Buserelin Research Articles

GnRH34: An alternative for increasing pregnancy in timed AI beef cows

Two experiments evaluated the effects of gonadotropin releasing hormone (GnRH) treatment on fertility of suckled Nelore beef cows treated with an estradiol/progesterone (P4)-based protocol for timed artificial insemination (TAI). Experiment 1 was designed to determine the effect of GnRH administered 34 h after P4 insert removal (GnRH34) on time of ovulation. Suckled cows (n = 34) were treated with 2 mg estradiol benzoate (EB) and an intravaginal insert containing 1.9 g of P4. Eight days later, P4 inserts were removed, and all cows received 150 μg of d-cloprostenol (prostaglandin F2 alpha analogue), 300 IU of eCG, and 1 mg of estradiol cypionate (ECP). On Day 9 (05:00 p.m.), cows were randomly distributed, according to the diameter of the pre-ovulatory follicle, in two treatments: 1) GnRH (n = 17) cows that received 10.5 μg of buserelin acetate, or 2) no further treatment (control, n = 17). Cows treated with GnRH 34 h after P4 insert removal ovulated earlier (P = 0.02) than control cows (66 ± 0.0 and 77.2 ± 4.3 h). Experiment 2 was designed to determine the effect of GnRH34 on the fertility of suckled beef cows. Nelore cows (n = 506) were treated as Experiment 1. On Day 8, cows were painted in the sacrocaudal region to identify cows that displayed estrus. On Day 9 (05:00 p.m.), cows were randomized to receive same treatment as Experiment 1, control (n = 252), or GnRH (n = 254). All cows were TAI 48 h after P4 insert removal. At TAI, estrus was evaluated, and deemed to have occurred in cows without a tail-head chalk mark (>75% paint loss). Cows treated with GnRH 34 h after P4 insert removal had greater (P = 0.01) pregnancy per AI (P/AI) than cows that only received ECP (63.0% and 50.4%). No difference (P = 0.5) was observed in the proportion of cows that displayed estrus between treatments. Furthermore, cows that displayed estrus had greater (P < 0.01) P/AI than cows that did not. Treatment with GnRH, given at 34 h after P4 insert removal, increased (P < 0.05) P/AI in cows that did not show estrus at TAI. In summary, treatment with GnRH 34 h after P4 insert removal was associated with earlier ovulation and resulted in greater P/AI in suckled Nelore cows treated with an estradiol/P4-based protocol for TAI.

Semen quality, testosterone values, and testicular and accessory gland parameters in rams receiving sustained stimulation with low doses of buserelin

Context The use of buserelin, a gonadotropin-releasing hormone (GnRH) agonist, can improve semen quality. Nevertheless, the appropriate dosage, and frequency and time of application, remain to be established owing to the subsequent negative feedback on endogenous production of testosterone described so far. Aims This study aimed to propose a new buserelin application protocol for sperm improvement in Santa Inês rams. Methods Fifteen Santa Inês rams were divided into two experimental groups: the first group (n = 8) received 2.5 μg buserelin acetate; and the second group (n = 7) received saline solution. Treatments were applied for 21 days at intervals of 6 h, totalling four hormonal or saline applications per day. In all animals, macroscopic and microscopic seminal characteristics and freezability, plasma testosterone, pixels of testicular parenchyma, and biometric analysis of testicular and accessory sex glands by ultrasound were evaluated throughout the period of hormonal application and for a further 7 days. Key results Rams receiving buserelin showed a peak of testosterone after the first week (Day 7) of application, with a drop in values at Day 14, followed by negative feedback at Day 21 and return to basal concentrations at Day 28. They also showed improvement of kinetics parameters such as straight line velocity (μm/s: +buserelin 51.5 ± 1.5 &gt; control 46.6 ± 1.6) and linearity coefficient (%: +buserelin 53.5 ± 1.8 &gt; control 47.5 ± 1.9). Ultrasound parameters, pixels of testicular parenchyma, and freezability were not affected by treatment. Conclusions The administration of buserelin was able to improve some sperm kinetics parameters of Santa Inês rams. Implications Low doses of this GnRH analogue can be used; however, further adjustments to the hormonal protocol are needed to obtain an effective improvement in sperm quality.

