Dose Of GnRH Research Articles

EFFECT OF LUTEAL REGRESSION ON CONCEPTION RATES IN POSTPARTUM ANESTRUS MURRAH BUFFALOES USING G48 AND G56 OVSYNCH PROTOCOLS

The present study aimed to investigate the effect of luteal regression on the conception rates in postpartum anestrus graded Murrah buffaloes. Ovsynch protocols: G48 group (n=10) and G56 (n=10) graded Murrah buffaloes, both received a 20 µg dose of GnRH on day 0, followed by 500 µg of PGF2α on day 7. On day 9, a final dose of 20 µg of GnRH was administered 48 hours after PGF2α for G48 and 56 hours after for G56. Fixed-time artificial insemination (FTAI) was conducted at 16-21 hours after 2nd injection in both groups. The luteal regression rates in both the groups were evaluated by progesterone hormone (P4) assay at different days of treatment. The results showed that in both groups, the concentration of P4 differed significantly (P<0.05) between and within groups at different days of treatment. In conclusion, it was found that the G56 group (70.00 per cent) had a higher overall conception rate than the G48 group (50.00 per cent) due to better luteal regression.

Fertility Assessment of Sexed Semen with Synchronized and Spontaneous Estrus in Crossbred Cows

Background: With the commercial introduction of sexed semen, its use has been recommended for insemination at observed estrus, avoiding the use of a fixed-time insemination due to inherent variation in success of timed programmes. The use of the Ovsynch protocol with sexed semen at defined conditions such as normal clinical and reproductive status of lactating cows might result in a pregnancy rate comparable to that achievable at insemination upon detection of spontaneous estrus with sexed semen. Considering this rationale, present research was implemented with the effect of fertility on synchronized and spontaneous estrus with sexed semen. Methods: Post-partum multiparous crossbred cows (n=28) were categorized as a group I (Spontaneous; n=14) and group II (Ovsynch; n=14). The fourteen cows from group I were inseminated with sexed semen at observed estrus after initial treatment with vitamin AD3E and H, urimin and supplemented with chelated mixture and the fourteen cows from the group II were synchronized with Ovsynch synchronization protocol (Inj. Buserline acetate 10 µg I/M) on day 0, (Inj. Cloprostenol sodium 500 µg) on day 7 and (Inj. Buserline acetate 10 µg) I/M on day 9. Thereafter, timed artificial insemination (TAI) was performed 16-20 hours after 2nd dose of GnRH with sexed semen. Result: The percent intense type of intensity recorded numerically higher in induced estrus. The first service conception rate was higher in spontaneous estrus with the overall conception rate 39.28%. Cows with 60-100 days in milk was showed high conception rate with sexed semen, as the parity increases the conception rate decreases with sexed semen The overall proportion of female calves born was 90.90%.

242 Comparison of GnRH administration day in the 7&7 Synch versus 8&6 Synch Protocol for fixed-timed artificial insemination in beef heifers

Abstract The research aimed to investigate the impact of reducing the time interval for progesterone exposure on the ovulatory follicle just before performing fixed-timed artificial insemination (FTAI). This was achieved by adjusting the timing of administering a gonadotropin-releasing hormone agonist (GnRH; specifically, 100 µg gonadorelin, known as Cystorelin). The study assessed the effectiveness of two estrous synchronization protocols, the “7 & 7 Synch” and a modified protocol, by examining estrus expression (EE) and the resulting pregnancy rates (PR) following FTAI. The research utilized frozen conventional Angus semen from Select Sires, Inc. (Plain City, OH), and involved 66 Angus-cross heifers from the beef cattle research unit near Fayetteville at the University of Arkansas. To ensure consistency, the heifers were divided into two treatment groups based on their cyclicity status (CYC) and age. CYC status was determined by assessing a reproductive tract score (RTS) 1 wk before the synchronization process. RTS scores ranged from 1 to 5, with RTS 1-3 indicating pre- or peripubertal status and scores of 4 and 5 indicating cycling. Heifers with an RTS of 1 and 2 were excluded from the study before synchronization commenced. Both treatment groups involved the insertion of a controlled internal drug-releasing device (CIDR; specifically, Eazi-breed, containing 1.38 g of progesterone) into the vagina on d -14. Simultaneously, a prostaglandin F2α analogue (PGF; 500 µg cloprostenol sodium, known as Synchsure) was administered. In the first treatment group (7&7), GnRH was administered on d -7, while in the second group (8&6), GnRH was given on d -6. In both cases, PGF was administered on d 0 when the CIDR was removed, precisely 72 ± 1 h before FTAI, along with another dose of GnRH. Estrus expression (EE) was assessed during FTAI by examining Estrotect patches (Rockway Inc., Spring Valley, WI). EE was considered present when a patch had 50% or more of its color rubbed off, and it was deemed absent when less than 50% of the color had worn off. Pregnancy rates (PR) were determined through ultrasound examination on d 55. EE and PR were analyzed by treatment using the GLIMMIX procedure on SAS 9.4 (SAS Institute Inc., Cary, NC). Statistical differences were declared at α ≤ 0.05 and tendencies declared between 0.05 < P ≤ 0.1. Heifers on the 8&6-d protocol had greater rectal temperatures at breeding compared with 7&7-d heifers (P < 0.0001). AI pregnancy rates were greater in heifers on the 8&6-d protocol compared with the heifers on 7&7-d protocol (P = 0.625) with average pregnancy rates of 39.4% and 30.3%, respectively. Overall, pregnancy rate was greater as well for the 8&6-d heifers compared with the 7&7-d heifers (P = 0.044), with mean overall pregnancy rates of 78.8% and 54.5%, respectively.

