Effect of different doses of equine chorionic gonadotropin on follicular and luteal dynamics and P/AI of high-producing Holstein cows

Ferreira, Roberta Machado; Ayres, H.; Sales, J. N. S.; Souza, A. H.; Rodrigues, Carlos Alberto; Baruselli, Pietro Sampaio

doi:10.1016/j.anireprosci.2013.04.014

Cited by 23 publications

(15 citation statements)

References 39 publications

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“…Whereas in B. indicus, the majority of studies has shown a positive effect of eCG on percentage of heifers or cows that ovulate at the end of the protocol, greater circulating P4 during the subsequent diestrus, and improved P/AI (Baruselli et al, 2004;Peres et al, 2009;Sá Filho et al, 2009Lemes et al, 2011;Sales et al, 2011), data in B. taurus are conflicting and, although some studies in beef cattle have shown improved ovulation rate and fertility by adding eCG to the FTAI protocol (Pessoa et al, 2016), several studies have shown no or little benefit of eCG, especially in lactating Holstein cows (Small et al, 2009;Souza et al, 2009;Ferreira et al, 2013;Pulley et al, 2013).…”

Section: Corpus Luteum Function Luteolysis and Growth And Ovulationmentioning

confidence: 99%

Endocrine and metabolic differences between Bos taurus and Bos indicus cows andimplications for reproductive management

Sartori

Monteiro

Wiltbank³

2016

Anim Reprod

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Based on the considerable differences in ovarian morphology and function, as well as circulating hormones and metabolites between Bos indicus (B. indicus) and Bos taurus (B. taurus), researchers are using this acquired knowledge to optimize protocols for fixed-time artificial insemination (FTAI), and production of in vivo derived embryos by multiple ovulation or by in vitro embryo production (IVP). In B. indicus, at the time of follicle deviation, the dominant follicle is smaller and acquires ovulatory capacity at a smaller diameter than B. taurus. Moreover, despite ovulating smaller follicles and having smaller corpora lutea (CL), circulating concentrations of estradiol (E2) and progesterone (P4) are greater in B. indicus than B. taurus. These physiological differences may be related to greater circulating cholesterol, insulin and IGF1 in B. indicus than in B. taurus. For both genetic groups there is a negative relationship between circulating P4 and ovulatory response to the first GnRH treatment of a fixed-time AI (FTAI) protocol. Moreover, despite lower clearance rates of steroid hormones in B. indicus than B. taurus, the dose of 2 mg estradiol benzoate seems to be the most effective either for Nelore (B. indicus beef), Angus (B. taurus beef), or Holstein (B. taurus dairy) cows at the initiation of an E2/P4-based FTAI protocol to optimize synchronization and pregnancy per AI (P/AI). Several studies have shown that only one recommended dose of PGF2α at a FTAI protocol may be insufficient for adequate luteolysis in B. indicus and B. taurus. When submitted to multiple ovulation and embryo transfer, B. indicus cows and heifers need less FSH than B. taurus to achieve superovulation. Moreover, IVP has been more successful in B. indicus than B. taurus due to greater antral follicle count and anti-mullerian hormone, and better oocyte quality.

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Section: Corpus Luteum Function Luteolysis and Growth And Ovulationmentioning

confidence: 99%

Endocrine and metabolic differences between Bos taurus and Bos indicus cows andimplications for reproductive management

Sartori

Monteiro

Wiltbank³

2016

Anim Reprod

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“…Similar effects were also reported in dairy cattle. Thus, after injection of 400 or 600 IU of eCG, the growth rate and diameter of the ovulatory follicle were, respectively, 3.9±0.6 mm/day and 14.5±1.1 mm, and 3.5±0.5 mm/day and 13.9±1.2 mm (Ferreira et al 2013). It does not appear that a reduction in the diameter of the ovulatory follicle is a determining factor for infertility (Sartori et al 2001;Perry et al 2005) as long as a minimal value close to 10 mm is observed (Martinez et al 1999;Sartori et al 2001).…”

Section: Discussionmentioning

confidence: 89%

“…Increasing the dose of eCG (from 400 to 600 IU) did not lead to significant differences in the interval between treatment and ovulation in Holstein cattle. This interval was, respectively, 82.9±2.2 h in cows in the control group and 78.5±2.3 h in cows treated with 400 IU and 70.8 h in cows treated with 600 IU (Ferreira et al 2013). The majority of ovulations observed took place within 72 to 96 h after removal of the CIDR®.…”

