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Approaches of estrous synchronization in sheep: developments during the last two decades: a review

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Abstract

The objective of the current review was to summarize the protocols used for estrous synchronization in ewes during the last two decades. Progesterone (P4) is a major hormone used in most protocols. P4 in the form of a controlled internal drug releasing (CIDR) device, medroxyprogesterone acetate (MAP), and fluorogestone acetates (FGA) has been used for estrous synchronization. Also, gonadotropins such as equine chorionic gonadotropin (eCG) and gonadotropin-releasing hormone (GnRH) are often administered at the end of P4-based protocols to improve fertility. Moreover, the administration of prostaglandins (PG) and ram effects have been used for estrus induction and synchronization of ewes. The findings of previous studies indicate that the outcome of administering various synthetics P4 analogues (CIDR, MAP, and FGA) in ewes is comparable in terms of estrous synchronization/induction. The supplementation of P4-based protocols with eCG, however, improves the estrus response and pregnancy rate during breeding and non-breeding season. On the other hand, PG is effective for successful estrous synchronization during the breeding season only. Often, two injections of PG are administered either 11 or 14 days apart along with P4-based protocols to lyse ovine corpus luteum (CL) when it is receptive to PG i.e., 3 days post-ovulation. Alternatively, the “ram effect” has been shown to improve the efficacy of P4-based protocols and can be used as an alternative to eCG in ewes. The current review describes the methods of synchronization and their outcomes during breeding and a non-breeding season in ewes.

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References

  • Abdullah, A., Husein, M., and Kridli, R., 2002. Protocols for estrus synchronization in Awassi ewes under arid environmental conditions. Asian Australasian Journal of Animal Sciences, 15, 957-962.

    Article  Google Scholar 

  • Akoz, M., Bulbul, B., Bozkurt A, M., and Dere, S., 2006. Induction of multiple births in Akkaraman cross-bred sheep synchronized with short duration and different doses of progesterone treatment combined with PMSG outside the breeding season. Bulletin-Veterinary Institute in Pulawy, 50, 97.

    Google Scholar 

  • Akusu, M., and Egbunike, G., 1984. Fertility of the West African Dwarf goat in its nagative environment following prostaglandin F2‐alpha induced estrus. Veterinary Quarterly, 6, 173-176.

    Article  CAS  PubMed  Google Scholar 

  • Al-Hamedawi, T., Khammas, D., and Al-Ubaidi, A., 2003. Effect of estrus synchronization on vaginal flora and subsequent fertility in ewes. Iraqi Journal of Veterinary Sciences, 16, 73-79.

    Google Scholar 

  • Allison, A., and Kelly, R., 1978. Synchronisation of oestrus and fertility in sheep treated with progestagen-impregnated implants, and prostaglandins with or without intravaginal sponges and subcutaneous pregnant mare's serum. New Zealand Journal of Agricultural Research, 21, 389-393.

    Article  Google Scholar 

  • Altincekic, S.O., and Koyuncu, M., 2019. The effects of short-mid-long term intravaginal sponge application on reproductive performance of Karacabey Merino ewes in the anestrous season. Indian Journal of Animal Research, 53, 33-36.

    Google Scholar 

  • Atalla, H., 2018. The effects of different doses of equine chorionic gonadotropin on induction of estrus and reproductive patterns in Assaf ewes out of breeding season. International Journal of Current Microbiology and Applied Sciences, 7, 2078-2085.

    Article  CAS  Google Scholar 

  • Awel, H., Eshetu, L., Tadesse, G., Birhanu, A., and Khar, S., 2009. Estrus synchronization in sheep with synthetic progestagens. Tropical animal health and production, 41, 1521-1524.

    Article  PubMed  Google Scholar 

  • Barrett, D., Bartlewski, P., Batista-Arteaga, M., Symington, A., and Rawlings, N., 2004. Ultrasound and endocrine evaluation of the ovarian response to a single dose of 500 IU of eCG following a 12-day treatment with progestogen-releasing intravaginal sponges in the breeding and nonbreeding seasons in ewes. Theriogenology, 61, 311-327.