Effect of 200 μg of gonadorelin hydrochloride at the first GnRH of a CO-Synch program on ovulation rate and pregnancies per artificial insemination in Holstein heifers

The initial ovulatory response during synchronization programs is often low in dairy heifers, largely due to follicular dynamics and hormonal dynamics. Specifically, the progesterone (P4) concentration at the time of the first GnRH treatment in a breeding program can influence the LH response, often resulting in a suboptimal ovulatory response. The objective of this study was to determine the effect of the highest label dose 200 μg (100 μg vs. 200 μg) of GnRH (50 μg of gonadorelin hydrochloride per mL; Factrel, Zoetis Inc. Madison, NJ) at the first GnRH of a 6-d CO-Synch plus P4 device program on ovulatory response and pregnancy per AI (P/AI) in first service in Holstein heifers. A total of 1,308 Holstein heifers were randomly allocated at the beginning of a 6-d CO-Synch program at day 0 to receive either i.m. treatment of 100 μg (2CC, n = 655) or 200 μg (4CC, n = 653) of GnRH. Also, at d 0, heifers received an intravaginal insert with 1.38 g of P4 (Eazi-Breed CIDR Cattle Insert, Zoetis Inc.). On day 6, the insert was removed, and i.m. treatment of 25 mg of PGF2α (12.5 mg of dinoprost tromethamine/mL; Lutalyse HighCon Injection, Zoetis Inc.) was administered. On d 7, a second i.m. treatment of 25 mg of PGF2α was given, followed on d 9 by concurrent i.m. treatment of 100 μg of GnRH, and timed AI. A subset of 396 heifers had their ovaries scanned to evaluate ovulatory response, and blood samples were collected to measure the serum concentration of P4 at d 0 and d 6 of the study. The P4 concentrations at d 0 were categorized as low (≤3 ng/mL) or high (>3 ng/mL). The ovulatory response was greater for heifers receiving 4CC than 2CC at d 0 (54.7% vs. 42.8%). The ovulatory response was greater for low P4 than high P4 at d 0 (54.3% vs. 37.8%). However, we did not observe an interaction between treatment and P4 concentrations (low P4 2CC = 48.6% vs. high P4 2CC = 30.0%; low P4 4CC = 60.0% vs. high P4 4CC = 45.5%). The receiver operating characteristic curve analysis indicated that P4 concentrations at d 0 treatment could predict the ovulatory response, although the area under the curve was only 0.6. As expected, heifers that ovulated had increased P/AI (no = 55.6% vs. yes = 67.7%); however, we found no effect of treatment on P/AI (2CC = 63.3% vs. 4CC = 59.6%), and no interactions between treatment and ovulation and treatment and P4 (high vs. low) for pregnancy outcomes. In summary, P4 concentration and increasing the dose of GnRH at d 0 positively affected ovulatory response in Holstein heifers. However, there was no interaction between treatment and P4 on ovulation and no subsequent impact of GnRH dose on P/AI.

The Effect of Reduced GnRH Dose on Ovulation and Follicular Dynamics in Ovsynch Programme of Pure and Bunaji-Crossbred Cows.

Our objective was to compare the efficacy of reducing GnRH dose from 100µg to 50µg on the formation of ovulation and sizes of ovarian structures following Ovsynch in apparently healthy Bunaji and Friesian × Bunaji Cows. Thirty female multiparous-apparently-healthy adult [Bunaji (n = 15) and Friesian × Bunaji (n = 15)] breeds of cattle were used. Five cows each were allocated randomly to three groups [control; full dose (FD), and half dose (HD)]. Cows in the control group were treated with 2ml normal saline while FD-group received 100µg lecirelin on day 0, with 500µg clorprostenol on day 7 and with 100µg lecirelin two days later. Furthermore, HD-group received the same treatment as FD-cows but the dose of lecirelin was reduced to 50µg at both times of GnRH administration. Ovarian structures were monitored by ultrasound with a 5-MHZ linear transrectal probe on days - 1 to 12. The ovarian responses of the various groups to first GnRH administration showed (0%, 40% and 60%) ovulation rate for C, HD and FD groups respectively in Bunaji breeds while in Friesian × Bunaji, it was (0%, 60%, 60%). Following second GnRH administration ovulation rate for Bunaji was (20%, 60%, and 60%) for Control, HD and FD-groups, respectively, while for Friesian × Bunaji cows it was (20%, 60%, and 80%). There was no significant difference (p > 0.05) in the days of new follicular wave emergence following the first GnRH administration. It was concluded that 50µg Lecirelin reduced the cost of drug without affecting the efficiency of Ovsynch protocol.

