Academic literature on the topic 'Double Ovsynch'

This study evaluated the effect of resynchronization programs on pregnancies in dairy cows. Of 1,342 cows confirmed not pregnant after their first artificial insemination (AI), those with a corpus luteum (CL) were resynchronized using Ovsynch or PG-GnRH-Ovsynch and those without a CL were resynchronized using GnRH-Ovsynch or modified Double-Ovsynch. There were no differences (p > 0.05) in the pregnancies per AI either between the Ovsynch (31.3%) and PG-GnRH-Ovsynch (34.0%) or between the GnRH-Ovsynch (38.7%) and modified Double-Ovsynch (39.5%). In conclusion, Ovsynch and GnRH-Ovsynch programs could be preferred to resynchronize cows with and without a CL, respectively, from the perspective of reducing costs and labor.

Ovarian cysts are among the primary causes for poor reproduction efficiency and economic losses in dairy cattle farming. Material and metods: The studies were performed in 2015-2017 in three dairy cattle farms.In the experiment, 79 cows with follicular ovarian cysts were divided randomly into 3 groups. To the first group (n=33), a standard double Ovsynch was applied with 0.01 mg GnRH (Veterelin, Laboratorios Calier, Spain) on day 0, 150 µg PGF2α (D – Cloprosstenolsodium, Indupart, Vetpharma Animal Health, Spain) on day 7, 0.01 mg GnRH (Veterelin, Laboratorios Calier, Spain) on day 10, and after 7 days, Ovsynch (GnRH-PGF-GnRH). The cows from the second group (n=28) were submitted to double Ovsynch and additional progesterone treatment through placement of Controlled Internal Drug Release device (EAZI BREED CIDR Cattle insert, 1.38 g progesterone; Pfizer Animal Health, USA) for 7 days between the first GnRH at day 0 and prostaglandin on day 7. The control group comprised 18 untreated cows. Results: First-service conception rate in cows treated by double Ovsynch and vaginal inserts was higher 28.6% compared to that in standard double Ovsynch: 24.2%. Cumulative pregnancy percentage after applied treatments was 60.7% in double Ovsynch plus progesterone and 54.5% in standard double Ovsynch.

Abstract Successful reproduction of lactating dairy cattle, or in other words its reproductive performance is a limiting factor in the profit ratio of cattle breeding regarding market production. The aim of this research was to evaluate the success rate of synchronization protocols Ovsynch, Presynch/Ovsynch, and Double Ovsynch within the period of 24 months. The success rate of the 1st insemination, 2nd insemination, and after more than 2 inseminations was evaluated. The cattle were of Holstein Friesian breed with a milk yield of 10 200 kg. The animals were sorted into two categories – heifers (protocol Ovsynch) and primiparous, multiparous cows (protocols Presynch/Double Ovsynch). The research proved a 54 % success rate in the category of heifers after the 1st insemination. In the category of primiparous and multiparous cows was the success rate of 41 % after the 1st insemination, 39 % after the 2nd insemination, and 52 % after more than 2 inseminations for the Presynch/Ovsynch protocol. The success rate for Double Ovsynch protocol was 45 % after the 1st insemination, 42 % after the 2nd insemination and 51 % after more than 2 inseminations. The results for the given geographic region of Slovakia exceeded the average.

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.

The goal of this experiment was to compare the effectiveness of three popular synchronization protocols, viz. ovsynch, double prostaglandin (PGF2? /PG) injections, and MAP (Medroxyprogesterone acetate) sponges, in anestrous goats. Twenty one non pregnant multiparous anestrous goats with an average body condition score (BCS = 2.5) were selected. After the last PG injection, all the goats were exposed to three fertile bucks. They were observed to be in standing estrus. For further confirmation of copulation, a vaginal cytology test was performed for the presence of sperm inside the vaginal smear. Serum estradiol (E2) peaks were also estimated by using radioimmunoassay in estrus goats. MAP sponge efficiency with respect to estrus induction was found to be superior (57%) as compared to the rest (Ovsynch14 and PG 0%) (p< 0.05). Post PG standing estrus time in ovsynch and MAP groups was recorded as 48 h and 44 ± 12 h, respectively. The double PG group totally failed to show standing estrus. E2 peak levels ranging from 11-38 pg/ml in ovsynch and 10–25 pg/ml in the MAP group were observed in estrus goats. This study found the MAP sponge protocol most efficient for inducing estrus in anestrous goats.