    Article  CAS  PubMed  Google Scholar 

  • Bartlewski, P., Beard, A., Cook, S., Chandolia, R., Honaramooz, A., and Rawlings, N., 1999. Ovarian antral follicular dynamics and their relationships with endocrine variables throughout the oestrous cycle in breeds of sheep differing in prolificacy. Reproduction, 115, 111-124.

    Article  CAS  Google Scholar 

  • Biehl, M.V., de Ferraz Junior, M.V.C., Barroso, J.P.R., Susin, I., Ferreira, E.M., Polizel, D.M., and Pires, A.V., 2019. The reused progesterone device has the same effect on short or long estrus synchronization protocols in tropical sheep. Tropical Animal Health and Production, 51, 1545-1549.

    Article  PubMed  Google Scholar 

  • Bragança, J.F., Maciel, J.M., Girardini, L.K., Machado, S.A., da Rocha, J.F., Tonin, A.A., and da Rocha, R.X., 2017. Influence of a device intravaginal to synchronization/induction of estrus and its reuse in sheep vaginal flora. Comparative Clinical Pathology, 26, 1369-1373.

    Article  CAS  Google Scholar 

  • Bragança, J.F.M., Drissen, R.O., Machado, S.A., Bennemann, P.E., and da Rocha, R.X., 2019. Efficacy of the re-utilization of an ear implant impregnated with progestogen in estrus synchronization response and pregnancy in sheep. Tropical Animal Health and Production, 51, 1763-1765.

    Article  PubMed  Google Scholar 

  • Chao, L.M., Takayama, K., Nakanishi, Y., Hamana, K., Takagi, M., Kubota, C., and Kojima, T., 2008. Luteal lifespan and fertility after estrus synchronization in goats. Journal of Veterinary Science, 9, 95-101.

    Article  PubMed  PubMed Central  Google Scholar 

  • Contreras-Solis, I., Vasquez, B., Diaz, T., Letelier, C., Lopez-Sebastian, A., and Gonzalez-Bulnes, A., 2009. Efficiency of estrous synchronization in tropical sheep by combining short-interval cloprostenol-based protocols and “male effect”. Theriogenology, 71, 1018-1025.

    Article  CAS  PubMed  Google Scholar 

  • Contreras-Solis, I., Vasquez, B., Diaz, T., Letelier, C., Lopez-Sebastian, A., and Gonzalez-Bulnes, A., 2009b. Ovarian and endocrine responses in tropical sheep treated with reduced doses of cloprostenol. Animal reproduction science, 114, 384-392.

    Article  CAS  PubMed  Google Scholar 

  • Delgadillo, J.A., Gelez, H., Ungerfeld, R., Hawken, P.A., and Martin, G.B., 2009. The ‘male effect’ in sheep and goats—revisiting the dogmas. Behavioural Brain Research, 200, 304-314.

    Article  CAS  PubMed  Google Scholar 

  • Dias, J., Miranda, V., Oliveira, F., Junior, S.V., Haas, C., Costa, V., Lucia Jr, T., Vieira, A., Corcini, C., and Gasperin, B., 2020. Treatment with eCG and hCG to induce onset of estrous cycles in ewes during the non-breeding season: Effects on follicular development and fertility. Animal Reproduction Science, 212, 106232.

    Article  CAS  PubMed  Google Scholar 

  • Driancourt, M.A., and Fry, R., 1992. Effect of superovulation with pFSH or PMSG on growth and maturation of the ovulatory follicles in sheep. Animal reproduction science, 27, 279-292.

    Article  CAS  Google Scholar 

  • Emsen, E., Gimenez-Diaz, C., Kutluca, M., and Koycegiz, F., 2011. Reproductive response of ewes synchronized with different lengths of MGA treatments in intrauterine insemination program. Animal reproduction science, 126, 57-60.