Effect of 200 µg of gonadorelin at the first gonadotropin-releasing hormone of the Resynch-25 on ovarian dynamics and fertility in lactating Holstein cows

Our objective was to determine the effect of a 200-µg dose of GnRH 25 d after previous artificial insemination (AI) in a Resynch-25 resynchronization program on ovulatory response, circulating progesterone (P4) concentrations before and after treatment, and pregnancy per AI (P/AI) compared with a 100-µg dose in lactating Holstein cows. Experimental d 0 was considered the day of the previous AI. Lactating dairy cows (n = 3,240) with an average of 126 d in milk (DIM) and between 1 and 6 services were randomly assigned to receive 100 µg or 200 µg of GnRH on d 25 (GnRH25). On d 32 after AI, cows diagnosed nonpregnant with the presence of a corpus luteum (CL) detected by ultrasound (n = 1,249) received PGF2α treatments on d 32 and 33, followed by a GnRH 32 h later and AI 16 h after this last GnRH. Blood samples were collected on d 25, 32, and 34 to evaluate serum P4 concentrations. Transrectal ultrasonographic examination was performed on d 25 and 27 to assess ovulatory response to GnRH25. Cows were checked for pregnancy on d 32, 46, and 88 after AI. The larger dose of GnRH increased the overall proportion of cows that ovulated to the GnRH25 (25.0% for the 100-µg dose vs. 32.5% for the 200-µg dose). However, when cows were evaluated separately according to the pregnancy status on d 32 after AI, we found no treatment effect within cows pregnant and nonpregnant. Even though treatment increased the proportion of cows with serum P4 ≤0.42 ng/mL at the last GnRH treatment (G2; 86.2% for the 100-µg dose vs. 93.0% for the 200-µg dose), it did not affect P/AI on d 32, 46, and 88. Furthermore, a greater proportion of cows without a functional CL at GnRH25 had circulating P4 concentrations ≥1.00 ng/mL on d 32 and lower than 0.42 ng/mL on G2. These cows also had a greater P/AI on d 32, 46, and 88. In summary, the larger dose of GnRH on d 25 after AI did not increase the ovulatory response in nonpregnant cows and P/AI on d 32, 46, and 88 after AI after the Resynch-25 program. Additionally, nonpregnant cows without a functional CL at GnRH25 were better synchronized after the Resynch-25 protocol and had greater P/AI on d 32, 46, and 88 after timed-AI.

GnRH analogs induce a LH peak and increase pregnancy per timed-AI in ewes

To date, there have been no studies testing the capacity of GnRH analogs and respective doses to induce a LH peak in sheep. In this sense, the present study aimed to evaluate the capacity of different synthetic forms and doses of GnRH in inducing LH release in sheep, and the effect of GnRH administration at timed artificial insemination (TAI) on pregnancy per timed-AI. In experiment 1, ewes (n = 40) received an intravaginal device (IVD) of medroxyprogesterone acetate (MPA; 60 mg) for 7 d and prostaglandin F2α analog on Day 5. On Day 7, the ewes were allocated randomly into one of eight groups (n = 5/group), which received a GnRH analog at a specific dose, as follows: lecirelin (12.5 or 25 μg), gonadorelin (50 or 100 μg), buserelin acetate (4.2 or 8.4 μg), or deslorelin (375 or 750 μg). Blood samples for LH determination were obtained at 0, 2, 4, and 6 h after GnRH and the IVDs were removed after the last blood collection. The maximal LH concentration induced by gonadorelin at doses of 50 μg and 100 μg (12.0 ± 2.4 ng/mL and 28.6 ± 7.1 ng/mL, respectively) was lower (P < 0.05) than serum LH induced by 8.4 μg of buserelin (78.9 ± 12.9 ng/mL), 375 μg and 750 μg of deslorelin (75.6 ± 7.4 ng/mL and 72.1 ± 10.6 ng/mL, respectively) and 12.5 μg and 25 μg of lecirelin (73.3 ± 17.8 ng/mL and 61.6 ± 5.9 ng/mL, respectively). However, the maximal LH concentration induced by 4.2 μg of buserelin (49.4 ± 5.9 ng/mL) was similar (P > 0.05) to the 100 μg of gonadorelin. The total release of LH (area under the curve – AUC) after treatment with 50 μg of gonadorelin (31.7 ± 5.9 ng h/mL) was lower (P < 0.05) than after other agonists. In a second experiment, 330 ewes were treated with IVD containing MPA for 7 d. Simultaneously with IVD removal, 250 μg of cloprostenol and 200 IU of eCG were administered. Then, ewes were assigned randomly to either no further treatment (control); or to receive 4.2 μg of buserelin acetate (GnRH group) at cervical TAI, which was performed with fresh semen 54 h after IVD withdrawal in all the animals. Higher pregnancy per timed-AI was observed for GnRH (50.3 %) compared to control (40.7 %). We conclude that buserelin acetate (8.4 μg), lecirelin (12.5 and 25 μg) and deslorelin (375 and 750 μg) induced a greater stimulatory effect on LH secretion than gonadorelin treatment. Furthermore, buserelin acetate treatment at TAI increased pregnancy per timed-AI in ewes previously treated with MPA and eCG.

