1.Afri-Bouzebda, F., Lamraoui, R., Bouzebda, Z., Chacha, F. and Djellal-Eddine Gherissi, D.E. 2015. Effects of GnRH or hCG on ovarian response in PMSG-superovulated Ouled Djellal ewes (Algeria). Glob. Vet. 155: 498-505.
2.Ahmadi, E. and Mirzaei, A. 2016. High twin lambing rate of synchronized ewes using progestagen combined with the gonadotropins injection in breeding season. Revue. Med. Vet. 167: 28-32.
3.Ali, A. 2007. Effect of time of eCG administration on follicular response and reproductive performance of FGA-treated Ossimi ewes. Small. Rumin. Res. 72: 33-37.
4.Azawi, O.I. and Al-Mola, M.K.M.A. 2011. A study on the effect of GnRH administration on the ovarian response and laparoscopic intrauterine insemination of Awassi ewes treated with eCG to induce superovulation. Trop. Anim. Health. Prod. 43: 1351–1355.
5.Bobowiec, R., Kosior-Korzecka, U., Patkowski, K., Gruszecki, T. and Tusinska, E. 2012. Reproductive performance of PLS and BCP ewes exposed to hCG at the follicular phase of the estrous cycle. Med. Weter. 68: 226-230.
6.Cam, M.A. and Kuran, M. 2004. Effects of a single injection of hCG or GnRH agonist on day 12 post mating on fetal growth and reproductive performance of sheep. Anim. Reprod. Sci. 80: 81-90.
7.Catalano, R., Teruel, M., Gonzalez, C., Williams, S., Videla Dorna, I. and Callejasa, S. 2015. Reproductive performance of ewe lambs in non-breedingseason exposed to hCG at day 12 post mating. Small. Rumin. Res. 124: 63-67.
8.Cavalcanti, A, Brandao, F.Z., Nogueira, L.A.G. and Da Fonseca, J.F. 2012. Effects of GnRH administration on ovulation and fertility in ewes subjected to estrous synchronization. R. Bras. Zootec. 41: 1412-1418.
9.Coleson, M.P.T., Sanchez, N.S., Ashley, A.K., Ross, T.T. and Ashley, R.L. 2015. Human chorionic gonadotropin increases serum progesterone, number of corpora lutea and angiogenic factors in pregnant sheep. J. Reproduction. 150: 43–52.
10. De Rensis, F., Lopez-Gatius, F., Garcia-Ispierto, I. and Techakumpu, M. 2009. Clinical use of human chorionic gonadotropin in dairy cows: An update. J. Theriogenology. 73: 1001-1008.
11. Fukui, Y., Itagaki, R., Ishida, N. and Okada, M. 2001. Effect of different hCG treatments on fertility of estrus-induced and artificially inseminated ewes during the non-breeding season. J. Reprod. Dev. 47: 189-195.
12.Gonzalez-Bulnes, A., Baied D.T., Campbell, B.K., Cocero, M.J., Garcia-Garcia, R.M., Inskeep, E.K., Lopez-Sebastian, A., Mcneilly, A.S., Santiago-Moreno, J., Souza, C.J.H. and Veiga-Lopez, A. 2004. Multiple factors affecting the efficiency of multiple ovulation and embryo transfer in sheep and goats. Reprod. Fertil. Dev. 16: 421–435.
13.Habibizad, J. and Meamar, M. 2017. The effects of different eCG doses on reproductive performance of Torki-Ghashghaei ewes in autumn season. J. Rumin. Res. 5: 57-68. (In Persian).
14.Hashem, N.M., El-Azrak, K.M., Nour El-Din, A.N.M., Taha, T.A. and Salem, M.H. 2015. Effect of GnRH treatment on ovarian activity and reproductive performance of low-prolific Rahmani ewes. J. Theriogenology. 83: 192-198.
15.Husein, M.Q., and Ababneh, M.M. 2008. A new strategy for superior reproductive performance of ewes bred out-of-season utilizing progestagen supplement prior to withdrawal of intravaginal . J. Theriogenology. 69: 376-383.
16.Ince, D. and Karaca, O. 2009. Effects of oestrus synchronization and various doses of PMSG administrations in Chios x Kivircik (F1) sheep on reproductive performances. J. Anim. Vet. Adv. 8: 1948-1952.
17.Khan, T.H., Beck, N.F.G. and Khalid, M. 2007. The effects of GnRH analogue (buserelin) or hCG (Chorulon) on day 12 of pregnancy on ovarian function, plasma hormone concentrations, conceptus growth and placentation in ewes and ewe lambs. Anim. Reprod. Sci. 102: 247-257.