    Article  CAS  PubMed  Google Scholar 

  • Evans, A., Duffy, P., Crosby, T., Hawken, P., Boland, M., and Beard, A., 2004. Effect of ram exposure at the end of progestagen treatment on estrus synchronisation and fertility during the breeding season in ewes. Animal Reproduction Science, 84, 349-358.

    Article  CAS  PubMed  Google Scholar 

  • Fierro, S., Gil, J., Viñoles, C., and Olivera-Muzante, J., 2013. The use of prostaglandins in controlling estrous cycle of the ewe: A review. Theriogenology, 79, 399-408.

    Article  CAS  PubMed  Google Scholar 

  • Fierro, S., and Olivera-Muzante, J., 2017. Long interval prostaglandin as an alternative to progesterone-eCG based protocols for timed AI in sheep. Animal Reproduction Science, 180, 78-84.

    Article  CAS  PubMed  Google Scholar 

  • Fierro, S., Olivera-Muzante, J., Gil, J., and Viñoles, C., 2011. Effects of prostaglandin administration on ovarian follicular dynamics, conception, prolificacy, and fecundity in sheep. Theriogenology, 76, 630-639.

    Article  CAS  PubMed  Google Scholar 

  • Fleisch, A., Bollwein, H., Piechotta, M., and Janett, F., 2015. Reproductive performance of Lacaune dairy sheep exposed to artificial long days followed by natural photoperiod without and with additional progestagen treatment during the nonbreeding season. Theriogenology, 83, 320-325.

    Article  CAS  PubMed  Google Scholar 

  • Forcada, F., Amer-Meziane, M.A., Abecia, J., Maurel, M.-C., Cebrián-Pérez, J., Muiño-Blanco, T., Asenjo, B., Vázquez, M., and Casao, A., 2011. Repeated superovulation using a simplified FSH/eCG treatment for in vivo embryo production in sheep. Theriogenology, 75, 769-776.

    Article  CAS  PubMed  Google Scholar 

  • Garoussi, M.T., Farzaneh, N., Gallehdar, E., and Mohri, M., 2012. Reproductive performance in out-of-breeding season of fatty ewes using implant norgestomet with or without PMSG. Tropical Animal Health and Production, 44, 965-968.

    Article  Google Scholar 

  • Gatti, M., Zunino, P., and Ungerfeld, R., 2011. Changes in the aerobic vaginal bacterial mucous load after treatment with intravaginal sponges in anoestrous ewes: effect of medroxiprogesterone acetate and antibiotic treatment use. Reproduction in Domestic Animals, 46, 205-208.

    Article  CAS  PubMed  Google Scholar 

  • Gibbons, A., Bruno-Galarraga, M., Fernandez, J., Gonzalez-Bulnes, A., and Cueto, M., 2019. Vitrified embryo transfer in Merino sheep under extensive conditions. Animal Reproduction, 16, 297-301.

    Article  PubMed  PubMed Central  Google Scholar 

  • Gonzalez-Bulnes, A., Menchaca, A., Martin, G.B., and Martinez-Ros, P., 2020. Seventy years of progestagen treatments for management of the sheep oestrous cycle: where we are and where we should go. Reproduction, Fertility and Development, 32, 441-452.

    Article  Google Scholar 

  • Gonzalez-Bulnes, A., Veiga-Lopez, A., Garcia, P., Garcia-Garcia, R., Ariznavarreta, C., Sanchez, M., Tresguerres, J., Cocero, M., and Flores, J., 2005. Effects of progestagens and prostaglandin analogues on ovarian function and embryo viability in sheep. Theriogenology, 63, 2523-2534.

    Article  CAS  PubMed  Google Scholar 

  • González-Reyna, A., Márquez-Garcı́a, E., Lizárraga-Tracy, H., and Martı́nez-González, J., 1999. Dose response effects of PMSG on ovulation rate and follicular development in Pelibuey ewes treated with Syncro-mate-B implants. Small Ruminant Research, 31, 149-155.