Influence of GnRH analog and dose on LH release and ovulatory response in Bos indicus heifers and cows on day seven of the estrous cycle

This study evaluated the influence of GnRH analogs (gonadorelin vs. buserelin) and doses (single vs. double) on LH release and ovulatory response in Bos indicus (Nelore) females on Day 7 of the estrous cycle. Cycling heifers and non-lactating cows were pre-synchronized: Day −10: progesterone (P4) implant insertion plus 2 mg of estradiol benzoate; Day −2: implant removal and 0.53 mg of cloprostenol sodium (PGF); Day 0: 25 μg of lecirelin (GnRH). Over four replicates, heifers (n = 57) and cows (n = 53) that ovulated to the GnRH treatment on Day 0, having a visible corpus luteum (CL) and a dominant follicle (DF) ≥ 8.5 mm, were allocated to receive the following GnRH treatments on Day 7: G-Single (100 μg of gonadorelin); G-Double (200 μg of gonadorelin); B-Single (10 μg of buserelin); and B-Double (20 μg of buserelin). At GnRH treatment, a P4 implant was inserted in heifers (0.5 g) and cows (1 g). Ultrasound examinations were done on Days −10, −2, 0, 2, 7, 9, 12, and 14 to evaluate DF diameter, ovulation and presence of CL. Blood samples were collected on Day 7 at 0, 2, and 4 h from GnRH treatment, to evaluate circulating P4 and LH concentrations. On Day 12, the P4 implant was removed, females received two PGF treatments (24 h apart), and 2 d later, 25 μg of GnRH was given to start the next replicate. In both heifers and cows, P4 concentrations were elevated on Day 7, and similar among groups (3.9 and 4.2 ng/mL, respectively). In heifers, buserelin induced greater LH peak (9.5 vs. 2.6 ng/mL; P < 0.01) and greater ovulation (88.9 [24/27] vs. 16.7% [5/30]; P < 0.01) than gonadorelin treatments, regardless of the dose. Similarly, in cows, buserelin induced greater LH peak than gonadorelin (9.9 vs. 4.9 ng/mL; P < 0.01). However, ovulation was only increased in cows from the B-Double group (90.9% [10/11]), whereas in the other groups the ovulatory response was similar (35.7% [15/42]). Regardless of treatment, heifers had similar P4 concentrations (P = 0.22), but smaller DF (P < 0.01) than cows on Day 7. Only in G-Double group the LH peak was lower (P = 0.05) in heifers than in cows, with no difference within other groups. In heifers, but not in cows, the single dose of buserelin resulted in high ovulatory response, equivalent to that produced by the double dose. In conclusion, in Bos indicus heifers and cows on Day 7 of the cycle, with elevated P4 concentrations, buserelin induced greater LH release and ovulatory response than gonadorelin treatments. Double doses increased the LH release, however, only resulted in greater ovulation in females treated with buserelin. Finally, although circulating P4 concentrations did not differ between parities, heifers were more likely to ovulate in response to a GnRH-induced LH peak than cows.

Seasonal distribution of repeat breeder cows and evaluation of modified protocols for post AI treatment during summer.

An important problem of dairy industry worldwide is repeat breeder cows (RB). In this study, one farm in Northern Greece was chosen on the basis of subfertility. First, the available reproductive data of the previous year were evaluated; then, the farmer was advised to use the most common treatments for RB [GnRH with the third artificial insemination (AI+GnRH) or ovsynch in cows found empty after the second AI], and their efficacy was monitored throughout the year. Cows (n = 147) 2.5 to 4.5 years old were included. During the next year, post AI treatments (meta-ovsynch and meta-AI) were used during summer; GnRH (100 μg of gonadorelin) alone or in combination with meloxicam (0.5 mg/kg BW) was used during summer. Meta-ovsynch protocols were administered to 29 cows detected as non-pregnant after 3 AIs; cows were divided randomly into 3 meta-ovsynch (OS) groups: group OS (controls, n = 10), standard ovsynch protocol; group OS+GnRH (n = 10), OS plus GnRH 10 days after AI; and group OS+GnRH+NSAID (n = 9), OS plus GnRH 10 days after AI plus meloxicam 15 days after AI. Meta-AI protocols were tested in 27 RB cows; cows were divided randomly into 3 AI groups: GnRH (n = 9), 1 dose of GnRH with AI; GnRH-GnRH (n = 9), two doses of GnRH, one with AI and another 10 days later; and GnRH-GnRH-NSAID (n = 9), two doses of GnRH as in GnRH-GnRH group and one dose of meloxicam 15 days after AI. Pregnancy diagnosis was performed by ultrasound 38 days after AI. During the 1st year of evaluation, 53.79% of cows had received ≥ 3 AIs; the highest percentage (38.48%) of RB cows was recorded during autumn. After treatment for RB, the lowest (P < 0.05) pregnancy rate (PR) was recorded in August (18.18%) compared to January (75.0%), May (53.33%), and December (50.0%, P < 0.1). The efficacy of ovsynch during winter was significantly higher compared to all the other seasons. The percentage of cows with increased estrous cycle duration (24-37 days) after RB treatment and AI was the highest (P < 0.05) in spring and summer after AI+GnRH and the lowest (P < 0.05) during winter after ovsynch. Concerning the post AI treatments during summer, significantly higher pregnancy rate was recorded in the OS+GnRH+NSAID group (55.55%) compared to OS+GnRH (10%) and OS (10%) groups. Pregnancy rates did not differ among AI groups. It seems that OS+GnRH+NSAID is a promising protocol for RB cows during summer although further research is needed to support the present results.