18.Lamraoui, R., Afri-Bouzebda, F., Bouzebda, Z., Franck, M. and Gherissi, D.E. 2014. Effect of repeated administration of hCG on ovarian response in PMSG-superovulated Ouled Djellal ewes (Algeria). Tropicultura. 32: 10-15.
19.Mehri, R., Rostami, B., Masoumi, R. and Shahir, M.H. 2018. Effect of injection of GnRH and hCG on day 5 post mating on maternal P4 concentration and reproductive performance in Afshari ewes. J. Comp. Pathobiol. 14: 2363-2370. (In Persian)
20.Mirzaei, A., Rezaei, M. and Asadi, J. 2014. Reproductive performance after hCG or GnRH administration of long-term progestagen treatment of fat tailed ewes during seasonal anoestrus. J. Fac. Vet. Med.
Istanbul Univ. 40: 176-182.
21.Nephew, K.P., Cardenas, H., McClure, K.E., Ott, T.L., Bazer, F.W. and Pope, W.F., 1994. Effects of administration of human chorionic gonadotropin or progesterone before maternal recognition of pregnancy on blastocyst development and pregnancy in sheep. J. Anim. Sci. 72: 453-458.
22.Occhio, M.J.D., Jillella, D. and Lindsey, B.R. 1999. Factors that influence follicle recruitment, growth and ovulation during ovarian super stimulation in heifers; opportunities to increase ovulation rate and embryo recovery by delaying the exposure of follicles to LH. Theriogenology. 51: 9-35.
23.Pappa-Michailidou, V., Avdi, M., Zafrakas, A., Alifakiotis, T. and Michailidis, J. 1997. Ovarian response to hCG injections during the prepubertal period in three breeds of sheep with different ovulation rates and litter sizes. J. Theriogenology. 47: 1215-1219.
24.Pendleton, R.J., Youngs, C.R., Rorie, R.W., Pool, S.H., Memon, M.A. and Godke, R.A. 1992. Follicle stimulating hormone versus pregnant mare serum gonadotropin for superovulation of dairy goats. Small. Rumin. Res. 8: 217-224.
25.Quintero, J., Olguin, H., Quezada, A., Janacua, H., Rivas, R. and Macias, U. 2015. Effect of hCG application on day 12 post-mating on the reproductive efficiency and plasmatic concentrations of progesterone in hair ewes. Cuban J. Agric. Sci. 49: 487-490.
26. Quintero-Elisea, J.A., Maclas-Cruz, U., Alvarez-Valenzuela, F.D., Correa-Calderon, A., Gonzalez-Reyna, A., Lucero-Magana, F.A., Soto-Navarro, S.A. and Avendano-Reyes, L. 2011. The effects of time and dose of pregnant mare serum gonadotropin (PMSG) on reproductive efficiency in hair sheep ewes. Trop. Anim. Health Prod. 43: 1567-1573.
27.Rahman, M.R., Rahman, M.M. Wan Khadijah, W.E. and Abdullah, R.B. 2017. Effect of supplementation of hCG or GnRH on ovulation and subsequent embryo production of eCG superovulated goats. Indian J. Anim. Res. 51: 438-443.
28.Sadeghi-Panah, A., Masoudi, R., Naeejian, H.R. and Akbari-Sharif, A. 2015. Effect of eCG, PGF2α and GnRH hormones on ewes' reproductive performance in breeding season. Iranian J. Anim. Sci. 46: 189-194. (In Persian)
29.SAS Institute Inc. 2003. Statistical Analysis System (SAS) User’s Guide (Version 9.1), SAS Institute, Cary, NC, USA.
30.Schmitt, E.J.P., Barros, C.M., Fields, P.A., Fields, M.J., Diaz, T., Kluge, J.M. and Thatcher, W.W. 1996. A cellular and endocrine characterization of the original and induced corpus luteum after administration of a gonadotropin-releasing hormone agonist or human chorionic gonadotropin on day five of the estrous cycle. J. Anim. Sci. 74: 1915-1929.
31.Schneider, F., Tomek, W. and Grundker, C. 2006. Gonadotropin-releasing hormone (GnRH) and its natural analogues: A review. J. Theriogenology. 66: 691-709.
32.Silva, B.D.M., Silva, T.A.S.N., Moreira, N.H., Teixeira, H.C.A., Paiva Neto, M.A., Neves, J.P. and Ramos, A.F. 2015. Ovulation induction in ewes using GnRH in long and short-term synchronization protocols. Anim. Reprod. Belo Horizonte. 12: 312-315.
33.Twagiramungu, H., Guilbault, L.A. and Dufour, J.J. 1995. Synchronization of ovarian follicular waves with a gonadotropin-releasing hormone agonist to increase the precision of oestrus in cattle: a Review. J. Anim. Sci. 73: 3141-3151.