Ovarian superstimulation after follicular wave synchronization with GnRH at two different stages of the estrous cycle in cattle

Kohram, Hamid; Twagiramungu, H.; Bousquet, D.; Durocher, J.; Guilbault, L.A.

doi:10.1016/s0093-691x(98)00065-x

Cited by 27 publications

(24 citation statements)

References 20 publications

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“…on Day 6) in nonpunctured animals. However, as observed previously, the puncture of all follicles ≥ 6 mm 4 days after GnRH treatment led to a significant increase in the number of recruitable follicles 2 days later (Kohram et al, 1998b) and on the day of initiation of superstimulation, this population of recruitable follicles no longer differed among Stage-groups. Generally, these results suggest that as a result of the combined use of GnRH and follicular puncture, the increased follicular turnover may lead to optimal ovarian conditions for superstimulation, i.e.…”

Section: Discussionsupporting

confidence: 79%

“…An earlier study (Kohram et al, 1998b) showed that the number of recruitable follicles 4 to 6 mm increased following the GnRH treatment and that this is indicative of the emergence of a new follicular wave within 3 to 4 days. This suggests that the rate of entry of recruited follicles during a GnRH-induced wave emergence varies according to the stage of the oestrous cycle when GnRH was given.…”

Section: Discussionmentioning

confidence: 91%

“…Based on this concept, a new approach has been developed (Kohram et al, 1998b) whereby GnRH is used at two different stages of the oestrous cycle to elicit the emergence of a follicular wave in a synchronous fashion in a group of cows and to expose a dominant follicle for puncture at a predictable time (i.e. 4 days after GnRH).…”

mentioning

confidence: 99%

“…4 days after GnRH). The effect of follicular synchronization with GnRH on hormonal and follicular response prior to and during superovulation was described (Kohram et al, 1998b) but its effect on embryo production has not been clearly defined yet. The objective of this study was to determine the effect of follicular synchronization with GnRH and of follicular puncture at any stage of the oestrous cycle prior to superovulation on the follicular status at the initiation of superstimulation and on in vivo production of bovine embryo.…”

mentioning

confidence: 99%

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Superovulation following follicular synchronization with GnRH at random stages of the oestrous cycle in heifers

Kohram¹,

Vahedi²,

Nasrollahi³

et al. 2011

CZECH J ANIM SCI

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ABSTRACT:The objective of this study was to develop a superovulatory program based on synchronization of follicular waves with GnRH which could be applied regardless of the stage of the oestrous cycle. 36 heifers were subjected to this experiment and GnRH (Cystorelin, 200 µg) was applied between Days 0 and 7 (n = 15), 8 and 12 (n = 8) or 13 and 20 (n = 13) of the oestrous cycle. Four days after GnRH treatment, all follicles ≥ 6 mm of heifers (n) were either punctured (n = 21) or left intact (n = 15). All heifers were superstimulated from Day 6 to Day 10 after GnRH treatment with 320 mg Folltropin-V. In parallel, 21 heifers were superstimulated in a conventional manner (Days 8 to 12) and were used as controls. The homogeneity of follicular inventories among Stage-groups occurred within 4 days of GnRH treatment for follicles ≥ 7 mm but only 2 days after follicular puncture for follicles 4 to 6 mm. In response to the follicular puncture, the mean number of follicles 4 to 6 mm increased in heifers of the punctured group (P < 0.01). Following the superstimulation, the follicular (P < 0.01) and ovulatory (P < 0.01) responses were higher in the punctured group than in the nonpunctured group. The in vivo production of transferable embryos in the punctured group was similar to that of the nonpunctured group but it was lower (P < 0.01) than in heifers of the control group. In conclusion, results from the present study indicate that regardless of the stage of the oestrous cycle, the homogeneity of follicular inventories following the follicular synchronization is obtained using GnRH treatment and follicular puncture. The in vivo production of embryos was severely compromised in the present study with heifers. Causes of such reduction in the in vivo production of embryos are still unknown.

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Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 91%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Superovulation following follicular synchronization with GnRH at random stages of the oestrous cycle in heifers

Kohram¹,

Vahedi²,

Nasrollahi³

et al. 2011

CZECH J ANIM SCI

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“…Ultrasonography has been used to study ovarian response to superovulation in cattle [46][47][48][49]. The influence of a dominant follicle on the superovulatory response has been reported in heifers and cows [50][51][52][53].…”

Section: Folliclesmentioning

confidence: 99%

Bovine Reproductive Ultrasonography: A Review

Ribadu

Nakao

1999

Journal of Reproduction and Development

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Abstract. The advent of ultrasonography over a decade ago has contributed tremendously in the field of bovine reproduction. Ultrasound imaging has shown that cattle exhibit 2 or 3 waves of follicular development during an estrous cycle. Ultrasonography allows monitoring of individual follicles as they grow and/or regress over time and patterns of follicular development can thus be determined with relative precision. Other important applications of ultrasonography in bovine reproduction includes; pregnancy diagnosis, fetal sex determination, folliculocenteses, diagnosis of abnormalities of the reproductive organs, monitoring of treatment of ovarian cysts, monitoring of postpartum genital resumption, ultrasound-guided centesis and male genital ultrasonography. Recent applications of ultrasonography in bovine reproduction includes doppler ultrasonography for genital blood flow and mammary ultrasonography. The use of ultrasonography is indispensable in most studies in which morphology (structure) and function are correlated. In this paper, the literature pertaining to the use of ultrasonography in bovine reproduction is reviewed. The applications and limitations of ultrasonography are highlighted. The non-invasive nature of ultrasonography makes it an excellent clinical and research tool in bovine reproduction.

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Relationships between the ovarian status and superovulatory responses in dairy cattle

Kohram

Poorhamdollah

2012

Animal Reproduction Science

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Ovarian superstimulation after follicular wave synchronization with GnRH at two different stages of the estrous cycle in cattle

Cited by 27 publications

References 20 publications

Superovulation following follicular synchronization with GnRH at random stages of the oestrous cycle in heifers

Superovulation following follicular synchronization with GnRH at random stages of the oestrous cycle in heifers

Bovine Reproductive Ultrasonography: A Review

Relationships between the ovarian status and superovulatory responses in dairy cattle

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