    Article  Google Scholar 

  • Hashemi, M., Safdarian, M., and Kafi, M., 2006. Estrous response to synchronization of estrus using different progesterone treatments outside the natural breeding season in ewes. Small Ruminant Research, 65, 279-283.

    Article  Google Scholar 

  • Hawken, P., Beard, A., Esmaili, T., Kadokawa, H., Evans, A., Blache, D., and Martin, G., 2007. The introduction of rams induces an increase in pulsatile LH secretion in cyclic ewes during the breeding season. Theriogenology, 68, 56-66.

    Article  CAS  PubMed  Google Scholar 

  • Iida, K., Kobayashi, N., Kohno, H., Miyamoto, A.,and Fukui, Y., 2004. A comparative study of induction of estrus and ovulation by three different intravaginal devices in ewes during the non-breeding season. Journal of Reproduction and Development, 50, 63-69.

    Article  PubMed  Google Scholar 

  • Karaca, F., Ataman, M., and Coyan, K., 2009. Synchronization of estrus with short-and long-term progestagen treatments and the use of GnRH prior to short-term progestagen treatment in ewes. Small Ruminant Research, 81, 185-188.

    Article  Google Scholar 

  • Kesler, D., and Favero, R., 1997. The utility of controlled-release norgestomet implants in synchronizing estrus and diagnosing pregnancy in ewes, and factors affecting the diffusion rate of norgestomet from silicone implants. Drug Development and Industrial Pharmacy, 23, 217-220.

    Article  CAS  Google Scholar 

  • Koyuncu, M., and Altıcekic, S.O., 2010. Effects of progestagen and PMSG on estrous synchronization and fertility in Kivircik ewes during natural breeding season. Asian-Australasian Journal of Animal Sciences, 23, 308-311.

    Article  CAS  Google Scholar 

  • Lewis, G.S., 2003. Steroidal regulation of uterine resistance to bacterial infection in livestock. Reproductive Biology and Endocrinology, 1, 1-8.

    Article  Google Scholar 

  • Luther, J., Grazul-Bilska, A., Kirsch, J., Weigl, R., Kraft, K., Navanukraw, C., Pant, D., Reynolds, L., and Redmer, D., 2007. The effect of GnRH, eCG and progestin type on estrous synchronization following laparoscopic AI in ewes. Small Ruminant Research, 72, 227-231.

    Article  Google Scholar 

  • Macías-Cruz, U., Ponce-Covarrubias, J., Álvarez-Valenzuela, F., Correa-Calderón, A., Meza-Herrera, C., and AvendaÑo-Reyes, L., 2013. Reproductive efficiency of Pelibuey and Romanov× Pelibuey ewes synchronized with synthetic progesterone and low doses of PMSG under a hot environment. Czech Journal of Animal Science, 58, 546-553.

    Article  Google Scholar 

  • Martin, G., Milton, J., Davidson, R., Hunzicker, G.B., Lindsay, D., and Blache, D., 2004. Natural methods for increasing reproductive efficiency in small ruminants. Animal Reproduction Science, 82, 231-245.

    Article  PubMed  Google Scholar 

  • Martinez-Ros, P., Lozano, M., Hernandez, F., Tirado, A., Rios-Abellan, A., López-Mendoza, M.C., and Gonzalez-Bulnes, A., 2018. Intravaginal device-type and treatment-length for ovine estrus synchronization modify vaginal mucus and microbiota and affect fertility. Animals, 8, 226.

    Article  PubMed Central  Google Scholar 

  • Martinez-Ros, P., Rios-Abellan, A., and Gonzalez-Bulnes, A., 2019. Influence of progesterone-treatment length and eCG administration on appearance of estrous behavior, ovulatory success and fertility in sheep. Animals, 9, 9.

    Article  Google Scholar 

  • Mura, M., Luridiana, S., Pulinas, L., Bizzarri, D., Cosso, G., and Carcangiu, V., 2019. Melatonin treatment and male replacement every week on the reproductive performance in Sarda sheep breed. Theriogenology, 135, 80-84.