Section: Discussionmentioning

confidence: 94%

Preovulatory follicle diameter, growth rate and time of ovulation during induced oestrus using a CIDR® in trypanotolerant female Bos taurus N’Dama cattle

Okouyi

Drion

Hanzen

2015

Trop Anim Health Prod

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The aim of this study was to assess the dose (300 to 600 IU) effects of equine chorionic gonadotropin (eCG) on the preovulatory follicle diameter, growth rate and time of ovulation characterized by echography. The eCG was injected at the end (D 0 ) of the 7-day treatment with a controlled internal device release (CIDR®) and a PGF 2α being injected 2 days before the removal of the CIDR® (d −2 ). The 120 N'Dama female were distributed into five experimental groups. The control group (n=26) was treated with physiological saline at the removal of the CIDR®, while the animals in the four treated groups received, respectively, 300 IU (n=25), 400 IU (n=24), 500 IU (n=22) and 600 IU (n=23) of eCG. The diameter of the preovulatory follicle was significantly higher (P<0.05) in the animals treated with 300 IU (10.1±1.4 mm) than in untreated animals (9.3±1.2 mm). Follicle growth rate was significantly (P<0.05) higher in treated animals (1.0± 0.4 mm/day) than in the control group (0.9±0.4 mm/day). The average interval between the time of eCG injection and ovulation was similar in the non-treated (83.7±14.4 h) and treated animals (79.7±11.9). Treated animals showed a significant increase in the percentage of ovulation (94.7 % compared to 73.1 %) (P<0.01). Use of eCG contributed towards synchronising the time of ovulation between 72 to 96 h, which would facilitate the use of systematic insemination.

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“…Simplicity and efficiency are essential characteristics leading to broad application of these techniques. The exogenous control of luteal and follicular development facilitates the application of assisted reproductive technologies in cattle by offering the possibility of planning TAI programs without sacrificing the overall results (Pursley et al Progesterone (P4)-releasing devices plus oestradiol have been successfully used for TAI in Holstein cattle (Souza et al 2009;Vasconcelos et al 2011;Ferreira et al 2013). After P4 source removal, an ovulatory stimulus should result in synchronous ovulation and acceptable pregnancy rates to TAI.…”

Section: Introductionmentioning

confidence: 99%

Inducing ovulation with oestradiol cypionate allows flexibility in the timing of insemination and removes the need for gonadotrophin-releasing hormone in timed AI protocols for dairy cows

Ferreira

Ayres²,

Gimenes

et al. 2017

Reprod. Fertil. Dev.

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The effects of addition of gonadotrophin-releasing hormone (GnRH) to a progesterone plus oestradiol-based protocol and timing of insemination in Holstein cows treated for timed AI (TAI) were evaluated. Cows (n=481) received a progesterone device and 2mg oestradiol benzoate. After 8 days, the device was removed and 25mg dinoprost was administered. Cows were allocated to one of three (Study 1; n=57) or four (Study 2; n=424) groups, accordingly to ovulation inducer alone (Study 1; oestradiol cypionate (EC), GnRH or both) or ovulation inducer (EC alone or combined with GnRH) and timing of insemination (48 or 54h after device removal; Study 2). In Study 1, the diameter of the ovulatory follicle was greater for GnRH than EC. Oestrus and ovulation rates were similar regardless of ovulatory stimuli. However, time to ovulation was delayed when GnRH only was used. In Study 2, cows treated with GnRH or not had similar pregnancy per AI (P/AI) 30 days (41.5% vs 37.3%; P=0.28) and 60 days (35.9% vs 33.0%; P=0.61) after TAI. TAI 48 and 54h after device removal resulted similar P/AI at 30 days (40.3% vs 38.5%; P=0.63) and 60 days (33.8% vs 35.1%; P=0.72). Thus, adding GnRH at TAI does not improve pregnancy rates in dairy cows receiving EC. The flexibility of time to insemination enables TAI of a large number of cows using the same protocol and splitting the time of AI.

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Effect of different doses of equine chorionic gonadotropin on follicular and luteal dynamics and P/AI of high-producing Holstein cows

Cited by 23 publications

References 39 publications

Endocrine and metabolic differences between Bos taurus and Bos indicus cows andimplications for reproductive management

Endocrine and metabolic differences between Bos taurus and Bos indicus cows andimplications for reproductive management

Preovulatory follicle diameter, growth rate and time of ovulation during induced oestrus using a CIDR® in trypanotolerant female Bos taurus N’Dama cattle

Inducing ovulation with oestradiol cypionate allows flexibility in the timing of insemination and removes the need for gonadotrophin-releasing hormone in timed AI protocols for dairy cows

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