Combined effect of treatment with intrauterine antimicrobials and GnRH on the conception rate of repeat breeder Frieswal cattle

Repeat breeding in cattle inversely affects the profitability of dairy industry by decreasing the conception rate. Selected 18 repeat breeder cows reared under ideal farm conditions and divided them in to three groups of six animals each viz., group I, II and III with four primiparous cows and two second parity cows in each group. The cows in group I were treated with intrauterine preparation containing aqueous solution of povidone iodine (5%w/v) and metronidazole (1%w/v) (Utrodin IU), followed by uterine lavage with 120 mL of normal saline and inseminated them in the oestrus after skipping the first heat. The animals in group II were treated with an IM injection of buserelin acetate (Gynarich) post AI. The cows in group III were treated with both Utrodin IU and Gynarich post AI. The conception rate observed in group I, II and III were 66.67% (4/6 cows), 66.67% (4/6 cows) and 83.33% (5/6 cows), respectively. The results of the study indicated that combined use of intrauterine preparation containing metronidazole and povidone iodine, along with GnRH was more satisfactory than their individual use in improving the conception rate of repeat breeder Frieswal cattle under farm conditions in Kerala.Â

Response of rams to electroejaculation following the administration of oxytocin and cloprostenol with or without GnRH

The present study aims to evaluate the effect of administering prostaglandin (250 μg cloprostenol) and oxytocin (10 UI) or a GnRH agonist (4.2 μg buserelin acetate) on rams' physiological responses to electroejaculation and the ejaculate's characteristics. The study was performed with a 2 × 2 factorial arrangement, according to whether it used oxytocin and prostaglandin (OXPGF) or GnRH. Therefore, there were four treatments: GControl = saline; GOXPGF = administration of PGF2α and oxytocin; GGnRH = administration of GnRH; administration of GOXPGF + GnRH = GnRH and PGF2α + oxytocin. An interaction between the hormonal treatments in the heart rate occurred: while the heart rate decreased when using OXPGF alone (control: 113.7 bpm vs. GOXPGF: 103.5 bpm, pooled SEM; P = 0.02), it did not modify when applying both treatments simultaneously and administering GnRH (GGnRH: 109.1 bpm vs. GOXPGF + GnRH: 111.5 bpm respectively, pooled SEM = 4.5). The respiratory rate also decreased with the administration of OXPGF (38.7 vs. 46.3 with and without OXPGF, pooled SEM = 10.0, P = 0.003). Administering OXPGF also tended to decrease the temperature (38.77 °C vs. 38.94 °C, with and without OXPGF, respectively, pooled SEM = 0.06; P = 0.056). Blood glucose increased with the administration of OXPGF from 58.7 mg/dL to 62.4 mg/dL (pooled SEM = 1.3, P = 0.014) and varied with time. CK concentrations increased from 641.8 mg/dL to 881.7 mg/dL (pooled SEM = 50.6) with the administration of OXPGF. GnRH administration decreased cortisol concentration from 7.3 ng/mL to 2.1 ng/mL (pooled SEM = 1.4; P = 0.04). The treatments had no effects on the time required for EE, the pulse at which the animals began and ended the ejaculation, or the vocalizations emitted during EE. There were no effects in any evaluated sperm variable. The research concluded that the administration of oxytocin and analogs of PGF2alpha decreased the stress response to electroejaculation, as well as administering GnRH agonist was slightly effective as it only decreased cortisol concentration. Also, these treatments, either alone or combined, did not affect the characteristics of the ejaculate collected.

Effects of buserelin administration on testicular blood flow and plasma concentrations of testosterone and estradiol-17β in rams

This research aimed to examine for the first time the impact of single dose administration of gonadotropin-releasing hormone (GnRH) analog buserelin acetate on the testicular blood flow measurements (peak systolic velocity [PSV], end-diastolic systolic velocity [EDV], resistive index [RI], and pulsatility index [PI]) and the plasma steroids (testosterone and estradiol-17β) concentrations in rams. For this purpose, twelve adult Ossimi rams were randomly assigned into the buserelin group (n = 8) and were injected intravenously (iv) with buserelin acetate (0.008 mg/ram), whereas the remaining rams (n = 4) were injected with normal saline iv and served as a control group. Blood sampling and testicular pulsed-wave Doppler scanning were conducted immediately before (0) and 1, 3, 6, 24, 48, 72, 120, and 168 h after treatment. The control group did not reveal any substantial changes (P > 0.05) in the examined parameters, except for the EDV (P < 0.05). In the buserelin-treated group, a marked reduction in RI and PI values (P < 0.05) occurred 1 to 3 h after administration of buserelin. Besides, there was a significant increase in testosterone plasma concentrations following buserelin treatment. In conclusion, the administration of buserelin triggered a series of substantial changes in the testicular blood perfusion and steroidogenesis that could have a positive effect on testicular function in rams.

Prevalence of reproductive drugs usage in humans and animals: A pilot study in Patiala city of India.

