Effect of estrus synchronization and artificial insemination on reproductive performance of Merino sheep

Simonetti, Laura; Ramos, Guillermo; Gardón, Juan Carlos

doi:10.1590/s1413-95962002000300006

Cited by 8 publications

(5 citation statements)

References 8 publications

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“…Although ewes in G3 showed lowest values of lambing rates (62.5%), they produced the highest number of lambs, reflecting significantly (P<0.05) the highest fecundity and twining rates (112.5% and 1.80 lamb /ewe) due to the greatest number of twins as compared to other treatment and control groups (Table 4). The obtained conception rate in this study is comparable with the results obtained by Simonetti et al (2002) in Merino ewes in 400 IU PMSG (60%). Also, lambing rates presented in this study are in agreement with earlier reports which showed that the types of estrous synchronization have relatively less suppressive effects on LH secretion than the CL secreted P4 and are associated with high LH pulse frequency and development of "persistent follicles" containing aged oocytes.…”

Section: Reproductive Performance Of Ewessupporting

confidence: 88%

“…In accordance with the present results of twining rate, Ince and Karaca (2009) reported that the litter size of in Chio×Kivircik ewes was1.33 and 1.39 for 400 and 500 IU PMSG, respectively. However, higher values were reported by Simonetti et al (2002), who reported an average litter size of 1.45 in Merino ewes treated with 400 IU PMSG. These variations are depending on various factors such as breed, age, time and dose of PMSG administration (Dogan and Nur, 2006).…”

Section: Reproductive Performance Of Ewesmentioning

confidence: 66%

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Estrus Synchronization in Ewes Using Sponges With PMSG or Ram Effect With or Without Progesterone Injection

Abdel-Khalek

Khalil

El-Saidy³

et al. 2014

Journal of Animal and Poultry Production

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Total of 40 crossbred ewes were divided into five treatment groups (8 ewes each). Ewes in the first group (G1) represented the control ewes which were allowed for natural mating. The control ewes were exposed to fertile ram from the contemporary to that of treatment groups start time up to the end of the breeding season (end of September) and natural mating was applied for those coming in estrus. Ewe in the other four treatment groups G2, G3, G4 and G5 treatment groups were inserted with 20 mg sponges for 11 days, and ewes in G2 were injected with 300 IU PMSG on the Day 11 (sponge withdrawal), ewes in G3 the same treatment of G2 but injected with 1 ml progesterone (Lutone) before the sponge withdrawal with 24 h (Day 10), ewes in G4 after sponge withdrawal teaser introduce ram kept until artificial insemination was done. Ewes in G5 the same treatment of G4 but injected with 1 ml progesterone (Lutone) before the sponge withdrawal with 24 h (Day 10). Ewes in all treatment groups were artificially inseminated twice 48 and 56 hr after the sponge removed with fresh diluted semen. Blood samples were taken during treatment period for P4 assay.Results show that estrus rate was 100% in treatment groups and onset of estrus was the latest (P<0.05) with the longest duration (P<0.05) in ewes of G5, while those in G2 showed an opposite trend. Lambing rate was the highest (P<0.05) in G2 and G5 (75%), moderate in G3 and G4 (62.5%) and the lowest in G1 (50%). Ewes in G3 showed the highest (P<0.05) fecundity and twining rates (112.5% and 1.80 lamb /ewe) due to the greatest number of twins as compared to other treatment and control groups. The differences in average LBW of lambs at birth between all treatment groups and the control one were not significant. There was marked differences in P4 level according to treatment and lambing in different groups. In conclusion, the findings of the present research indicate that primary P4 and PMSG is a beneficial adjunct to the breeding of sheep by AI at progestagens-synchronized estrus and administration of 300 IU PMSG at sponge withdrawal is more effective for increasing the reproductive performance of artificially inseminated crossbred ewes in breeding season.

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Section: Reproductive Performance Of Ewessupporting

confidence: 88%

Section: Reproductive Performance Of Ewesmentioning

confidence: 66%

Estrus Synchronization in Ewes Using Sponges With PMSG or Ram Effect With or Without Progesterone Injection

Abdel-Khalek

Khalil

El-Saidy³

et al. 2014

Journal of Animal and Poultry Production

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“…In the present study, faster genetic progress and profit from village-based scheme was predicted through improved breeding management and estrous synchronization. Similarly, a previous study on mature Merino ewes [23] reported 54.32% lambing rate over natural synchronized lambing after cervical artificial insemination following a progestagen (MAP)-PMSG (375IU) treatment. In these scenarios, higher selection intensity is exploited to result in higher predicted annual genetic gain and profit.…”

