Inhibition of sperm transport and fertilization in superovulating ewes

Hawk, H. W.; Cooper, Bret; Conley, H.H.

doi:10.1016/0093-691x(87)90262-7

Cited by 37 publications

(13 citation statements)

References 18 publications

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“…It is well documented that oestrous synchronization and superovulation interferes with sperm transport in naturally mated ewes, which eventually result in impaired fertilization rate (Hawk et al 1987). For this reason, this study has improved the existing of laparoscopic intrauterine insemination techniques for application for the first time in Iraq in superovulated Awassi ewes.…”

Section: Discussionmentioning

confidence: 87%

A study on the effect of GnRH administration on the ovarian response and laparoscopic intrauterine insemination of Awassi ewes treated with eCG to induce superovulation

Azawi

Al-Mola

2011

Trop Anim Health Prod

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The effect of GnRH administration on superovulatory response of ewes treated with equine chorionic gonadotrophin (eCG) in breeding and nonbreeding seasons and the contribution of laparoscopic insemination to the improvement of fertilization and embryo recovery were investigated. Twenty-four nonpregnant Awassi ewes of 3-4 years of age were randomly allocated into two groups (n = 12). Each ewe was treated with a progesterone impregnated intravaginal sponge for 12 days. The following superovulation treatment was used: ewes of group 1 received 1,200 IU of eCG once as an intramuscular injection 48 h prior to sponge withdrawal; ewes of group 2 also received 1,200 IU of eCG once as an intramuscular injection, 48 h prior to sponge withdrawal and after 24 h of sponge removal. Ewes were injected with 80 μg of GnRH. Ewes of groups 1 and 2 were further subdivided into four equal groups (n = 6). Subgroups A and C (superovulated with eCG and eCG plus GnRH, respectively) were mated naturally at least two times with Awassi rams of proven fertility at 8-h intervals. Subgroups B and D (same as A and C) had intrauterine insemination at 44-46 h after sponge removal, under laparoscopic visualization of uterine horns, depositing 1 ml of diluted semen containing 100 × 10(6) motile sperm in the distal portion of each uterine horn. Ovarian response was assessed by determining the number of corpora lutea by laparoscopy at day 6 after mating. Embryo recovery was performed by using a semi-laparoscopic flushing procedure in both uterine horns. Results of the present study showed that ewes treated in breeding season with eCG plus GnRH has a higher number (P < 0.05) of corpora lutea than eCG alone as 7.33 ± 0.54 and 4.33 ± 0.39, respectively. There was no significant difference in the number of corpora lutea in nonbreeding season when ewes treated with eCG and eCG plus GnRH. The number of unovulated follicles was significantly higher (P < 0.05) in eCG treated ewes than in ewes treated with eCG plus GnRH, both in the breeding and nonbreeding seasons. The number of recovered embryos from ewes treated with eCG plus GnRH and eCG differ significantly (P < 0.05) as 4.32 ± 0.56 and 1.06 ± 0.26, respectively, in the breeding seasons. No significant difference was observed when these hormones used for superovulation in the nonbreeding season. A higher number of unfertilized ova (P < 0.05) was observed in ewes when naturally inseminated than in ewes inseminated using the intrauterine laparoscopic technique. Higher rate of embryo recovery (P < 0.05) was achieved when ewes were inseminated via intrauterine (4.66 ± 0.66) compared with ewes naturally mated (2.16 ± 0.74). The fertilization rate in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were 91.5% and 44.8%, respectively. Fertilization failure in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were 8.4% and 55.2%, respectively. It could be concluded that administration of GnRH 24 h after sponge removal increased ovulation rate of Awassi ...

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Section: Discussionmentioning

confidence: 87%

A study on the effect of GnRH administration on the ovarian response and laparoscopic intrauterine insemination of Awassi ewes treated with eCG to induce superovulation

Azawi

Al-Mola

2011

Trop Anim Health Prod

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“…Why this poor recovery rate of oocytes should be accompanied by zero fertilization which is in contrast with the high fertilization rates observed at the 48 and 60 h inseminations is not immediately apparent. Superovulation is known to impair both sperm transport and sperm viability (Hawk et al, 1987) following natural mating or cervical insemination; perhaps the same occurs following intrauterine insemi¬ nation early in the follicular phase of the oestrous cycle.…”

Section: Discussionmentioning

confidence: 98%

Fertilization and ovum recovery rates in superovulated ewes following cervical insemination or laparoscopic intrauterine insemination at different times after progestagen withdrawal and in one or both uterine horns