Reproductive drugs that include contraceptive and fertility drugs are used to manage reproductive health in both humans and animals. Contraceptive drugs are mainly used by humans for reversible contraception whereas fertility drugs are mainly used in animals to increase milk production, poultry products and meat production. Usage of these drugs has increased manifold in the last decade. These drugs are excreted through body fluids (mainly urine and milk) that lead to contamination of surface water, milk and animal produce. Consumption of such contaminated products or water results in reproductive disorders and different types of cancers in humans. This questionnaire-based study was designed and conducted involving gynecologists, pharmacies, medical stores and veterinarians in Patiala city and its adjoining areas in India to evaluate the quantitative and qualitative aspects of use of these drugs. A total of 150 survey points were identified with random sampling method. Data was analyzed using appropriate statistical tools. The results showed that contraceptive drugs constitute 86% of reproductive drugs usage in humans. Further, steroidal contraceptives constitute a huge 94.7% share of contraceptive drugs, and of these combined oral contraceptives have 79.79% share among which a combination is ethinylestradiol and levonorgestrel is the most popular (20.92%). The consumption of COCs is higher than that of progestin only pills (Z = 3.39) as well as estrogen only pills (Z = 4.30). In contrast, usage of non-hormonal fertility drugs (89%) dominates over the hormonal class (11%) in humans. The most widely used non-hormonal fertility drug is clomiphene citrate (73.87%). In animals, the prescription rate of hormonal fertility drugs is higher (83%) than the non-hormonal one, where in the most widely prescribed drug is buserelin acetate. These findings are in consonance with the similar studies carried out in US, Europe and Canada which suggest that reproductive drugs usage pattern is more or less similar across the globe. A careful control to discourage indiscriminate use of such drugs is the need of hour to prevent damage of environment and ultimately to the health of living beings.

Testicular steroidogenesis is suppressed during experimental autoimmune encephalomyelitis in rats

Multiple sclerosis (MS) is an autoimmune disease that usually occurs during the reproductive years in both sexes. Many male patients with MS show lower blood testosterone levels, which was also observed in male rats during experimental autoimmune encephalomyelitis (EAE), an animal model of MS. To better understand the causes of decreased testosterone production during EAE, we investigated the expression status of genes and proteins associated with steroidogenesis in the testes. No changes in the number of interstitial cells were observed in EAE animals, but the expression of the insulin-like 3 gene was reduced at the peak of the disease, implying that the Leydig cell functional capacity was affected. Consistent with this finding, the expression of most steroidogenic enzyme genes and proteins was reduced during EAE, including StAR, CYP11A1, CYP17A1 and HSD3B. No signs of testicular inflammation were observed. Recovery of steroidogenesis was observed after injection of hCG, the placental gonadotropin, or buserelin acetate, a gonadotropin-releasing hormone analogue, at the peak of EAE. Together, our results are consistent with the hypothesis that impaired testicular steroidogenesis originates upstream of the testes and that low serum LH is the main cause of decreased testosterone levels during EAE.

Hormonal combinations aiming to improve reproductive outcomes of Bos indicus cows submitted to estradiol/progesterone-based timed AI protocols

The aim was to study reproductive outcomes of Nelore (Bos indicus) cows submitted to a 7-d estradiol (E2)/progesterone (P4)-based timed artificial insemination (TAI) protocol, receiving various combinations of doses and hormones. Primiparous (n = 962) and multiparous (n = 1935) cows were submitted to synchronization (n = 2012) and resynchronization (n = 885 non-pregnant cows at pregnancy diagnosis 30 d after TAI) protocols, following a 2 × 2 × 2 factorial arrangement of eight treatments. At the initiation of the TAI protocol (Day −9), all cows received a 1.0 g intravaginal P4 insert, 2.0 mg E2 benzoate and received (PGF1) or not (PGF0) 0.5 mg cloprostenol sodium (PGF). On Day −2, the P4 insert was removed, all cows received 0.5 mg PGF, 300 IU equine chorionic gonadotropin (eCG) and 0.5 (EC0.5) or 1.0 mg estradiol cypionate (EC1.0). On Day 0, cows were treated (G1) with 8.4 μg buserelin acetate (GnRH) or not (G0), concurrently with TAI. The eight treatments were generated: 1) PGF0-EC0.5-G0 (n = 364), 2) PGF0-EC0.5-G1 (n = 363), 3) PGF1-EC0.5-G0 (n = 363), 4) PGF1-EC0.5-G1 (n = 360), 5) PGF0-EC-1.0-G0 (n = 360), 6) PGF0-EC1.0-G1 (n = 363), 7) PGF1-EC1.0-G0 (n = 361), and 8) PGF1-EC1.0-G1 (n = 363). Pregnancy per AI (P/AI) was greater at first AI compared with resynchronization (58.9 [n = 2012] vs. 54.9% [n = 885]). Presence of CL on Day −9 resulted in more cows expressing estrus (81.3 [n = 680] vs. 67.1% [n = 2033]) and greater P/AI (66.0 [n = 692] vs. 54.9% [n = 2106]). There was no difference in P/AI between cows that received or not PGF on Day -9 (58.7 [n = 1447] vs. 56.6% [n = 1450]). In contrast, PGF tended to increase P/AI of cows with CL on Day −9 (with PGF = 69.1 [n = 375] vs. without PGF = 62.5% [n = 317]). Cows that received 1.0 mg EC expressed more estrus than those treated with 0.5 mg (73.8 [n = 1414] vs. 67.9% [n = 1398]) and had greater P/AI (60.2 [n = 1447] vs. 55.1% [n = 1450]). P/AI was greater in cows treated with GnRH at TAI (59.8 [n = 1449] vs. 55.5% [n = 1448]), particularly in cows that did not show estrus (52.7 [n = 393] vs. 38.1% [n = 420]). Moreover, GnRH on Day 0 increased P/AI in cows with BCS < 3.0 (57.1 [n = 723] vs. 48.6% [n = 698]), in primiparous (50.1 [n = 465] vs. 41.9% [n = 497]) and in cows that received 0.5 mg EC (58.9 [n = 723] vs. 51.3% [n = 727]). In conclusion, 1.0 mg of EC on Day −2 and GnRH at TAI improved P/AI, but the combination of a higher dose of EC and GnRH treatment at AI did not enhance this effect. Furthermore, GnRH improved P/AI especially in Bos indicus cows with lower expression of estrus, such as primiparous, thinner cows, and cows treated with 0.5 mg of EC.