Section: Discussionmentioning

confidence: 66%

Conservation-based breeding program design for genetic improvement in Gumz sheep in the western lowlands of Ethiopia

et al. 2018

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Background: Genetic improvement in livestock in developing countries like Ethiopia remains challenging; selectionbased breeding schemes have the potential to provide resource-poor producers with access to improved animals that could ensure increased productivity of animals and hence contribute to reduced poverty. Therefore, the aim of this study was to compare alternative breeding program designs to improve productivity of Gumz sheep for sustainable utilization and conservation of genetic resource. In this paper, two village-based and two central nucleus-based sheep breeding schemes were modeled and evaluated in terms of their biological and economic efficiencies. The schemes were scheme-1: a village-based breeding scheme with existing lambing, scheme-2: a village-based scheme with improved lambing, scheme-3: central nucleus-based scheme with 5% nucleus size and scheme-4: central nucleus-based scheme with 10% nucleus size. Results:The annual genetic gains per year in 6-month weight (kg) were differed across schemes and ranged from 0.154 to 0.171 in village-based scheme, and 0.334 to 0.336 in central-based schemes. The annual genetic gain per year in number of lambs born per ewe bred ranged from 0.0017 to 0.0036% in both village-and central nucleus-based scheme. The genetic gain in the proportion of lambs weaned per ewe was comparable across central nucleus-based scheme but little differed in village-based schemes and ranged from 0.0015 to 0.0016%. Conclusion:Central nucleus-based schemes resulted in the highest genetic gain and economic efficiencies in all breeding objectives compared to village-based schemes. However, this scheme requires establishing a very large central nucleus flocks. Village-based scheme with estrous synchronization was the best option. The expected genetic gains and profits were higher as it promotes participation of farmers and achieving concentrated lambing which in turn increase selection intensity and genetic progress. This suggested the possibility for sustainable Gumz sheep improvement and conservation through village-based schemes and estrous synchronization.

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“…More precisely, a fertility rate of 65% in Argentine and South Africa has been reported in Merino sheep using fresh diluted semen (Bonato et al, 2021; Fernandez et al, 2019). In another study, Ben Moula et al (2023) have recently reported a lower fertility rate of 61% in Sardi sheep using semen stored in SM at 5°C for 5 h. However, Simonetti et al (2002) reported a greater value (up to 76.47% fertility) while using fresh diluted semen. It is essential to consider that factors such as season, synchronization protocol, semen collection method, insemination technique and number of spermatozoa per dose can influence fertility rates across studies.…”

Section: Discussionmentioning

confidence: 96%

Comparative evaluation of Duragen® and skim milk extenders to enhance ram semen quality and fertility: A promising alternative in ovine artificial insemination

El Amiri,

Ben Moula,

El Khelfaoui

et al. 2023

Reprod Domestic Animals

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This study aimed to investigate the effectiveness of Duragen® and skimmed milk (SM) extenders on the quality parameters, bacterial load and fertilization ability of stored ram semen. A total of 50 ejaculates from Sardi rams (n = 5) aged 2.5–3 years, were collected and stored in Duragen® and SM at 15°C. The motilities and velocity parameters generated by the CASA system were then evaluated at 0, 8 and 24 h of storage. Afterward, bacterial loads of sperm extended in Duragen® and SM were determined at 0, 5 and 24 h of incubation. In addition, ewes (n = 100) aged 2 years, have been chosen in the same herd. The selected ewes were then synchronized and inseminated using semen extended in Duragen® and SM and stored for 5 h at 15°C. The results revealed that total and progressive motilities, straight velocity (VSL), straightness (SRT), lateral head displacement (ALH) and beat cross frequency (BCF) were not affected by the extender type after 24 h of storage (p > .05). However, curvilinear velocity (VCL), velocity average path (VAP), linearity (LIN) and wobble (WOB) showed higher values in Duragen® compared with SM extender after 24 h of storage (p < .05). Bacterial loads were observed mainly in sperm stored in SM at 5 h (183 UFC/mL) and at 24 h (357 UFC/mL) of incubation. However, the only case showing a bacterial load in Duragen® is when the storage time attains 24 h (199 UFC/mL). Concerning fertility, sperm diluted in both extenders resulting in high fertility rates which reaches 66% and 73% for Duragen® and SM, respectively, with no statistical difference (p > .05). In summary, Duragen® extender decreased bacterial load in stored semen and maintained high ram sperm quality and fertility. These findings suggest that Duragen® extender could be used as SM alternative in ovine artificial insemination (OAI).

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Effect of estrus synchronization and artificial insemination on reproductive performance of Merino sheep

Cited by 8 publications

References 8 publications

Estrus Synchronization in Ewes Using Sponges With PMSG or Ram Effect With or Without Progesterone Injection

Estrus Synchronization in Ewes Using Sponges With PMSG or Ram Effect With or Without Progesterone Injection

Conservation-based breeding program design for genetic improvement in Gumz sheep in the western lowlands of Ethiopia

Comparative evaluation of Duragen® and skim milk extenders to enhance ram semen quality and fertility: A promising alternative in ovine artificial insemination

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