Returning of cyclicity in infertile Corriedale sheep with natural progesterone and GnRH based strategies

Lone, Farooz Ahmad; Malik, Asloob Ahmad; Khatun, Arjuma; Shabir, Mir; Islam, Rumana

doi:10.1016/j.apjr.2015.12.012

Cited by 2 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, no animal showed estrus or was served in any of the groups. Thus, in contrast to what has been reported in Altamurana sheep [10] and in Corriedale ewes [11], treatments based on GnRH alone or combined with PGF2α were unable to induce fertile estrus in seasonally anestrous Suffolk ewes. Despite this, and since the results of P4 determinations provided evidence that the treatments had an initial effect on ovarian activity, we decided to evaluate the combination of these treatments with the male effect at the next anestrous season (experiment 2).…”

Section: Discussioncontrasting

confidence: 84%

“…The results of the present study call into question the effectiveness of PGF2α administration a few days after induction of ovulation with GnRH. It has been reported that PGF2α can be luteolytic in the ewe as soon as day 3 post-ovulation [4], and that it has been effective when administered 5 days after the induction of ovulation with GnRH [9–11]. However, in the present study the inclusion of PGF2α 6 days after administration of the first dose of GnRH in the GPG group was ineffective to induce luteolysis in a significant proportion of animals, since 35% of the ewes in this group had a normal-length first luteal phase that was not interrupted by PGF2α administration.…”

Section: Discussionmentioning

confidence: 99%

“…However, very little information is available regarding the use of such protocols during the anestrous season. Published studies on the use of GnRH-PGF2α protocols in anestrous ewes relied on estrus detection to assess their efficacy, and P4 determinations were not made to characterize the actual ovarian effects of the treatments [10,11]. Some of the GnRH-PGF2α combinations showed potential for steroid-free induction of ovarian activity, but the lack of P4 measurements prevents complete interpretation of the findings.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Induction of fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes

Miguel-Cruz

Mejía-Villanueva

Zarco

2019

Asian-Australas J Anim Sci

View full text Add to dashboard Cite

ObjectiveTo evaluate the efficacy of treatments based on gonadotrophin-releasing hormone (GnRH), GnRH-prostaglandin F2α (PGF2α), and/or intense exposure to novel rams to induce fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes.MethodsIn the first experiment, ewes were treated with one injection of GnRH, two injections of GnRH administered 7 days apart, or a sequence of GnRH-PGF2α-GnRH (GPG). In the second experiment anestrous ewes were exposed, for 36 days starting on the day of weaning, to groups of four rams of three different breeds that were alternated every day. Besides exposure to the male effect (ME), the ewes were injected with saline solution (ME group, n = 20), with GnRH (ME-GnRH group, n = 20) or with a sequence of GnRH-PGF2α-GnRH (ME-GPG group, n = 20). The rams used for male-effect were fitted with aprons to prevent mating, and ewes detected in estrus were bred to selected fertile rams. Ovarian activity was monitored by progesterone determinations in both experiments.ResultsIn the first experiment sustained induction of ovarian activity was not achieved and no ewe was detected in estrus. In the second experiment induction of sustained ovarian activity was achieved in all groups. Most of the ewes were detected in estrus, 76.7% of the ewes were mated during a 36-d breeding period and 71.7% of all the ewes became pregnant during that period. No significant differences between groups were found for any of these variables. However, estrus detection efficiency was higher in the ME-GnRH group than in the ME group (p<0.05).ConclusionAn intense male-effect, that included the continuous presence and frequent alternation of several rams of different breeds, was sufficient to induce ovarian activity and fertile estrus in Suffolk ewes during the period of deep anestrus without the use of hormones, although addition of GnRH improved the efficiency of estrus detection.

show abstract

Section: Discussioncontrasting

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Induction of fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes

Miguel-Cruz

Mejía-Villanueva

Zarco

2019

Asian-Australas J Anim Sci

View full text Add to dashboard Cite

show abstract

“…In the present study, estrus was spontaneously exhibited in 60% of ewes in control group, while Ovsynch protocol "GPG" produced about 50% estrus response rate. Other workers reported lower values; Martemucci and D'Alessandro obtained 33.3% response rate in Awassi ewes (Martemucci and D'Alessandro, 2010a), Lone et al obtained a value of 28.75% in infertile ewes (Lone et al, 2016). Interestingly, GPG program failed to induce estrus in Rahmani ewes out of breeding season (Almadaly et al, 2016).…”

Section: Discussionmentioning

confidence: 90%

“…Usually duration of progesterone treatment is between 5 and 14 days with variable fertility rates (Alnimer et al, 2005;Martemucci and D'Alessandro, 2010b); progesteronebased protocols can also be used to induce estrus during non-breeding season in sheep (Almadaly et al, 2016). gonadotropin-releasing hormone (GnRH) injection 24 hours after sponge removal as alternative to eCG was tested and proven to induce estrus in infertile ewes (Lone et al, 2016). Administration of progesterone or its analogues for estrus synchronization is based on simulating the action of natural progesterone produced during luteal phase of estrous cycle, which controls LH secretion from the pituitary gland (Abecia et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Synchronization of Estrus in Field Conditions Using Progestagen Sponge, GnRH, and PGF2 and #945; in Barki Ewes during Breeding Season

Waheeb¹,

El-Amrawi²,

Metwelly³

et al. 2017

AJVS

View full text Add to dashboard Cite

Key words:estrus synchronization, progestagen sponge, PGF2α, ewes, breeding season This study was conducted to evaluate reproductive performance of Barki ewes subjected to three estrus synchronization programs in field conditions during breeding season. For this purpose, 36 cycling ewes were divided into 4 groups according to the program assigned: Group SeCG (n=10): received intravaginal progesterone sponge (40 mg Fluorogestone acetate, Chrono-gest®, Intervet International) for 7 days, at time of sponge removal, each ewe received i.m injection of 500 IU eCG (Folligon®, Intervet International); Group PG-PG (n=10): received double injections of 250μg Cloprostenol (PGF2α analogue, Estrumate®, Intervet International) 11 days apart; Group GPG (n=6): received 4μg Buserelin by i.m injection on day 0 (GnRH analogue-Receptal®, Intervet International), on day 5 animals received 250μg Cloprostenol followed by 4μg Buserelin by i.m injection on day 7; Group C (n=10): served as control group that did not receive any treatment. Results showed that estrus induction rate was significantly high in SeCG group that was recorded at 100% (P<0.05), while it was 90%, 60%, and 50% for PG-PG, C and GPG respectively. Estrus synchrony was more uniform in SeCG group as 70% of ewes exhibited estrus around 24-36 hrs from end of treatment. There was no significant difference among groups in pregnancy and lambing rate (p>0.05). Pregnancy rates were 100%, 90%, 88.9%, and 83.3% for GPG, SeCG, PG-PG, and C group respectively. Conclusion, from results we conclude that intravaginal progesterone sponge for 7 days+500IU eCG at sponge removal is convenient for estrus synchronization of ewes raised in field conditions during breeding season. Moreover, reproductive and fertility parameters recorded in the current study are acceptable and within values reported previously in farm conditions.

show abstract

Returning of cyclicity in infertile Corriedale sheep with natural progesterone and GnRH based strategies

Cited by 2 publications

References 17 publications

Induction of fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes

Induction of fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes

Synchronization of Estrus in Field Conditions Using Progestagen Sponge, GnRH, and PGF2 and #945; in Barki Ewes during Breeding Season

Contact Info

Product

Resources

About