Effect of increasing GnRH dose during Double- Ovsynch on fertility of lactating dairy cows

The rate of ovulation to the first GnRH treatment of Ovsynch-type protocols is key to achieve excellent fertility. In cows syn­chronized with the Double-Ovsynch protocol (DO), only around half of the cows ovulate to the third GnRH injection (first GnRH of the Breeding-Ovsynch portion of Double-Ovsynch). Increas­ing the dose of GnRH at this time has been proven to improve ovulatory response, reaching up to 67% of ovulation rate. Our objective was to determine whether increasing the dose of the third GnRH of DO could improve the reproductive outcomes at first service.

A high dose of initial GnRH increased ovulatory response and fertility in Holstein heifers subjected to a progesterone based 5-d CO-Synch protocol

The objectives of this study were to investigate the effect of presynchronization or dose of GnRH on ovulatory response to initial GnRH, estrus expression and reproductive outcomes in Holstein heifers subjected to a progesterone based 5-d CO-Synch protocol. Heifers were fitted with a collar-mounted automated activity monitoring system on Day −5 and were assigned randomly to one of three groups: 1) G100 (n = 111), a 5-d CO-Synch plus PRID protocol with administration of 100 μg of GnRH at the time of PRID insertion (Day 0), 500 μg of cloprostenol (PGF) at the time of PRID removal (Day 5) and again 24 h later (Day 6); 2) G200 (n = 112), same as G100 except 200 μg GnRH was administered on Day 0; 3) P10 (n = 111), PRID + PGF on Day −5 followed by a 5 d CO-Synch with administration of 100 μg of GnRH on Day 0, PGF at the time of PRID removal (Day 5) and again 24 h later (Day 6). Approximately 72 h after PRID removal (Day 8), all heifers were timed-inseminated (TAI) and concurrently 100 μg of GnRH was administered to those not exhibiting estrus. All inseminations were done by one technician using either sex-sorted (n = 265) or conventional (n = 69) frozen-thawed semen. Transrectal ultrasonography was done to determine ovarian cyclicity and normalcy of the reproductive tract, ovarian dynamics and pregnancy. All heifers were cyclic and ovulatory response to initial GnRH was greater (P < 0.01) in G200 (51.8%) and P10 (47.7%) compared to G100 (27.9%). Estrus expression rate tended to be greater (P = 0.08) in G100 (93.7%) compared to G200 (85.7%) and intermediate in P10 (89.2%). Expression of estrus was associated positively with P/AI at 45 d post-TAI (P < 0.01; 70.2 vs. 31.4% for heifers expressing or not expressing estrus). Heifers in the G200 group had greater P/AI at 30 (P < 0.01) and 45 (P = 0.01) d post-TAI (79.5 and 75.9%, respectively) compared to those in G100 (63.1 and 60.4%) or P10 (64.0 and 62.2%) groups. Pregnancy loss did not differ among treatment groups (overall 3.9%). Results indicate that increasing the dose of the initial GnRH from 100 to 200 μg resulted in increased ovulatory response and improved P/AI in Holstein heifers subjected to a progesterone based 5-d CO-Synch protocol. Although heifers presynchronized with a combination of PRID and PGF had an increased ovulatory response to the initial GnRH, P/AI did not differ from the standard progesterone based 5-d CO-Synch protocol.

Effect of Age and Different Doses of GnRH and PGF2α Analogue on Oesturs Synchronization and Conception Rate of Crossbreed Heifers

Forty-eight crossbreed heifers were artificially inseminated within 10-20 hours after standing heat to evaluate the effects of different doses of hormones and age on reproductive performance synchronized with GnRH and PGF2α. On day 90 after artificial insemination, the conception rate was confirmed by rectal palpation. There were significant differences (<I>P</I><0.05) in oesturs response in maximum doses (1.5 ml GnRH used in group III) of the hormone-treated group. The conception rate was significantly higher (<I>P</I><0.05) in the highest treatment group (1.5 ml, 66.67%) than in low treatment groups (1 ml and 1.3 ml; 42.85% and 44.44%; respectively) in morning synchronization protocol (83.33%). The effect of different doses of the hormone on conception rates was statistical significance on the age of crossbreed heifers (<I>P</I><0.05), time of initiation of ovsynch (<I>P</I><0.05), time of insemination (<I>P</I><0.05), semen placement (<I>P</I><0.05), body condition score (<I>P</I><0.05), retrieve to natural oesturs and subsequent pregnancy rate (<I>P</I><0.05). On the other hand, there was no significant (<I>P</I>>0.05) effect on conception rate by the onset of oesturs and duration of oesturs. The highest oesturs rate and conception rate was observed at 75.00% and 66.67%; respectively by administration of maximum doses of the hormone of body condition score (3) 69.23% of crossbreed heifer. When 1.5 ml GnRH was used in group III, the conception rate was observed higher at 25-30 months of age (77.78%) which were inseminated in the site of the deep cervix (77.77%) with frozen-thaw semen by experience inseminator at 10-14 hours (75%) after the onset of oesturs and naturally retrieve of oesturs on conception rate (75%). It was concluded that the age of the heifers, doses of the hormone, Body Condition Score (BCS), time of initiation of synchronization protocol, time of AI, semen placement and retrieve to oesturs naturally were the most important factors to get maximum oesturs response and conception rate of crossbreed heifers. So, it may be suggested that to achieve the desired rate of oesturs and conception, the farmers should inseminate their crossbreed heifers (BCS, 3 out of 5) with maximum doses of hormone in the deep cervix by technically sound and skilled inseminator at 10-14 hours after onset of oesturs in morning synchronization protocol. GnRH and PGF2α analogs could successfully induce oesturs response and improve the fertility of a dairy herd. Therefore, ovsynch protocol for crossbreed heifers is needed for further work involving a large number of animals for a definite conclusion.

