in prepubertal Nellore heifers

The objectives of this study were 1) to monitor corpus luteum (CL) dynamics after two different protocols of ovulation induction in prepubertal Nellore heifers, and 2) to determine differences in luteal function. Fifty-seven heifers (weight 289.61 ± 32.28 kg, BCS 5.66 ± 0.65, age 17.47 ± 0.81 months) were divided into two groups: GP4+GnRH received a progesterone (P4) device of 3rd use for 10 days, followed by the administration of 0.02 mg buserelin acetate (GnRH) 48 h after removal of the device, and GGnRH received only GnRH. The CLs formed were monitored by ultrasonography every 2 days until their functional regression (decrease in the color Doppler signal and serum P4 concentration < 1 ng/mL), determining their diameter and area, numerical pixel value (NPV), pixel heterogeneity, and vascularization percentage. The peak systolic velocity, end diastolic velocity, resistivity index and pulsatility index (PI) of the ovarian artery and serum P4 concentration were also measured. A lifespan of the CL of more than 16 days was classified as normal-function and of less than 16 days as premature regression. The variables were compared between treatments, CL categories (normal-functional, prematurely regressed or non-functional), days of evaluation, and their interactions using the MIXED procedure of the SAS program (p ≤ 0.05). Three animals of each group (6/57 = 11%) did not respond to treatment, corresponding to an ovulation rate of 89%. There was a higher percentage of normal-function CLs in GP4+GnRH (81%) and a higher percentage of non-functional CLs in GGnRH (52%; P4 concentration < 1 ng/mL in all assessments). Normal-function CLs exhibited a greater area, vascularization percentage and P4 concentration than prematurely regressed and non-functional CLs. Lower diameter, area, NPV and P4 concentration were observed for non-functional CLs, but there was no difference in vascularization percentage compared to prematurely regressed CLs. Progesterone concentration was efficient in diagnosing CL function and was positively correlated with CL area (r = 0.62; p < 0.001) and vascularization percentage (r = 0.38; p < 0.001). Diameter and PI were important for the early diagnosis of non-functional and prematurely regressed CLs, respectively. In conclusion, luteal function differed for the first CL that develops after ovulation induction in prepubertal heifers. Ultrasonographic parameters (diameter, area, NPV, vascularization percentage, and PI) can be used to predict CL function.

Final adult height in long-term growth hormone-treated achondroplasia patients

The objective of this study was to evaluate the gain in final height of achondroplasia (ACH) patients with long-term growth hormone (GH) treatment. We analyzed medical data of 22 adult patients (8 males and 14 females) treated with GH at a dose of 0.05 mg/kg/day. Optionally, tibial lengthening (TL) was performed with the Ilizalov method in 15 patients and TL as well as femoral lengthening (FL) in 6 patients. Concomitant gonadal suppression therapy with buserelin acetate was applied in 13 patients. The mean treatment periods with GH were 10.7 ± 4.0 and 9.3 ± 2.5 years for males and females, respectively. GH treatment augmented the final height +0.60 ± 0.52 SD (+3.5 cm) and +0.51 ± 1.29 SD (+2.8 cm) in males and females compared to non-treated ACH patients, respectively. Final height of ACH patients that underwent GH and TL increased +1.72 ± 0.72 SD (+10.0 cm) and +1.95 ± 1.34 SD (+9.8 cm) in males and females, respectively. GH, TL, and FL increased their final height +2.97 SD (+17.2 cm) and +3.41 ± 1.63 SD (+17.3 cm) in males and females, respectively. Gonadal suppression therapy had no impact on final height.Conclusions: Long-term GH treatment contributes to 2.6 and 2.1% of final adult height in male and female ACH patients, respectively.

What Are the Options for Induction of Ovulation in the Mare in Europe? Buserelin as an Alternative to Human Chorionic Gonadotropin

A pharmaceutical survey conducted among veterinary surgeons practising in Europe (n = 46) revealed that the first choice drug to induce ovulation in the mare is human chorionic gonadotropin (hCG) (91%) and the second choice was a deslorelin implant (Ovuplant; 64.7%). The reason for not using the second choice drug more often was because, although more effective, it was more expensive (66.7%) or more difficult to obtain (20% of responses). In a parallel retrospective study, the efficacy of four different dose rates of buserelin acetate (Suprefact, 1 mg/mL, Sanofi-Aventis; 1 mg, 0.5 mg, 0.25 mg, and 0.125 mg) to induce timely ovulation (within 48 hours of treatment) was compared in 94 mares examined for the occurrence of ovulation three times a day during 225 estrous cycles in 1 year. The ovulatory responses in mares (84.8%, 87.9%, 88.5, and 90%) were similar (P > .05) for all four buserelin doses, 0.125, 0.25, 0.5, and 1 mg, respectively. Transitional mares failed to respond more frequently (34.5% follicles regressed) and took longer to ovulate (36.8% of cycles had an interval to ovulation >48 hours) than cyclic mares (0.0% of follicles regressed and 8.9% of intervals to ovulation >48 hours) following treatment of 0.5 mg of buserelin (P < .05). Furthermore, 21 mares (median age 15.5 years old) were treated with 1,500 IU of hCG in 54 cycles and with buserelin in 137 cycles. The ovulatory response to hCG (25.6%) was lower (P < .05) in these mares than that to buserelin (85.8%).