SummaryObjective: The aim of this study was to monitor the ovarian response and conception rate following estrous synchronization using CIDR, Ovsynch and double prostaglandin F2α protocols in Egyptian buffalo heifers. Material and methods: A total of 80 cyclic buffalo heifers were divided into four equal groups: CIDR (intravaginal progesterone releasing device, EAZI-BREEDTM CIDR®), Ovsynch (GnRH, PGF2α, GnRH injections), PGF (double PGF2α doses) and control. Timed artificial insemination (TAI) was performed in all heifers. All animals were exa - mined using ultrasound and blood samples were collected for measurement of progesterone. Results: A new follicular wave occurred earlier in the Ovsynch and PGF groups than in the CIDR group (p < 0.05). The mean diameter of the ovulatory follicle was smaller in the CIDR group than in the Ovsynch and PGF groups (p < 0.05). The ovulation rate was 100% in the CIDR group, 75% in the Ovsynch group and 70% in the PGF group. In the control group a lower pregnancy rate (20%) was determined in than in the CIDR (35%), Ovsynch (40%) and PGF (35%) groups. Progesterone concentrations were numerically higher in pregnant heifers of the CIDR group but the difference was non-significantly compared to the Ovsynch, PGF and control groups (p > 0.05). Conclusion and clinical relevance: EAZIBREEDTM CIDR®, Ovsynch-based TAI and PGF protocols were effective in synchronizing oestrus and resulted in nearly similar pregnancy rates in Egyptian buffalo heifers.

This study was aimed to observe the effect of various synchronization protocols viz. Double PGF2α, Presynch-Ovsynch, Ovsynch and CIDR-Ovsynch on fertility in postpartum sub-estrus and true anestrous graded Murrah buffaloes under farm and field conditions and during breeding and low breeding seasons. Experimental period comprised from September 2017 to August 2019 (includes breeding and low breeding season)._Presynch_and Ovsynch protocol improved the conception and pregnancy rate in sub-estrus and true anestrus buffaloes during breeding and low breeding seasons under farm and field conditions.

The objective was to compare a pre-synchronization protocol by induction of a dominant follicle using a progesterone intravaginal device before an Ovsynch protocol (Presynch) with Double-Ovsynch in lactating dairy cows. Lactating Bos indicus × Bos taurus crossbred cows (n = 440) were randomly allocated to 1 of 2 treatments (all IM injections): (1) Double-Ov (n = 228): GnRH (Day –17), prostaglandin F2α (PGF2α) 7 days later (Day –10) and gonadotropin-releasing hormone (GnRH) 3 days later (Day –7) followed by an Ovsynch protocol 7 days later (GnRH on Day 0, PGF2α on Day 7, GnRH on Day 9); (2) Presynch (n = 212): insertion of a sustained release progesterone intravaginal device (Day –10), 10 days later (Day 0), an Ovsynch protocol was initiated with progesterone device withdrawal on Day 7. All cows were artificially inseminated 15 to 20 h after the second GnRH injection of the Ovsynch protocol and were pregnancy checked by ultrasonography 30 and 60 days later. On a subsample (n = 102), ultrasonography was performed on Days 0, 7, 9, and 24 of the experimental period. On another subsample (n = 42), blood samples for progesterone analysis were taken on Days 0, 7, and 24. There were no differences between pre-synchronization methods on synchronization parameters [presence of a follicle >12 mm on D0, Double-Ov 94.2% (49/52) and Presynch 92.0% (46/50); P = 0.66], follicular diameter on the 1st GnRH (Double-Ov 17.2 ± 0.7 mm and Presynch 18.6 ± 0.9 mm; P = 0.28), ovulation rate to the 1st GnRH [Double-Ov 86.3% (44/51) and Presynch 81.2% (39/48); P = 0.50], synchronization rate [Double-Ov 84.6% (44/52) and Presynch 86.0% (43/50); P = 0.84], follicular diameter on the 2nd GnRH (Double-Ov 17.5 ± 0.6 mm and Presynch 18.0 ± 0.5 mm; P = 0.48), ovulation rate to the 2nd GnRH [Double-Ov 90.9% (40/44) and Presynch 86.0% (37/43); P = 0.48] and CL diameter on Day 24 (Double-Ov 27.9 ± 0.7 mm and Presynch 29.4 ± 0.9 mm; P = 0.19). Corpus luteum presence on Day 0 was different (P = 0.03) between treatments [Double-Ov 57.7% (30/52) and Presynch 36.0% (18/50)]. Moreover, there was no difference (P = 0.85) between pregnancy rates on Day 30 [Double-Ov 39.0% (89/228) and Presynch 40.1% (85/212)] or Day 60 after AI [Double-Ov 34.8% (79/227) and Presynch 38.7% (82/212); P = 0.41] and gestational loss between 30 and 60 days after AI [Double-Ov 7.9% (7/88) and Presynch 3.5% (3/85); P = 0.13]. Proportion of cows with P4 <1 ng mL−1 on Day 0 was similar between treatments [Double-Ov 13.6% (3/22) v. Presynch 5.0% (1/20); P = 0.37]. Likewise, the proportion of cows with P4 >1 ng mL−1 on Day 7 [Double-Ov 77.3% (17/22) v. Presynch 95.0% (19/20); P = 0.14] and P4 concentration on Day 24 (Double-Ov 4.7 ± 0.6 v. P4-Ov 5.9 ± 0.9; P = 0.84) were similar between treatments. In conclusion, pre-synchronization by induction of follicular persistence using a sustained-release progesterone device before Ovsynch yielded similar results to the Double-Ovsynch protocol on follicular development and regression patterns and on the fertility of lactating dairy cows.