    Article  CAS  PubMed  Google Scholar 

  • Naderipour, H., Yadi, J., Shad, A., and Sirjani, M.A., 2012. The effects of three methods of synchronization on estrus induction and hormonal profile in Kalkuhi ewes: a comparison study. African Journal of Biotechnology, 11, 530-533.

    CAS  Google Scholar 

  • Nakafeero, A., Hassen, A., and Lehloenya, K., 2020. Investigation of ram effect and eCG usage in progesterone based oestrous synchronization protocols on fertility of ewes following fixed time artificial insemination. Small Ruminant Research, 183, 106034.

    Article  Google Scholar 

  • Oliveira, M.E.F., Ayres, H., Oliveira, L.G.d., Barros, F.F.P.d.C., Oba, E., Bicudo, S.D., Bartlewski, P.M., Fonseca, J.F.d., and Vicente, W.R.R., 2016. Effects of season and ovarian status on the outcome of long-term progesterone-based estrus synchronization protocols and ovulatory follicle development in Santa Ines ewes under subtropical conditions. Theriogenology, 85, 452-460.

    Article  CAS  PubMed  Google Scholar 

  • Olivera-Muzante, J., Fierro, S., López, V., and Gil, J., 2011. Comparison of prostaglandin-and progesterone-based protocols for timed artificial insemination in sheep. Theriogenology, 75, 1232-1238.

    Article  CAS  PubMed  Google Scholar 

  • Quintero-Elisea, J.A., Macías-Cruz, U., Álvarez-Valenzuela, F.D., Correa-Calderón, A., González-Reyna, A., Lucero-Magaña, F.A., Soto-Navarro, S.A., and Avendaño-Reyes, L., 2011. The effects of time and dose of pregnant mare serum gonadotropin (PMSG) on reproductive efficiency in hair sheep ewes. Tropical Animal Health and Production, 43, 1567-1573.

    Article  PubMed  Google Scholar 

  • Ramírez, A.A., Villalvazo, V.M.M., Arredondo, E.S., Ramírez, H.A.R., and Sevilla, H.M., 2018. D-Cloprostenol enhances estrus synchronization in tropical hair sheep. Tropical Animal Health and Production, 50, 991-996.

    Article  PubMed  Google Scholar 

  • Risvanli, A., Demiral, O., Abay, M., Saat, N., Bekyurek, T., Kulahci, F., Niksaroglu, S., and Balci, T.A., 2010. Effect of different forms of prostaglandin F2a analogues administration on hormonal profile, prostaglandin F2a binding rate and reproductive traits in Akkaraman sheep during the breeding season. Acta Scientiae Veterinariae, 38, 391-398.

    Google Scholar 

  • Robinson, T., Salamon, S., Moore, N., and Smith, J., 1967. The evaluation of SC-9880-impregnated intravaginal sponges for the synchronization of oestrus for large scale artificial insemination of Merino ewes in summer and autumn. The evaluation of SC-9880-impregnated intravaginal sponges for the synchronization of oestrus for large scale artificial insemination of Merino ewes in summer and autumn. In: TJ Robinson (ed.), Control of the Ovarian Cycle in the Sheep. Sydney University Press, Sydney, Australia, pp. 208– 236.

    Google Scholar 

  • Rosasco, S.L., Beard, J.K., Hallford, D.M., and Summers, A.F., 2019. Evaluation of estrous synchronization protocols on ewe reproductive efficiency and profitability. Animal Reproduction Science, 210, 106191.

    Article  CAS  PubMed  Google Scholar 

  • Salas-Razo, G., Rojo-Martínez, J.A., Garcidueñas-Piña, R., and Espinoza-Villavicencio, J.L., 2014. Effect of an intermediate dose of melengestrol acetate (MGA) on ovulation inhibition in ewes. International Journal of Bioscience, Biochemistry and Bioinformatics, 4, 171.