Additional single dose GnRH agonist during luteal phase support may improve live birth rate in GnRHa-HRT frozen–thawed embryo transfer cycle: a retrospective cohort study

BackgroundGnRH agonist (GnRHa) has been reported to have direct effects and functional roles in the endometrium and embryos. Several meta-analyses have shown that GnRHa administration in the luteal phase improved the live birth rate or pregnancy rate in both fresh and frozen embryo transfer (FET) cycles. The aim of this study was to investigate whether luteal GnRHa administration could also improve in vitro fertilization (IVF) outcomes in patients undergoing hormone replacement therapy (HRT) cycles with GnRHa suppression.MethodsThe retrospective cohort study included a total of 350 patients undergoing GnRHa-HRT FET cycles. The study group included 179 patients receiving an additional single dose of GnRHa in the luteal phase following embryo transfer. A total of 171 patients in the control group did not receive luteal GnRHa. The baseline and cycle characteristics and reproductive outcomes were compared between the two groups.ResultsBaseline and cycle characteristics were similar between the two groups, except lower AMH levels were found in the luteal GnRHa group than in the control group. The luteal GnRHa group had a significantly higher ongoing pregnancy rate and live birth rate than the control group. The multivariate analysis revealed that luteal GnRHa administration was positively associated with ongoing pregnancy (OR 2.04, 95% CI 1.20–3.47, P = 0.008) and live birth (OR 2.03, 95% CI 1.20–3.45, P = 0.009). When the subgroup of patients with recurrent implantation failure was analyzed, the multivariate analysis also showed that luteal GnRHa administration had beneficial effects on ongoing pregnancy (OR 4.55, 95% CI 1.69–12.30, P = 0.003) and live birth (OR 4.30, 95% CI 1.59–11.65, P = 0.004).ConclusionsOur data suggest that the addition of one luteal dose of GnRHa may improve the live birth rate in patients undergoing the GnRHa-HRT protocol.

GnRH dose at initiation of a 5-day CO-Synch + P4 for fixed time artificial insemination in suckled beef cows

The objective of the present study was to evaluate the effect of GnRH dose administered at initiation (GnRH-1) of a 5-day CO-Synch + P4 protocol on ovulatory response, expression of estrus, and fertility in suckled beef cows. Suckled beef cows (n = 1101) at four locations were randomized to receive either 100 or 200 µg of gonadorelin acetate at initiation (D-8) of a 5-day CO-Synch + P4 protocol concurrently with insertion of an intravaginal progesterone (P4) device. On D-3 the P4 device was removed, two doses of prostaglandin F2α were administered concurrently and a patch was applied to evaluate expression of estrus. Artificial insemination was performed 72 h after P4 device removal (D0) simultaneously with the administration of 100 µg of gonadorelin acetate (GnRH-2). Increasing GnRH dose at initiation of a 5-day CO-Synch + P4 did not enhance ovulatory response (P = 0.57) to GnRH-1, expression of estrus (P = 0.79), nor pregnancies per AI (P/AI; P = 0.91). Both follicle size (quadratic) and circulating P4 (linear) affected (P < 0.01) ovulatory response to GnRH-1 independent of dose. Cows that had ovulation to GnRH-1 had smaller (P < 0.001) follicle size on D-3 and reduced (P = 0.05) expression of estrus compared to cows that did not have ovulation to GnRH-1, however, P/AI did not differ (P = 0.75). In conclusion, increasing the dose of GnRH-1 in the 5-day CO-Synch + P4 protocol did not enhance ovulatory response, expression of estrus, or P/AI in suckled beef cows.

Administration of GnRH at day 20 of AI and embryonic losses in synchronized crossbred buffalo.