111 BIOCHEMICAL COMPOSITION OF FOLLICULAR FLUID IN RELATION TO THE STIMULUS TO INDUCE OVULATION IN ALPACAS (VICUGNA PACOS)

Alpacas, like other camelids, are induced ovulators. A study was designed to determine the effect of the ovulation-inducing stimulus on the biochemical composition of follicular fluid. Adult female alpacas (n = 18) were examined daily for 3 days by transrectal ultrasonography using a 5-MHz linear-array transducer (Aloka SSD-500, Tokyo, Japan). When the largest growing ovarian follicle was ≥7 mm, alpacas were given 1.0 mL of seminal plasma intramuscularly (SP, n = 9) or 40 µg of busereline acetate intramuscularly (GnRH, n = 9). A transvaginal transducer with an attached needle guide (Aloka UST-945BP-5) was used for collection of follicular fluid 22 h post-induction. Follicular contents were then centrifuged at 800 × g for 20 min to separate the fluid from the cells. The follicular fluid was collected and stored at –20°C until analysis with a semi-automatic biochemical analyzer (SINOWA, China). The results were glucose 49.17 and 47.95 (mg/dL; P &gt; 0.05), total protein 1.85 and 1.15 (g/dL; P &lt; 0.05), albumin 1.11 and 1.13 (g/dL; P &gt; 0.05), triglycerides 3.94 and 3.16 (mg/dL; P &gt; 0.05), cholesterol 39.01 and 42.5 (mg/dL; P &gt; 0.05), phosphatase 32.68 and 21.36 (IU/L; P &lt; 0.05), alanine aminotransferase 3.66 and 5.07 (IU/L; P &gt; 0.05), and lactate dehydrogenase 42.17 and 27.27 (IU/L; P &gt; 0.05) for SP or GnRH treatments, respectively. Results suggest the need to continue research to explain the effect of possible differences in total protein, cholesterol, and phosphatase on oocyte-expressed genes and follicular development. Research was supported by the project no. 405-PNICP-PIAP-2014-UNMSM.

95 THE USE OF A REARING-FASTING PROGRAM AS AN ALTERNATIVE BIO-STIMULATION METHOD TO HORMONAL EQUINE CHORIONIC GONADOTROPIN TREATMENT TO CONTROL THE EMBRYO RECOVERY OF RABBIT FEMALES

The aim of this study was to investigate the effect of a rearing-fasting program as an alternative bio-stimulation method to hormonal eCG treatments on the embryo recovery of rabbit females. A total number of 119 nulliparous New Zealand White rabbit females at 14 wk old were randomly allocated into 1 of the following 3 groups before the first insemination at 18 weeks old: control group (n = 39), females were fed ad libitum until the first insemination; eCG group (n = 34), females were fed ad libitum and treated with 50 IU of eCG hormone SC 60 h before the first insemination; and r-FP group (n = 46), females were fasted 3 days per week during 3 wk and then allowed to feed ad libitum 1 wk before the first insemination. Sexual receptivity was evaluated for each group on the day of insemination. Only receptive females (74/119) were artificially inseminated and immediately were induced for ovulation by intramuscular injection with gonadotropin-releasing hormone analogue (0.8 μg of buserelin acetate). In 23 receptive females, embryos were recovered postmortem at 72 h post-insemination in each group (n = 7, 9, and 7 in control, eCG, and r-FP groups, respectively). The number of recent corpora lutea on both ovaries (CL), the number of hemorrhagic follicles (HF), the recovery rate (RR), the number of normal embryos recovered in receptive females (NE), the embryo donor rate (DR), and the blastocyst rate (BR) were recorded for all groups. A General Linear Model was performed to analyse CL, HF, and NE, and a chi-square test was used to compare sexual receptivity, RR, DR, and BR in the experimental groups (eCG, r-FP, and control). A significant increase in sexual receptivity was observed in eCG group compared with the other groups (82 v. 50 and 59%; eCG v. r-FP and control groups, respectively; P &lt; 0.05). The CL was significantly (P &lt; 0.05) higher in eCG group (13.8) than in r-FP and control groups (9.1 and 10.3, respectively). However, high incidence of HF was also observed in the eCG group (3.9 v. 0.9 and 1.3 in eCG v. r-FP and control, respectively; P &lt; 0.05). The RR was significantly (P &lt; 0.05) higher in r-FP group (64.1%) when compared with eCG and control groups (38.7 and 20.8%, respectively). The DR was significantly higher for r-FP group compared with the control (100% v. 42.9%, respectively; P &lt; 0.05) and intermediate for eCG group (77.8%). No significant differences were observed in the NE (6.1, 5.7, and 5.0 in eCG, r-FP, and control, respectively). The BR significantly (P &lt; 0.05) decreased in eCG group when compared with r-FP or control groups (4.7% v. 60.0 or 53.3%, respectively). Our results indicated that a rearing-fasting program followed by 1 wk of feed flushing before the first insemination of nulliparous rabbit females could be recommended as an efficient bio-stimulation method to control embryo recovery. However, these results need to be confirmed in a larger scale and several reproductive cycles before widely applied.