    Article  CAS  Google Scholar 

  • Sareminejad, P., Tabatabaei, S., Mamouei, M., Mirzadeh, K., and Boujarpour, M., 2014. The effects of short and long term medroxy progesterone acetate (MAP) sponge treatments on reproductive performance during the non-breeding season of Arabian ewes. Iranian Journal of Applied Animal Science, 4, 747-751.

    Google Scholar 

  • Sharkey, S., Callan, R.J., Mortimer, R., and Kimberling, C., 2001. Reproductive techniques in sheep. Veterinary Clinics: Food Animal Practice, 17, 435-455.

    CAS  Google Scholar 

  • Simonetti, L., Blanco, M., and Gardón, J.C., 2000. Estrus synchronization in ewes treated with sponges impregnated with different doses of medroxyprogesterone acetate. Small Ruminant Research, 38, 243-247.

    Article  CAS  PubMed  Google Scholar 

  • Souza-Fabjan, J.M.G., Balaro, M.F.A., Bragança, G.M., Pinto, P.H.N., de Almeida, J.G., Moura, A.B.B., da Fonseca, J.F., and Brandão, F.Z., 2018. Use of two doses of cloprostenol in different intervals for estrus synchronization in hair sheep under tropical conditions. Tropical animal health and production, 50, 427-432.

    Article  PubMed  Google Scholar 

  • Suárez, G., Zunino, P., Carol, H., and Ungerfeld, R., 2006. Changes in the aerobic vaginal bacterial mucous load and assessment of the susceptibility to antibiotics after treatment with intravaginal sponges in anestrous ewes. Small Ruminant Research, 63, 39-43.

    Article  Google Scholar 

  • Swartz, J.D., Lachman, M., Westveer, K., O’Neill, T., Geary, T., Kott, R.W., Berardinelli, J.G., Hatfield, P.G., Thomson, J.M., and Roberts, A., 2014. Characterization of the vaginal microbiota of ewes and cows reveals a unique microbiota with low levels of lactobacilli and near-neutral pH. Frontiers in Veterinary Science, 1, 19.

    Article  PubMed  PubMed Central  Google Scholar 

  • Swelum, A.A.-A., Alowaimer, A.N., and Abouheif, M.A., 2015. Use of fluorogestone acetate sponges or controlled internal drug release for estrus synchronization in ewes: effects of hormonal profiles and reproductive performance. Theriogenology, 84, 498-503.

    Article  CAS  PubMed  Google Scholar 

  • Swelum, A.A.-A., Saadeldin, I.M., Moumen, A.F., Ali, M., Ba-Awadh, H., and Alowaimer, A.N., 2019. Effects of long-term controlled internal drug release reuse on reproductive performance, hormone profiles, and economic profit of sheep. Revista Brasileira de Zootecnia, 48. https://doi.org/10.1590/rbz4820180085

  • Swelum, A.A.-A., Saadeldin, I.M., Moumen, A.F., Ali, M.A., and Alowaimer, A.N., 2018. Efficacy of controlled internal drug release (CIDR) treatment durations on the reproductive performance, hormone profiles, and economic profit of Awassi ewes. Small Ruminant Research, 166, 47-52.

    Article  Google Scholar 

  • Texeira, T.A., Da Fonseca, J.F., de Souza-Fabjan, J.M.G., de Rezende Carvalheira, L., de Moura Fernandes, D.A., and Brandão, F.Z., 2016. Efficiency of different hormonal treatments for estrus synchronization in tropical Santa Inês sheep. Tropical animal health and production, 48, 545-551.

    Article  PubMed  Google Scholar 

  • Timurkan, H., and Yildiz, H., 2005. Synchronization of oestrus in Hamdani ewes: the use of different PMSG doses. Bulletin-Veterinary Institute in Pulawy, 49, 311.

    Google Scholar 

  • Titi, H., Kridli, R., and Alnimer, M., 2010. Estrus synchronization in sheep and goats using combinations of GnRH, progestagen and prostaglandin F2α. Reproduction in Domestic Animals, 45, 594-599.