Following the application of different artificial insemination and synchronization protocols, the synchronized buffaloes had a higher incidence of early embryonic or fetal death, thus impairing reproductive performance. Therefore, there is a need to devise a synchronizing program that can improve conception, allow early pregnancy diagnosis, reduce early embryonic losses, and provide an early clue for pregnancy diagnosis and establishment. The present study aimed (1) to determine the effect of administration of different GnRH doses at day 20 of artificial insemination (AI) on the reproductive performance of buffaloes and (2) to observe the influence of synchronization protocol, parity, age, milk production, and body condition score (BCS) on early embryonic loss and progesterone (P4) levels in crossbred buffaloes. Crossbred buffaloes (n = 101) were synchronized using the GPGMH protocol. At day 20 of AI, the synchronized buffaloes were randomly divided into four groups and administrated GnRH doses (0, 100, 150, and 200 μg). The buffaloes were monitored for ovarian dynamics, P4 level, non-return rate, embryonic/fetal losses, and pregnancy rates. The previously synchronized buffaloes were also classified for synchronization protocol (with or without GnRH), parity (nulli- or multiparous), milk production (high or low), BCS (low, medium, or good) or age (>3 or < 3 years) groups for observing the embryonic loss and P4 level variations. The results indicated no difference (P > 0.05) in CL size, P4 level, pregnancy rate and embryo/fetal losses across the treatment groups at different observation periods. There was a high (P < 0.05) incidence of early embryonic mortality in aged, multiparous, low BCS and low milk-producing buffaloes treated without GnRH. The data suggest that GnRH 200 μg at day 20 of AI improves embryo survival and pregnancy maintenance in crossbred buffaloes.

GnRH administration after estrus induction protocol decreases the pregnancy rate of recipient ewes following transfer of frozen-thawed embryos

The objective of this study was to investigate the effects of GnRH on the pregnancy rate and the embryo survival rate of recipient ewes following embryo transfer. Estrus was synchronized in 83 nulliparous Huyang ewes using intravaginal sponges impregnated with 45 mg flurogestone acetate. The sponge was left in the vagina for 12 days followed with an injection of 330 IU of eCG at sponge removal. The treatment group (n = 34) was subjected 48 h after sponge removal to intramuscular administration with 16 μg of the GnRH agonist triptorelin and the control group (n = 49) with 1 mL of saline solution. Embryo transfer was performed by laparoscopy on day 8 after sponge removal, which transferred frozen-thawed embryos of Suffolk ewes directly to the anterior third of the corpus luteum ipsilateral uterine horn of the recipient ewe.Each recipient with at least one normal corpus luteum received one grade I embryo. The proportion of ewes with at least one normal corpus luteum in the control group was significantly lower compared to the treatment group (73.5 % vs 91.2 %, P < 0.05). In total, 62 embryos were transferred into 62 ewes and 29 lambs were born. The pregnancy rate (59.4 % vs 33.3 %, P < 0.05) and the embryo survival rate (56.3 % vs 30.0 %, P < 0.05) in the control group were significantly higher compared to the treatment group. In conclusion, a single dose of GnRH administered 48 h after sponge removal significantly decreased the pregnancy rate and the embryo survival rate of recipient ewes following transfer of frozen-thawed embryos.

RTOG/NRG 1115 Quality of Life of Phase III Dose Escalated Radiation Therapy (RT) and Standard Androgen Deprivation Therapy (ADT) with GnRH Agonist vs. Dose Escalated RT and ADT with GnRH Agonist and Orteronel (TAK-700) for Men with High-Risk Prostate

<h3>Purpose/Objective(s)</h3> Quality of life (QOL) was assessed with the hypothesis that QOL and fatigue scores would not differ significantly between the ADT + RT (Arm A) and the experimental group receiving ADT + RT + oreteronel (Arm B). <h3>Materials/Methods</h3> In both arms, ADT with GnRH agonist was given for 24 mos, and dose escalated RT started 8-10 wks after initiation of ADT. In Arm B, oreteronel was given BID for 24 mos. QOL was measured with Expanded Prostate Cancer Index Composite (EPIC) and EQ-5D global QOL assessment. EPIC has 4 domains: bowel, urinary, sexual, and hormonal. EQ-5D index score was calculated using health states obtained from 5 dimensions, and a visual analog score (VAS). For EPIC, EQ-5D index and VAS, higher scores indicate better QOL. Fatigue was measured by the 7-item Patient-Reported Outcome Measurement Information System (PROMIS) short form. Total score is standardized into a T-score with mean of 50 and standard deviation of 10 with higher score representing more fatigue. Change scores, calculated as follow-up minus baseline, were compared between arms. Longitudinal analysis using repeated measures mixed effects models was conducted (prior to ADT [baseline], one wk prior to starting RT, last wk of RT, and 1 and 2.5 yrs after initiation of therapy). <h3>Results</h3> Of 231 eligible patients, 196 consented to QOL, 102 on Arm A and 94 on Arm B. Compliance prior to start of RT and end of RT was 83%. At 1 and 2.5 yrs, 80% and 62% of pts, respectively, completed the EPIC. There were no differences between any EPIC domain between arms from the start of RT through the end of follow-up. Men on oreteronel had a significantly greater decline in bowel score prior to starting RT then control patients (-6.12, 95% confidence interval [CI]: -9.24, -3.01 vs. -1.93, 95% CI: -4.48, 0.63, respectively, p=0.038). Arm B patients also had a statistically significant and clinically meaningful worse change in urinary score vs control from baseline to pre-RT (-2.33, 95% CI: -5.02, 0.36 vs. 1.38, 95% CI: -1.07, 3.83, respectively, p=0.043). No other timepoints were significant. The only sig. between arm difference in EPIC sexual and hormonal scores was also at pre-RT in favor of Arm A over Arm B; p=0.024 and p=0.0024 respectively). Fatigue was also greater in the oreteronel patients prior to starting RT (3.81, 95% CI: 1.88, 5.74 vs. 1.18, 95% CI: -0.23, 2.60, p=0.028). <h3>Conclusion</h3> The addition of oreteronel to RT and ADT resulted in greater declines in QOL prior to the start of RT but did not result in significant differences at any other time points. Although oreteronel development has been halted, the QOL results are encouraging for other drugs in this class that remain under investigation. In ongoing prospective trials, QOL impacts should be measured in conjunction with changes in clinical outcome and survival. This project was supported by grants UG1CA189867, U10CA180868, U10CA180822 from the National Cancer Institute and Takeda Pharmaceutical.