CICLO ANUAL REPRODUTIVO DE RÃS-TOURO (Lithobates catesbeianus) NO ESTADO DO RIO DE JANEIRO: ANNUAL CYCLE OF REPRODUCTION OF BULLFROGS IN THE STATE OF RIO DE JANEIRO

Raniculture is an activity already established in the state of Rio de Janeiro, but it has an obstacle in its productive chain, as in most Brazilian states, which interrupts the reproduction of frogs during the low temperature period (autumn and winter). The reality of the lack of studies in the area of ??bullfrog reproducers, the present study had as main objective to study the reproductive cycle of the reproducers in acclimatized conditions for a year. Adapted was a reproduction sector in a ranario in the state of Rio de Janeiro. During the period of one year, bullfrog males and females were sampled and placed in an adapted experimental stall, the frogs were fed and evaluated through biometrics. In the stall the water temperature controlled at 25 ° C, a photoperiod of 14 hours of light and 10 hours of darkness and humidity of 80%, each animal was considered a repetition. Periodic semen collections and attempts at artificial fertilization with the hormone Buserelin Acetate were performed periodically to induce sexual gametes. In the period from August to June artificial fertilizations were carried out, in just two months, in December four females were fit and in March five females, males from November were already fit. In June he completed the stall with five females and 10 males, that is, a little more than half. Only three spawns hatched and resulted in tadpoles, 5,850 in total and an average of 1,950 per spawn.

Buserelin Inhibits the Immunosuppressive Activity of Regulatory T Cells through the Protein Kinase A Signaling in a Central Precocious Puberty Model

ABSTRACT Background Gonadotropin-releasing hormone analogs (GnRHas) are used for treating central precocious puberty (CPP). However, their roles in the regulation of immune cells especially regulatory T cells (Tregs) remains elusive. Therefore, we characterized buserelin-induced phenotypical and functional changes of Tregs. Methods A rat CPP model was established followed by administration of buserelin acetate. Flow cytometry was used to evaluate the expression of functional molecules in splenic Tregs. The suppressive activity of Tregs was determined by the suppression assay. GnRHR expression in Tregs was assessed by flow cytometry analysis and Immunoblotting. Normal Tregs were then stimulated and treated with buserelin acetate in vitro. After that, Foxp3 expression, Treg proliferation, and cytokine production were analyzed by flow cytometry. Intracellular signaling was evaluated by Immunoblotting, and Treg function was determined by the suppression assay. Results After in vivo buserelin treatment, the frequency of splenic Tregs was decreased, with the reduction in the expression of Foxp3, IL-10, and TGF-β. The suppressive activity of Tregs was weakened. Buserelin down-regulated Foxp3 expression while promoting the expression of RORγt and IL-17 in Tregs through activating the protein kinase A (PKA) pathway in vitro. The PKA inhibitor H-89 abolished the effect of buserelin and enhanced Treg function. Conclusion Buserelin impaired the immunosuppressive activity of Tregs through the PKA signal pathway. Buserelin-induced activation of PKA signaling down-regulated Foxp3 expression while promoting RORγt expression in Tregs, and subsequently weakened Treg function. Our study indicates the necessity of monitoring Treg activity in CPP patients to avoid potential autoimmunity or inflammation.