    CAS  PubMed  Google Scholar 

  • Ungerfeld, R., 2011. Combination of the ram effect with PGF2α estrous synchronization treatments in ewes during the breeding season. Animal Reproduction Science, 124, 65-68.

    Article  CAS  PubMed  Google Scholar 

  • Ungerfeld, R., Carbajal, B., Rubianes, E., and Forsberg, M., 2005. Endocrine and ovarian changes in response to the ram effect in medroxyprogesterone acetate-primed corriedale ewes during the breeding and nonbreeding season. Acta Veterinaria Scandinavica, 46, 33.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Ungerfeld, R., Clemente, N., Bonjour, L., and Orihuela, A., 2014. Equine chorionic gonadotrophin administration to rams improves their effectiveness to stimulate anoestrous ewes (the “ram effect”). Animal Reproduction Science, 149, 194-198.

    Article  CAS  PubMed  Google Scholar 

  • Ungerfeld, R., Ramos, M., and González-Pensado, S., 2008. Ram effect: adult rams induce a greater reproductive response in anestrous ewes than yearling rams. Animal Reproduction Science, 103, 271-277.

    Article  CAS  PubMed  Google Scholar 

  • Ungerfeld, R., and Rubianes, E., 2002. Short term primings with different progestogen intravaginal devices (MAP, FGA and CIDR) for eCG-estrous induction in anestrus ewes. Small Ruminant Research, 46, 63-66.

    Article  Google Scholar 

  • Vilariño, M., Cuadro, F., dos Santos-Neto, P., García-Pintos, C., and Menchaca, A., 2017. Time of ovulation and pregnancy outcomes obtained with the prostaglandin-based protocol Synchrovine for FTAI in sheep. Theriogenology, 90, 163-168.

    Article  PubMed  CAS  Google Scholar 

  • Vilariño, M., Rubianes, E., and Menchaca, A., 2013. Ovarian responses and pregnancy rate with previously used intravaginal progesterone releasing devices for fixed-time artificial insemination in sheep. Theriogenology, 79, 206-210.

    Article  PubMed  CAS  Google Scholar 

  • Wheaton, J.E., Carlson, K.M., Windels, H.F., and Johnston, L.J., 1993. CIDR: a new progesterone-releasing intravaginal device for induction of estrus and cycle control in sheep and goats. Animal Reproduction Science, 33, 127-141.

    Article  Google Scholar 

  • Zarkawi, M., 2001. Oestrous synchronisation and twinning rate of Syrian Awassi ewes treated with progestagen and PMSG during the breeding season. New Zealand Journal of Agricultural Research, 44, 159-163.

    Article  CAS  Google Scholar 

  • Zeleke, M., Greyling, J., Schwalbach, L., Muller, T., and Erasmus, J., 2005. Effect of progestagen and PMSG on oestrous synchronization and fertility in Dorper ewes during the transition period. Small Ruminant Research, 56, 47-53.

    Article  Google Scholar 

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  1. Department of Veterinary Clinical Sciences, University of Poonch Rawalakot, Azad Kashmir, Pakistan

    Nasir Hameed & Muhammad Zubair

  2. Department of Theriogenology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan

    Nasir Hameed & Muhammad Irfan-ur-Rehman Khan

  3. The Animal Sciences Institute, NARC, Islamabad, Pakistan

    Syed Murtaza Hassan Andrabi

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  1. Nasir Hameed
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NH, MIRK and MZ conceived the idea, NH and MIRK retrieved and analyzed data, drafted, and revised the manuscript. SMHA and all other authors critically reviewed the manuscript.

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Hameed, N., Khan, M.IuR., Zubair, M. et al. Approaches of estrous synchronization in sheep: developments during the last two decades: a review. Trop Anim Health Prod 53, 485 (2021). https://doi.org/10.1007/s11250-021-02932-8

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