Clinical practice guidelines for endometriosis in Japan (The 3rd edition).

Clinical practice guidelines for endometriosis in Japan (The 3rd edition).

EFECTO DE LA EXPRESIÓN DE CELOS Y LA ADICIÓN DE GnRH SOBRE LA TASA DE PREÑEZ EN VACAS HOLSTEIN EN LACTANCIA SINCRONIZADAS CON ESTRADIOL Y DISPOSITIVOS CON PROGESTERONA

The aim of this investigation was to evaluate the effect of the addition of GnRH at the beginning and end of a treatment with progesterone-releasing devices (P 4 ) and estradiol (E2) and the expression of estrus on pregnancy rates (PR) of lactating dairy cows inseminated at fixed time (FTAI). The estrus synchronization treatment consisted on the insertion of a P 4 device for 8 days and the administration of estradiol benzoate (EB) on the day of insertion and estradiol cypionate (ECP) at the time of device removal to induce ovulation. Experiment 1 was designed to determine whether the addition of GnRH at the start of the protocol improved the PR and if the division of the time of artificial insemination (AI) improved PR. The addition of GnRH on Day 0 did not improve PR (44% vs 40%) but the AI of cows showing estrus at 48 h and the administration of GnRH at 48 h and AI at 60 h of those not showing estrus resulted in higher PR than those cows that were FTAI at 48 h, regardless of estrus expression (53% vs 31%; P &lt;0.01). Experiment 2 was designed to study follicular dynamics and assess whether the PR varies using different times of AI (48 h vs 60 h), according to the expression of estrus. The division of AI and adding GnRH at 48 h decreased the dispersion in the interval between AI and ovulation. There was an interaction (P&lt;0.05) between the time of AI and expression of estrus. Pregnancy rates were higher in cows in estrus at 48 h that were AI at that time (47.8%) and those that were not in heat at 48 h and were AI at 60 h (53.4%) than those who were not in estrus at 48 h and were FTAI at that time (19.4%) and those that were in estrus at 48 h and were FTAI at 60 h (29.7%). In Experiment 3 PR was evaluated based on the addition or not of GnRH to cows not showing estrus at 48 h. Pregnancy rate was higher (P&lt;0.05) in cows that were not in estrus at 48 h, that received GnRH at that time and were AI at 60 h than in cows not showing estrus and 48 h that were also AI at 60 h but without GnRH (56.0% vs 39.8%). Experiment 4 evaluated factors that may affect PR in cows treated with the protocol developed in this experiment. It was found that the heat stress of January, a body condition score &lt;2.75 and the presence of only small follicles (&lt;10 mm and without CL) adversely affect PR. In conclusion, the results of this series of experiments confirm the hypothesis that the inclusion of a dose of GnRH and the modification of the time of AI increase PR in lactating dairy cows treated with P 4 devices and estradiol that does not express estrus at the time of FTAI.

Maximizing the reproductive performances of anestrus dairy buffalo cows using GnRH analogue-loaded chitosan nanoparticles during the low breeding season

The present study was designed to evaluate the efficiency of GnRH-loaded chitosan-TPP nanoparticles (GnRH-CsNPs) to improve the reproductive performance of anestrus buffaloes during the summer. Egyptian buffaloes (n = 50) were synchronized for estrus either with the ovsynch protocol (OVSs, n = 20) or with the modified ovsynch protocol (OVSm, n = 30) using GnRH-CsNPs. Sera samples were collected on days 0, 7, and 10 (insemination day); and days15 and 30 post insemination for estradiol (E2) and progesterone (P4) determination. The follicles were monitored on day 0 and day 10. CLs diameter and pregnancy diagnosis were scanned on day 30 post insemination. Using a half dose of GnRH as GnRH-CsNPs in the OVSm improved (P < 0.05) the number of total and large follicles, and the total surface area of subordinate and large follicles compared to the OVSs protocol. The OVSm increased (P < 0.05) the largest follicles diameter on day 10 and CLs diameter on day 30 post insemination compared to the OVSs protocol. E2 concentration was greater (P < 0.05) on insemination day, and P4 concentrations were higher (P < 0.05) on days 15 and 30 post insemination in the OVSm than in the OVSs. The estrus induction rate was 80 % higher (P < 0.05) in the OVSm and cows exhibited estrus within 17.54 h earlier than the OVSs (50 % within 42 h), respectively. The conception rate increased in OVSm compared to OVSs (75 vs. 40 %, respectively). In conclusion, nanofabrication of GnRH allowed to reduce hormonal dose to 50 % without any adverse effects on fertility, and improved ovarian activity and reproductive performance of anestrus buffaloes during the low breeding season.