The effect of ovulation induction of GnRH following a short-term estrous induction protocol in Saanen goats

The current study was to compare the effect on the ovulation time and estrus parameters of a GnRH agonist (buserelin acetate) administered 24 or 36 h following a short-term estrus induction and synchronization treatment in non-lactating Saanen goats during the transitional period. Goats received 20 mg FGA sponges during 6 days plus 300 IU eCG and 125 µg d-cloprostenol 24 h prior to sponge removal. After removal of the sponges, goats were given either 1 ml physiological saline (0.9% NaCI) solution (Group 1 ; n = 9) after 12 h, 0.004 mg GnRH (buserelin acetate, Group 2 ; n = 10) after 24 h or 0.004 mg GnRH (Group 3 ; n = 10) after 36 h. The follicle development and ovulation in the ovaries were monitored by transrectal ultrasonography starting from the sponge application until the fifth day of the estrus cycle. Blood samples were collected on the same days to determine the plasma concentrations of progesterone (P4) and estradiol (E 2 ). As no statistical differences was detected in any synchronization parameters, ultrasonic evaluations and plasma P4 and E 2 concentrations among all groups, thus averages were assessed. The total estrus response, duration of the induced estrus, interval from sponge removal to onset of the induced estrus, time occurrence of ovulation from sponge removal and estrus onset to ovulation were recorded to be 93.10%, 33.66 ± 2.85 h, 27.48 ± 2.71 h, 48.05 ± 1.24 h and 21.51±2.37 h, respectively. The total ovulation rate, total number of ovulations per doe, largest follicle diameter and second largest follicle diameter were recorded to be 93.10%, 2.01±0.22, 6.85 ± 0.26 mm and 6.12 ± 0.24 mm, respectively. Results of this study indicate that administration of GnRH at 24 h or 36 h after sponge removal does not affect plasma P4 and E 2 concentrations, estrus parameters and ovulation time in estrus induction and synchronization in goats during the transition period.

Effect of GnRH treatment following a short-term estrous induction protocol on estrus and ovulation in Saanen goats, during the transitional period

The objective of this study was to compare the effect on the ovulation time and estrus parameters of a GnRH agonist (buserelin acetate) administered 24 or 36 h following a short-term estrus induction and synchronization treatment in non-lactating Saanen goats during the transitional period. Goats received 20 mg FGA sponges for 6 days plus 300 IU eCG and 125 μg d-cloprostenol 24 h prior to sponge removal. After removal of the sponges, goats were given either 1 ml physiological saline (0.9% NaCI) solution (Group1; n = 9) after 12 h, 0.004 mg GnRH (Group2; n = 10) after 24 h or 0.004 mg GnRH (Group3; n = 10) after 36 h. The follicle development and ovulation in the ovaries were monitored by transrectal ultrasonography starting from the sponge application until the fifth day of the estrus cycle. Blood samples were collected on the same days to determine the plasma concentrations of progesterone (P4) and estradiol (E2). No statistical differences among groups were detected in any synchronization parameters, ultrasonic evaluations and plasma P4 and E2 concentrations. The evaluation of pooled data showed that the response of Saanen goats to treatments was comparable to the results of other published trials. Results of this study indicate that administration of GnRH at 24 h or 36 h after sponge removal, at the end of a short estrus induction and synchronization protocol, does not affect plasma P4 and E2 concentrations, estrus parameters and ovulation time in goats, during the transition period.

Effect of Dietary Supplementation of Crushed Soybean and Flaxseed on Estrus Attributes in Postpartum Crossbred Cows

The objective of the present study was to examine the effect of dietary supplementation of crushed soybean and flaxseed on estrus attributes and preovulatory follicle size in postpartum cows. A total 20 postpartum crossbred multiparous cows from 2nd to 4th lactation with normal calving history were selected and randomly divided into two groups viz. Group 1 (T1) cows fed with roasted crushed soybean @10% of DM (300 g /100 Kg of body weight/day) till 50 and then after continued with crushed flaxseed @ 15% of DM (300 g /100 Kg of body weight/day) and group 2 (T2- without additional fat). Cows from both the groups were subjected to an ovsynch synchronization protocol on day 60 postpartum and observed for induced estrus response, time required for onset of induced estrus, intensity and duration of induced estrus. The diameter of preovulatory follicles was studied transrectaly with a linear-array 7.5 MHZ probe before the second buserelin acetate injection. The dietary supplementation of soybean and flaxseed influenced estrus response, intensity of estrus and time required for onset of induced estrus and duration of estrus however the difference was statistically non significant. At the same time the mean preovulatory follicle diameter was significantly higher in supplemented group.

