Comparison of prostaglandin- and progesterone-based protocols for timed artificial insemination in sheep

Olivera-Muzante, J.; Fierro, S.; López, Verónica; Gil, J.

doi:10.1016/j.theriogenology.2010.11.036

Cited by 51 publications

(27 citation statements)

References 30 publications

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“…Most research conducted in sheep to compare both treatments has concluded that prostaglandin analogues lead to variable fertility rates (Barrett et al. 2002) and decreased reproductive performance (Olivera‐Muzante et al. 2011).…”

Section: Introductionmentioning

confidence: 99%

Endometrial Expression of IFNAR‐1 and Oxytocin Receptor (OTR) is not Improved by Prostaglandin Analogues when Compared to Progestagens in Ewes

Ruiz-Gonzalez¹,

Sánchez²,

García-Fernández³

et al. 2011

Reprod Domestic Animals

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The objective of this study was to investigate differences on the endometrial immunoexpression of type I IFN receptor subunit 1 (IFNAR1) and oxytocin receptor (OTR) during the time of maternal recognition of pregnancy in sheep, when oestrus is synchronized with either prostaglandin analogues (group PG) or conventional progestagens (group P). Plasma progesterone was measured from day 0 to 21 post-coitus (pc) (day 0 = day of oestrus). Immunohistochemistry was performed in samples of uterine horns from pregnant sheep on days 9pc, 13pc, 15pc, 17pc and 21pc to locate IFNAR1 and OTR expression in different endometrial compartments. Mean levels of plasma progesterone were different between treatments, obtaining higher levels in the PG group than in the P group (p < 0.05). Comparing days of pregnancy, IFNAR1 protein expression was different in the luminal epithelium (LE) (p < 0.05), while OTR was different in the LE and in the superficial glandular epithelium (SG) (p < 0.05). Temporal variation on the expression of both proteins from day 9pc to 21pc has been evidenced. IFNAR1 and OTR expression did not show significant differences between treatments. However, the response observed in the endometrium was highly inconsistent when prostaglandin analogues were used. Therefore, the protocol based on prostaglandin analogues still needs to be optimized before being considered as a better alternative to progestagens for oestrous synchronization in sheep.

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Section: Introductionmentioning

confidence: 99%

Endometrial Expression of IFNAR‐1 and Oxytocin Receptor (OTR) is not Improved by Prostaglandin Analogues when Compared to Progestagens in Ewes

Ruiz-Gonzalez¹,

Sánchez²,

García-Fernández³

et al. 2011

Reprod Domestic Animals

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“…Although there is no consensus regarding to the optimal time for cervical FTAI after progestagens/eCG, several authors inseminate at 52-57 h (Donovan et al, 2004;Manes et al, 2010;Olivera-Muzante et al, 2011;Viñoles et al, 2011). Thus, time of 54 h for single AI was selected on the basis of the literature.…”

Section: Resultsmentioning

confidence: 99%

Fixed-Time Artificial Insemination in dairy ewes raised in field conditions in Argentina

Simonetti

Maria

Mercedes

2014

AVB

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-Modern systems of sheep production are directed towards intensification, being in this line the adoption of artificial insemination. The objective was to compare two protocols of fixed-time artificial insemination (FTAI) in dairy ewes managed under field conditions in Buenos Aires province, Argentina. Twenty four two-tooth Milchschaf x Texel ewes, aging 18 months, were synchronized with intravaginal sponges plus 300 IU eCG and cervically inseminated with fresh semen either once at 54 h (Group A) or twice at 48 and 60 h (Group B) after sponge removal. Additionally, a second experiment was performed to detect the estrus onset; thus, 23 Milchschaf x Texel ewes were synchronized as previously described and estrus was detected at 6-h intervals by teaser rams. The pregnancy rate was higher in B than in A (B: 50.0% vs. A: 9.1%; P < 0.05). In the group exposed to teasers, 91.3% of the ewes came into estrus from 24 to 36 h after sponge removal, with an interval to estrus averaging 30.6  1.0 h. Based on both type of mucus mostly observed and data of estrus outcome, it could be suggested that the difference in effectiveness between protocols would be related to an earlier rather than to a double insemination. In conclusion, this study provides information on the application of FTAI in dairy ewes reared rangeland in Argentina.Keywords: Sheep, reproduction, AI, FTAI, synchronization.RESUMO -Sistemas modernos de produção de ovinos são direcionados para a intensificação, sendo nesta linha a adoção da inseminação artificial. O objetivo foi comparar dois protocolos de inseminação artificial em tempo fixo (IATF) em ovelhas leiteiras criadas em condições de campo na provincia de Buenos Aires, Argentina. Vinte e quatro ovelhas Milchschaf x Texel com "pinças permanentes", de 18 meses de idade, foram sincronizadas com esponjas intravaginais e 300 UI de eCG e inseminadas por via cervical com sêmen fresco. As IATF foram realizadas uma vez às 54 h (Grupo A) ou duas vezes às 48 e 60 h (Grupo B) após a retirada da esponja. Foi realizado um segundo experimento com 23 ovelhas Milchschaf x Texel, as quais foram sincronizadas como descrito anteriormente e seus estros foram detectados em intervalos de 6 h por rufiões. A taxa de prenhez foi maior em B do que em A (B: 50,0% vs A: 9,1%; P < 0,05). No grupo exposto a rufiões, 91,3% das ovelhas entraram em estro 24-36 h após a retirada da esponja, com um intervalo médio ao estro de 30,61,0 h. Com base no tipo de muco mais freqüentemente observado e nos resultados da apresentação de estro, pode ser sugerido que a diferença na eficácia entre protocolos estaria mais relacionada com a precocidade do estro em relação aos tempos pré-estabelecidos para as inseminações do que propriamente o número de inseminações. Em conclusão, este estudo oferece informação sobre a aplicação da IATF em ovelhas leiteiras criadas nas pastagens da Argentina.Palavras-Chave: Ovinos, reprodução, IA, IATF, sincronização.

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“…However, the effectiveness of PGF 2α or its analogues depends on the ovary status (Houghton, et al, 1995) and is not very useful during the anoestrous season (Acritopoulou & Haresign, 1980). Moreover, a varied response and low pregnancy rates in AI have been reported with single PGF 2α treatment or progestagen combined (Boland, et al, 1978;Hackett, et al, 1981;Olivera-Muzante, et al, 2011), so with the current methods it is not an appropriate synchronisation treatment for AI unless previous oestrous detection is carried out. Another factor affecting fertility after cervical AI related with hormonal synchronisation is the development of anti-eCG antibodies.…”

Section: Synchronization Treatmentmentioning

confidence: 99%

Management Factors Affecting Fertility in Sheep

Santolaria¹,

Palacín²,

Yániz³

2011

Artificial Insemination in Farm Animals

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Comparison of prostaglandin- and progesterone-based protocols for timed artificial insemination in sheep

Cited by 51 publications

References 30 publications

Endometrial Expression of IFNAR‐1 and Oxytocin Receptor (OTR) is not Improved by Prostaglandin Analogues when Compared to Progestagens in Ewes

Endometrial Expression of IFNAR‐1 and Oxytocin Receptor (OTR) is not Improved by Prostaglandin Analogues when Compared to Progestagens in Ewes

Fixed-Time Artificial Insemination in dairy ewes raised in field conditions in Argentina

Management Factors Affecting Fertility in Sheep

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