AbstractThe aim was to evaluate the effect of presynchronization with GnRH and PGF2α prior to Ovsynch on ovulatory response to first GnRH, diameter of largest follicle at TAI and pregnancy per AI (P/AI) in multiparous dairy cows during summer. Cows (n=1069) were randomly assigned to one of three timed-AI (TAI) protocols. The TAI protocols were: 1) Ovsynch (O; n=425), GnRH- 7d-PGF2α-56h-GnRH-16h-TAI), 2) double-Ovsynch (DO; n=302), GnRH-7d-PGF2α-3d-GnRH and Ovsynch was initiated 7 days later, and 3) G7G-Ovsynch (G7G; n=342), PGF2α-2d-GnRH and Ovsynch was initiated 7 days later. Ovarian examinations were performed by transrectal ultrasonography during Ovsynch to determine ovulatory response to first GnRH and diameter of largest follicle at TAI. Presynchronization increased ovulatory response after first GnRH of Ovsynch (P=0.001), which was greater in DO (74.0%) and G7G (76.0%) groups compared to O group (50.0%). Means (±SEM) diameter (mm) of largest follicle at TAI was smaller in cows presynchronized before Ovsynch (DO and G7G, overall 15.7±0.3) compared to that in cows subjected to a standard Ovsynch without presynchronization (18.5±0.42). P/AI at 32 d after Al was greater (P=0.001) in G7G (32.7%) and DO (31.1%) groups compared to Ovsynch (19.7%) group. Presynchronization prior to Ovsynch also affected P/AI at 60 and 150 d after AI (P<0.05). In conclusion, DO and G7G protocols resulted in greater ovulatory response to first GnRH, smaller ovulatory follicles and greater P/AI compared to a standard Ovsynch protocol. Therefore, TAI protocols that include a presynchronization with GnRH and PGF2α prior to Ovsynch should be used in multiparous cows during summer to achieve acceptable reproductive performance.

This study evaluated a new presynchronization method, the combination of Presynch and Ovsynch, prior to the implementation of the Ovsynch-fixed timed artificial insemination (OVS+FTAI) protocol, as modified by Double-Ovsynch (MDO) compared to the G6G protocol. Lactating Holstein cows in G6G (n=250) and MDO (n=270) treatment groups received the following treatments, respectively: PGF2α-2d-GnRH(pre-GnRH1)-6d-OVS+FTAI (GnRH(GnRH1)-7d-PGF2α(PG)-2d-GnRH(GnRH2)-18h-FTAI) and PGF2α-7d-GnRH-7d-PGF2α-3d-GnRH(pre-GnRH1)-7d-OVS+FTAI. On average, the days in milk (DIM) of cows at the time of GnRH1 injection was 75±0.08 (mean±SEM). Pregnancy was diagnosed 32-38 days after timed AI by ultrasonographic examination. Modified Double-Ovsynch increased the pregnancies per AI (P/AI) compared to the G6G protocol (P=0.01). For all cows (n=520), the pregnancy rate was higher in cows that had preovulatory follicles ≥16 mm in diameter at the time of GnRH2 injection, compared to the cows that had preovulatory follicles <16 mm in diameter at the same time (P=0.03). Modified Double-Ovsynch increased the mean (±SEM) serum concentration of progesterone (P4, ng/ml) at PG compared to the G6G protocol (P<0.01). Therefore, MDO increased the pregnancy rate of cows at the first postpartum insemination compared to the G6G protocol, due to the induction of ovulation in noncyclic cows, improvement of synchronization in ovarian events, improvement of the quality of the ovulatory follicles and oocytes, and provision of an appropriate intrauterine environment for embryonic development and survival.