9 Fixed timed artificial insemination during different seasons in Argentina (2016–2019)

The objective of this work was to evaluate pregnancy rates in buffaloes subjected to fixed-time AI (FTAI) during the year in Argentina. The data analysed was collected between 2016 to 2019 in a farm located in Paso Florentin City (27°20′33″ latitude and 58°08′27″ longitude) in Corrientes, Argentina. The animals were grazing native pastures (Andropogon lateralis, Paspalum almum). Ten fixed-time AI (FTAI) sessions were performed, 6 within the favourable season (BS, March–June) and 4 in the outbreeding season (OBS; September–December). Murrah and Mediterranean breed (n=141) buffaloes were used. All animals were healthy, without anatomical alterations and with normal reproductive tracts. Heifers (H), adult females with calf (AFC), and dry buffaloes (DB) were used. The average (±s.d.) weight of the animals were 459.0±37.5kg, 581.3±53.6kg, and 583.3±53.1kg, respectively. The presence of corpus luteum (CL) or a dominant follicle (≥8mm) at the beginning of the protocol was recorded. BS ovulation induction: Ovsynch (n=182); Day 0 gonadotrophin-releasing hormone (GnRH; 100μg, busereline acetate), Day 7 prostaglandin F2α (150μg, cloprostenol), Day 9 GnRH and FTAI 16h after the last GnRH injection. For the OBS (n=85): Day 0 intravaginal device (700mg of P4) + oestradiol benzoate (0.2g), Day 8 removal of the device + prostaglandin F2α + oestradiol cypionate (0.1g) + eCG (400IU) and Day 10 FTAI (52–56h) after device removal. Semen from 5 bulls of proven fertility was used, and the same technician performed all the inseminations. A specifically designed format to record the data were used and the average±s.d. of the physiological and the meteorological parameters were calculated. Pregnancy was detected 40 days after FTAI using ultrasonography. Comparison within variables were performed using ANOVA and Tukey test, with InfoStat-Statistical Software. A total of 267 inseminations were performed, and the overall pregnancy rate (PR) was 37.45% (100/267). Comparing BS with OBS, PR were 40.7% (74/182) and 30.6% (26/85) (P&amp;lt;0.005). Heifers had a higher PR (51.5%) than suckled buffaloes (38.8%) and dry buffaloes (20%) during the BS (P&amp;lt;0.05). In the OBS, there were no differences among categories on PR for [36.36 (4/11) H, 28.57 (12/42) AFC, 19.51 (8/41) DB; P&amp;gt;0.05]. The presence of a CL at the beginning of the FTAI protocol had a positive effect on PR during the year in all categories [31.79% (55/173) H, 40.42 (38/94) AFC, 21.51 (17/79) DB vs. 25.45% (28/110) H, 29.68 (19/64) AFC, 19.56 (9/46) DB; P&amp;lt;0.05]. Season had a significant effect over PR, but rain, temperature, daylight, and humidity did not differ during the year. These results show the feasibility of FTAI in water buffalo, confirm that it is possible to maintain the PR during the year, and demonstrate successful performance of protocol induction in cyclic females during the year. More research is needed to improve PR in buffaloes in Argentina, to explain the low results in suckled and dry adult buffaloes, and to analyse the effect of meteorological conditions over the breeding performance of the animals.

113 Different doses of equine chorionic gonadotrophin on pregnancy and twin rates of Bos taurus beef heifers subjected to J-Synch protocol for fixed-time artificial insemination

The objective was to evaluate the effect of different doses of equine chorionic gonadotrophin (eCG) on pregnancy (P/AI) and twin rates of beef heifers in a progesterone and oestradiol-based treatment (J-Synch protocol) for fixed-time AI (FTAI). A total of 1,404 Bos taurus beef heifers with a body condition score 4.8±0.5 (mean±s.e.m., scale 1–8) were used in three different locations. The presence of a corpus luteum (CL) was determined by ovarian ultrasonography (5.0MHz) at the beginning of the J-Synch protocol. On Day 0, the heifers received 2mg of oestradiol benzoate (intramuscular, IM) associated with an intravaginal device containing 0.5g of progesterone. At device removal, on Day 6, 500µg of cloprostenol sodium was administered IM and the females were randomly assigned to one of two experimental groups to receive 200 (n=702) or 300 (n=702) IU of eCG (Zoetis) IM. Heifers were also tail-painted. On Day 0 females with paint rubbed-off were FTAI 64 h after device removal, and those that remained with the paint received 8 μg of buserelin acetate 64 h after device removal to be FTAI 8 h later. FTAI was performed at 64 to 72h after device removal, and pregnancy diagnosis was performed by ultrasonography 30 to 35 days after insemination. Data were analysed by logistic regression using GLMM. The results are shown in Table 1. Pregnancy rate was not different between heifers treated with 200 or 300IU of eCG (P=0.513) and was not affected by the presence of CL at the beginning of the protocol (P=0.513). Twin rate was greater in heifers treated with 300IU than with 200IU of eCG (P=0.005), and it was not affected by the presence of CL (P=0.362). Interaction between eCG treatment and presence of CL was not significant for pregnancy or twin rates (P=0.532). In conclusion, although 300IU of eCG increased the twin rate compared with 200IU, no differences were found in P/AI. We suggest that the dose of eCG in the J-Synch protocol could be adjusted to 200IU in Bos taurus beef heifers. Table 1. Pregnancy per AI (P/AI) and twin rates obtained with different doses of eCG (200 or 300IU) in a J-Synch protocol for fixed-time AI in cycling (CL) and anestrous (no CL) Bos taurus beef heifers Variable 200 IU 300 IU P-value CL no CL Total CL No CL Total eCG CL eCG×CL P/AI (%) 61.6% (135/219) 59.8% (289/483) 60.4% (424/702) 60.2% (133/221) 59.5% (286/481) 59.7% (419/702) 0.513 0.513 0.513 Twin rate (%) 3.0% (4/135) 3.5% (10/289) 3.3% (14/424) 6.8% (9/133) 9.4% (27/286) 8.6% (36/419) 0.005 0.362 0.532

