Reproductive performance in out-of-breeding season of fatty ewes using implant norgestomet with or without PMSG

Garoussi, Massoud Talebkhan; Farzaneh, Nima; Gallehdar, Ehssan; Mohri, Mehrdad

doi:10.1007/s11250-011-9993-z

Cited by 11 publications

(7 citation statements)

References 11 publications

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“…Our protocol would have overcome this drawback because progestagen was administered through a subcutaneous device implanted in the animal's ear. Furthermore, norgestomet implants placed subcutaneously in the ears of ewes are known to increase serum progesterone levels [20]. …”

Section: Discussionmentioning

confidence: 99%

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

et al. 2014

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Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 ± 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.

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Section: Discussionmentioning

confidence: 99%

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

et al. 2014

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“…(2001), 3 mg of Norgestomet was effective at inducing estrus in ewes during the breeding season, with average intervals from 36 to 74 h between the removal of the device and subsequent ovulation. In addition, pregnancy rates varied between 60 and 72% in ewes synchronized with protocols based on Norgestomet during the non-breeding season in previous studies (Awel et al, 2009;Garoussi et al, 2012;Uslu et al, 2012).…”

Section: Discussionmentioning

confidence: 92%

“…production, especially where reproduction is affected by photoperiod (Takada et al, 2012). Studies have thus been performed to describe the effects of seasonality on changes in the reproductive tract of ewes and to evaluate the hormonal induction to improve fertility (Garoussi et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…The use of Norgestomet implants inserted subcutaneously in the back of the ear has been reported to improve fertility in ewes (Castilho et al, 2007;Awel et al, 2009;Garoussi et al, 2012;Santos and Barcelos, 2012;Dogan et al, 2018). However, the use of commercial doses of Norgestomet in ewes is still in the incipient stages compared with the use of other devices, and further studies are necessary to evaluate its effects on animal reproduction.…”

Section: Introductionmentioning

confidence: 99%

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Effectiveness of a low-dose Norgestomet ear implant in short-term protocols to induce estrus in ewes during the non-breeding season in Brazil.

et al. 2019

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The objective of this study was to evaluate the reproductive performance of ewes subjected to a short-term protocol for estrus induction using 1 mg of Norgestomet during the non-breeding season in Brazil. A total of 84 ewes were randomly divided into two equal groups (n = 42 per group). Controlled Internal Drug Release (CIDR) containing 330 mg progesterone was inserted into the vagina in the first 42 ewes, and for the other 42 ewes in the second group, 1 mg of Norgestomet was placed subcutaneously in the convex surface of the ear. Implants and devices were removed in both groups on day 6. Following the removal of implants and devices, 10 mg of PGF2α and 300 IU of eCG were injected in all the ewes. After 48 h of application, three fertile rams were added to the herd. Ewes and rams were kept together for four days. Rams were removed on day 12, and after 42 days, pregnancy was diagnosed by ultrasound scanning. Short-term protocols using either an intravaginal device or ear implant were similarly effective to estrus induction (95.23 vs. 92.85%), and all ewes from both groups had estrus manifestation within 72 h after implant removal (72±9 h). In addition, no significant difference in pregnancy rate was observed between ewes treated with the intravaginal device and ear implant protocols (52.38 vs. 57.14%). These results suggest that 1 mg of Norgestomet is a good alternative for short-term protocols for estrus induction/ synchronization during the non-breeding season in ewes. It is possible to replace the progesterone-releasing intravaginal device by the ear implant and obtain the same reproductive effectiveness in ewes.

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“…However, this ovulation is not accompanied by estrous behavior unless ewes are primed with progestagens (Hunter and Einer-Jensen.,2005). During the non-breeding season, progestagen priming may be used for a period of time (9-14 days), followed by the administration of equine chorionic gonadotrophin (eCG) (Garoussi et al, 2019. Garoussi et al, 2012.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Ram Exposure, Progestogen and eCG on Reproductive Performance of Fat Tail Ewes in Non-Breeding Season

Garoussi

Mavadati

Bahonar

et al. 2021

Preprint

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Sheep are considered short-day breeders. Exposure of rams to anestrus ewes results in an increase in LH secretion. The aims of this study was to determine whether the presence and exposure of rams can effect on reproductive performance such as: pregnancy rate, litter size, sex of lamb, fecundity rate and prolificacy rate of fat tail Iranian Shaal breed ewes in non-breeding season using progesterone (p4) analogue with or without equine chorionic gonadotropin (eCG). Totally, 100 ewes out of 138 non-cyclic ewes with <0.5ng/ml P4 were selected for this study. They were aged 2 to >7 years old. They were stratified to two groups (control and treatment). The ewes in treatment and control groups received 13 days a sponge containing 60 mg medroxyprogesterone acetate (MPA). The treatment group consists of 3 subgroups and each group contains 25 ewes equally. They were included: 1- P4, eCG and Ram exposure. 2- P4 and ram exposure. 3- P4 and eCG. Ewes in control group received only P4. The ewes were located in isolated corrals for 40 days. The ram to ewe ratio was 1 to 5. Twenty healthy rams were housed in an isolated pen from ewes with distance 1500 m during 40 days. Rams exposed three days before sponge withdraw (day 10). They were separated by considerable distance (2 meters) using fence. The related groups received 500 IU eCG on the day of sponge removal (day 13). The rams were released into the ewe flock after removing the sponge in treatment and control groups. Pregnancy diagnosis performed using transabdominal ultrasonography. The obtained data analyzed using SPSS version 16. The conception rate in treatment and control groups were differed significantly (P<0.01). The conception rate in P4+ram exposure+ eCG, P4+ramexposure and P4+ eCG were 96%(no.24), 80%(no.20) and 88%(no.22), respectively. However, the conception rate in control group was 60% (no. 15). The fecundity rates were 136%, 100% and 124% in treatment subgroups, however, it was 84% in control group, respectively. There were no significant differences among genus and weight of lambs in treatments subgroups and control group (P>0.05). It is concluded that ram exposure can increase significantly reproductive performance in non-breeding season fat tailed ewes Shaal breed.

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Reproductive performance in out-of-breeding season of fatty ewes using implant norgestomet with or without PMSG

Cited by 11 publications

References 11 publications

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

Effectiveness of a low-dose Norgestomet ear implant in short-term protocols to induce estrus in ewes during the non-breeding season in Brazil.

The Effects of Ram Exposure, Progestogen and eCG on Reproductive Performance of Fat Tail Ewes in Non-Breeding Season

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