Robinson¹,

Wallace²,

Aitken³

1989

Reproduction

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In Exp. 1, 40 ewes were used in a 2 x 2 factorial design to investigate the effects of intrauterine versus cervical insemination and superovulation using pig FSH or PMSG and GnRH on egg recovery and fertilization rate. Cervical inseminations were carried out at 48 and 60 h (N = 20 ewes) and intrauterine insemination at 52 h (N = 20 ewes) after progestagen pessary withdrawal. Eggs were recovered on Day 3 of the oestrous cycle. Ovulation, egg recovery and fertilization rates were independent of the type of superovulatory hormone used. Fertilization rate was high irrespective of insemination site but intrauterine insemination at 52 h was associated with a significant (P less than 0.01) decrease in egg recovery of over 40% compared with cervically inseminated ewes. In Exp. 2 ewes were inseminated at 36 (N = 5), 48 (N = 6) or 60 (N = 6) h after pessary withdrawal to determine the optimum intrauterine insemination time to maximize both fertilization rate and egg recovery. Egg recovery per ewe flushed was 23, 59 and 67% after intrauterine insemination at 36, 48 and 60 h respectively. Correspondingly, 0, 85 and 100% of the eggs recovered were fertilized. The results of Exps 1 and 2 suggest that when intrauterine insemination occurs before or during ovulation it interferes with oocyte collection by the fimbria. In Exp. 3 egg recovery and fertilization rates were determined after cervical insemination at 48 and 60 h (N = 8) or intrauterine insemination at 48 (N = 9) or 60 (N = 8) h after progestagen withdrawal. Ewes in the last two groups were subdivided and inseminated unilaterally or bilaterally. Egg recovery was high after cervical insemination (95%) but only 36% of these eggs were fertilized. Unilateral intrauterine insemination was as effective as bilateral in ensuring high fertilization rates (100 versus 97%). Intrauterine insemination at 48 h compared with 60 h resulted in a significantly lower (P less than 0.05) percentage of eggs recovered (42 versus 90% respectively). However, reducing the degree of interference by adopting unilateral rather than bilateral insemination did not alleviate the detrimental effects of the 48-h insemination time on egg recovery. From these results we advocate the adoption of intrauterine insemination at 60 h after progestagen withdrawal to maximize fertilization rate and egg recovery in superovulated ewes.

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“…In cattle the number of AS depends on a number of factors as reviewed by Saacke et al [44][45][46][47], namely the breeding method (more AS following natural service), timing of breeding (more AS following 24 h versus 12 h and 0 h breeding after the first mount), embryos recovered from single versus multiple ovulating animals (more AS in single ovulating eggs) and finally the embryo quality (more AS in excellent/good embryos versus degenerate/unfertilized [47]). In ewes it has also been observed that superovulation will inhibit sperm transport [17] leading to fewer spermatozoa in all parts of the female genital tract and a lower number of AS in the zona pellucida. Again, natural breeding gave a significantly higher number of AS than artificial breeding (single ovulating 127 versus 23 or 17 per embryo).…”

Section: The Meetingmentioning

confidence: 99%

Rendez-vous in the oviduct: implications for superovulation and embryo transfer

Greve

Callesen²

2001

Reprod. Nutr. Dev.

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-The meeting between the maternal and paternal gametes is dependant upon a number of complicated processes. On the maternal side it involves maturation of the oocytes under the influence on both peripheral and follicular endocrine factors. Deviations in the normal pattern of maturation will lead to ovulation of inferior oocytes. On the paternal side the transport of spermatozoa in the female genital tract following mating is an area of great importance. The establishment of the sperm reservoir in the isthmus is dependant upon a number of factors (intracellular calcium concentrations, oligo-saccharides, change in estradiol: progesterone ratio in the afferent blood supply). Alterations of the normal micro-environment may disturb both binding, release and transport as a whole. The process of fertilization occurs in the ampullar region of the oviduct and it involves several well tuned steps: binding to the zona pellucida where the acrosome reaction takes place, penetration, fusion between the oolemma and the sperm plasma membrane, activation with the release of the cortical granules, decondensation of the sperm chromatin, pronucleus formation and finally syngamy where the two pronuclei fuses. The egg will experience the first cleavage shortly thereafter. Superovulation may disturb a number of these processes including oocyte maturation (arrest at MI) and sperm and zygote transport in the oviduct caused by the deviant endocrine environment, thus leading to a higher incidence of lack of fertilization and poor embryos quality. oocyte maturation / capacitation / fertilization / superovulation Reprod. Nutr. Dev. 41 (2001) [451][452][453][454][455][456][457][458][459] 451

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Inhibition of sperm transport and fertilization in superovulating ewes

Cited by 37 publications

References 18 publications

A study on the effect of GnRH administration on the ovarian response and laparoscopic intrauterine insemination of Awassi ewes treated with eCG to induce superovulation

A study on the effect of GnRH administration on the ovarian response and laparoscopic intrauterine insemination of Awassi ewes treated with eCG to induce superovulation

Fertilization and ovum recovery rates in superovulated ewes following cervical insemination or laparoscopic intrauterine insemination at different times after progestagen withdrawal and in one or both uterine horns

Rendez-vous in the oviduct: implications for superovulation and embryo transfer

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