Efficacy of clomiphene citrate in augmenting fertility of anoestrous goats

A study was designed to assess the efficiency of clomiphene citrate in augmenting fertility in anoestrous goats. Fifty-two pluriparous goats (2-6 yr old) with the history of anoestrus since last kidding were taken for the study. Animals were divided into two groups. Animals of Gr-I (n=26) were treated with TANUVAS mineral mixture type 2 (10 g/day) for 20 days orally. Animals of Gr-II (n=26) were treated with TANUVAS mineral mixture type 2 (10 g/day) for 20 days followed by clomiphene citrate 150 mg (Ovulanta-Kit, Vet Mankind, India) orally for five days. Follicular activity was observed by ultrasonography after supplementation of mineral mixture in both the groups until pre-ovulatory follicle size of > 5 mm, followed by administration of buserelin acetate (40μg, intramuscular). In Gr-I, 16 (61.5%) animals showed pre-ovulatory follicles in 52 days interval whereas in Gr-II, 24 (92.3%) animals showed in five days post treatment with clomiphene citrate. In both the groups, 50.0% of the animals were allowed for natural mating and the remaining were artificially inseminated (AI) with frozen semen. In Gr-I, 37.5% (3/8) and 62.5% (5/8) animals conceived by natural mating and AI, respectively; whereas, the corresponding values in Gr-II were 75.0% (9/12) and 100.00% (12/12). The results showed the potent efficiency of clomiphene citrate in the treatment of anoestrus in goats.

Buserelin Acetate Reduces Mortality and DNA Defragmentation of Bovine Sperm Cells Exposed to Oxidative Stress

Buserelin Acetate Reduces Mortality and DNA Defragmentation of Bovine Sperm Cells Exposed to Oxidative Stress

Effects of Buserelin acetate and semen extension on fertility in rabbit does under artificial insemination

The productivity of rabbit farms can be increased and become more homogeneous through the use of Artificial Insemination (AI). However, this possibility is limited with low conception in artificially inseminated does without ovulation induction. This study aimed at determining the conception rate of rabbit does induced with buserelin acetate and inseminated with extended semen at varied dilution ratio. A total number of Twenty eight multiparous non-lactating rabbit does were randomly allotted into four treatments housed individually in a completely randomised design. Rabbits were used as a teaser for semen collection using an artificial vagina and after semen collection and evaluation; ejaculates from ten bucks with more than 60% motility were pooled and extended. Forty eight hours before the AI, the does were hormonally synchronized (i.m) for oestrus with 20IU PMSG. Does in treatment 1(control) were inseminated with unextended semen without buserelin but injected with normal saline, while does on treatments 2, 3 and 4 were inseminated with extended semen in ratio 1: 1, 1:2 and 1: 3 (semen: extender), respectively and were all intramuscularly induced using 0.8µg of buserelin after insemination. Results showed that some of the does induced with buserelin acetate intramuscularly (treatments 2, 3 and 4) were pregnant, while none of the control rabbits was pregnant. The ratio 1: 1 extended semen (treatment 2) recorded the highest percentage conception (85.71%) followed by treatment 3 (71.43%) and treatment 4 (57.14%). There was significant (P&lt;0.05) difference in gestation length (32.50, 31.00 and 32.75), litter size (4.83, 8.60 and 3.25), live kits at birth (3.50, 6.60 and 1.75) for treatments 2, 3 and 4 respectively and the average litter weight was not significantly different among the treatments. This study suggests that diluting semen in ratio 1: 1 produced highest conception rate with intramuscular administration of 0.8µg buserelin acetate than extending semen in ratios 1: 2 and 1: 3.

Weaned Sows with Small Ovarian Follicles Respond Poorly to the GnRH Agonist Buserelin.

Simple SummaryThis study evaluated the influence of mean ovarian follicle size and the season of weaning on the effectiveness of administering the GnRH agonist buserelin to synchronize ovulation in weaned sows. The results from 352 sows demonstrated that sows with small follicles (<0.5 cm in diameter) at treatment are poor responders, a condition more frequent among sows weaned in summer–autumn than in those weaned in winter–spring.The GnRH agonist buserelin (GnRH), used to synchronize ovulation in weaned sows, attains only 70–80% effectivity, owing to several reasons of ovarian origin. This study evaluated in particular whether mean ovarian follicle size at treatment and the season of weaning are among those influencing GnRH responsiveness. The experiment was carried out in a temperate-region farm with 352 sows of 1–6 parities weaned either in winter–spring (WS, 174 sows) or in summer–autumn (SA, 178 sows). The sows were randomized into two groups: GnRH (10 µg of buserelin acetate at 86 h after weaning, 172 sows) and control (180 sows). The ovaries were transrectally scanned from weaning to ovulation and the sows clustered according to their mean follicular size at treatment time: small (<0.5 cm in diameter), medium (0.5 to 0.64 cm) and large (0.65 to 1.09 cm). In total, 88.33% of the GnRH-treated sows ovulated, with 82% of them within the expected time window (120–132 h after weaning). In contrast, 95.45% of the unresponsive sows had small follicles at the time of treatment and were mostly weaned in SA (20.45%) than in WS (4.76%). In conclusion, the conspicuous presence of sows having small ovarian follicles at treatment time compromises the efficiency of the GnRH agonist buserelin to synchronize ovulation in weaned sows, which occurs more frequently in summer–autumn weaning.

Evaluation of Double Ovsynch Protocol in Acyclic Jaffarabadi Heifers and Buffaloes with Respect to Ovarian Dynamics, Hormonal Profile and Fertility

Background: Anestrus is one of the most commonly encountered infertility problems in cattle and buffalo in India. Jaffarabadi is one of the heaviest buffalo breeds of the world and is a native of Saurashtra region of Gujarat. The breed is known for poor reproductive efficiency. To improve its reproductive efficiency, this study was undertaken on acyclic Jaffarabadi animals employing double Ovsynch protocol and its assessment through ovarian dynamics and blood biochemical and endocrine profile on a farm. Methods: The study included acyclic post-pubertal Jaffarabadi heifers (age 42±2 and 48±2 months; Gr-I and Gr-II, n=6 each) and the postpartum lactating acyclic buffaloes (Gr-III, n=6) using a double Ovsynch protocol, which consisted of i/m injections of 20 µg Buserelin acetate on days 0, 10, 17 and 26 and 500 µg Cloprostenol sodium on days 7 and 24, with a timed insemination on day 27. Ovarian dynamics was monitored by performing ultrasonography using real-time B-mode ultrasound scanner together with blood sampling for hormonal and biochemical profile on each day of hormone therapy and then on days 0, 12, 21 and 35 post-AI. The animals inseminated at induced estrus/FTAI were followed for return to estrus, if any. Pregnancy was confirmed in non-return cases on day 35 by ultrasonography and on day 70 by per rectal examination. The findings on ovarian dynamics, plasma endocrine and biochemical profile were compared statistically between groups and periods and fertility rates between groups. Result: In animals of treatment group I and II, a significant (p less than 0.05) increase in numbers of small follicles was observed on day 26. Number of large sized follicles was significantly (p less than 0.05) higher on day 26 in comparison to day 0 and day 7 in group III animals. Large and subordinate follicular diameters increased gradually, but the differences between periods were significant (p less than 0.001) only in group III with the highest diameter of large follicle on day 17. Plasma FSH and LH concentrations differed significantly (p less than 0.001) among groups at all-time intervals. Plasma LH in group I and III differed significantly (p less than 0.001). Plasma estrogen level was significantly (p less than 0.05) higher in group II than group III. Plasma progesterone concentrations in group I and II animals were significantly higher on day 35 post-AI. Plasma insulin levels were significantly (p less than 0.01) lower on all days for group III animals than group I and II. Blood glucose level was significantly (p less than 0.001) higher in group I on day 17 as compared to group II and III. Plasma total cholesterol was significantly (p less than 0.05) higher in group III as compared to group I and II. The conception rates at first service/FTAI in double Ovsynch treated animals of group I, II and III were 66.66, 83.33 and 16.66 %, respectively. Thus it was concluded that ovarian structures and the plasma endocrine profile reflected the ovarian response to different hormonal injections and that double Ovsynch protocol could be a better choice for improving conception rate in post-pubertal acyclic Jaffarabadi buffalo heifers as compared to multiparous acyclic buffaloes.