Abecia JA, Forcada F, Gonzalez-Bulnes A. Hormonal control of reproduction in small ruminants. Anim Reprod Sci. 2012 Feb;130(3-4):173-9. https://doi.org/10.1016/j.anireprosci.2012.01.011 Baril G, Leboeuf B, Saumande J. Synchronization of estrus in goats: The relationship between time of occurrence of estrus and fertility following artificial insemination. Theriogenology. 1993 Sep;40(3):621-8. https://doi.org/10.1016/0093-691X(93)90414-Z Biehl MV, de Ferraz Junior MVC, Barroso JPR, Susin I, Ferreira EM, Polizel DM, Pires AV. The reused progesterone device has the same effect on short or long estrus synchronization protocols in tropical sheep. Trop Anim Health Prod. 2019 Jul;51(6):1545-9. https://doi.org/10.1007/s11250-019-01841-1 Blaschi W, Lunardelli PA, Marinho LS, Max MC, Santos GM, Silva-Santos KC, Melo-Sterza FA, Baldassarre H, Rigo TR, Seneda MM. Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination. J Vet Sci. 2014;15(3):433-7. https://doi.org/10.4142/jvs.2014.15.3.433 Bodin L, Drion PV, Remy B, Brice G, Cognie Y, Beckers JF. Anti-PMSG antibody levels in sheep subjected annually to oestrus synchronisation. Reprod Nutr Dev. 1997 Nov-Dec;37(6):651-60. https://doi.org/10.1051/rnd:19970604 Casali R, Pinczak A, Cuadro F, Guillen-Munoz JM, Mezzalira A, Menchaca A. Semen deposition by cervical, transcervical and intrauterine route for fixed-time artificial insemination (FTAI) in the ewe. Theriogenology. 2017 Nov;103:30-5. https://doi.org/10.1016/j.theriogenology.2017.07.021 Cosentino IO, Balaro MFA, Arashiro EKN, Santos JDR, Carvalho ABDS, Clariget RP, Ungerfeld R, Brandao FZ. Hormonal protocols for early resynchronization of ovulation in ewes: The use of progestagens, eCG, and inclusion of early pregnancy diagnosis with color Doppler ultrasound. Theriogenology. 2019 Jul 15;133:113-8. https://doi.org/10.1016/j.theriogenology.2019.04.033 Das GK, Naqvi SM, Gulyani R, Pareek SR, Mittal JP. Effect of two doses of progesterone on estrus response and fertility in acycling crossbred Bharat Merino ewes in a semi-arid tropical environment. Small Rumin Res. 2000 Jul 1;37(1-2):159-63. https://doi.org/10.1016/S0921-4488(99)00151-0 Dirandeh E. Starting Ovsynch protocol on day 6 of first postpartum estrous cycle increased fertility in dairy cows by affecting ovarian response during heat stress. Anim Reprod Sci. 2014 Oct;149(3-4):135-40. https://doi.org/10.1016/j.anireprosci.2014.07.018 Dogan I, Nur Z. Different estrous induction methods during the non-breeding season in Kivircik ewes. Vet Med-Czech. 2006 Apr;51(4):133-8. https://doi.org/10.17221/5532-VETMED Dogan I, Nur Z, Kilinc B. Different estrus induction protocols and fixed time artificial insemination during the anoestrous period in non-lactating Kivircik ewes. J Hell Vet Med Soc. 2018 Mar;69(1):801-8. https://doi.org/10.12681/jhvms.16429 Gibbons AE, Fernandez J, Bruno-Galarraga MM, Spinelli MV, Cueto MI. Technical recommendations for artificial insemination in sheep. Anim Reprod. 2019 Nov 18;16(4):803-9. https://doi.org/10.21451/1984-3143-AR2018-0129 Gumen A, Keskin A, Yilmazbas-Mecitoglu G, Karakaya E, Alkan A, Okut H, Wiltbank MC. Effect of presynchronization strategy before Ovsynch on fertility at first service in lactating dairy cows. Theriogenology. 2012 Nov;78(8):1830-8. https://doi.org/10.1016/j.theriogenology.2012.07.021 Herlihy MM, Giordano JO, Souza AH, Ayres H, Ferreira RM, Keskin A, Nascimento AB, Guenther JN, Gaska JM, Kacuba SJ, Crowe MA, Butler ST, Wiltbank MC. Presynchronization with double-Ovsynch improves fertility at first postpartum artificial insemination in lactating dairy cows. J Dairy Sci. 2012 Dec;95(12):7003-14. https://doi.org/10.3168/jds.2011-5260 Kaya S, Kacar C, Kaya D, Aslan S. The effectiveness of supplemental administration of progesterone with GnRH, hCG and PGF2α on the fertility of Tuj sheep during the non-breeding season. Small Rumin Res. 2013 Jul;113(2-3):365-70. https://doi.org/10.1016/j.smallrumres.2013.03.018 Kenyon PR, Maloney SK, Blache D. Review of sheep body condition score in relation to production characteristics. New Zeal J Agric Res. 2014 Jun;57(1):38-64. https://doi.org/10.1080/00288233.2013.857698 Martinez-Ros P, Lozano M, Hernandez F, Tirado A, Rios-Abellan A, Lopez-Mendoza MC, Gonzalez-Bulnes A. Intravaginal device-type and treatment-length for ovine estrus synchronization modify vaginal mucus and microbiota and affect fertility. Animals (Basel). 2018 Nov 29;8(12):1-8. https://doi.org/10.3390/ani8120226 Masoudi R, Zare Shahneh A, Towhidi A, Kohram H, Akbarisharif A, Sharafi M. Fertility response of artificial insemination methods in sheep with fresh and frozen-thawed semen. Cryobiology. 2017 Feb;74:77-80. https://doi.org/10.1016/j.cryobiol.2016.11.012 Menchaca A, Rubianes E. New treatments associated with timed artificial insemination in small ruminants. Reprod Fertil Dev. 2004;16(4):403-13. https://doi.org/10.1071/RD04037 Miranda VO, Oliveira FC, Dias JH, Vargas Junior SF, Goularte KL, Sa Filho MF, Sa Filho OG, Baldassarre H, Vieira AD, Lucia T Jr, Gasperin BG. Estrus resynchronization in ewes with unknown pregnancy status. Theriogenology. 2018 Jan 15;106:103-7. https://doi.org/10.1016/j.theriogenology.2017.10.019 Ozyurtlu N, Ay SS, Kucukaslan I, Gungor O, Aslan S. Effect of subsequent two short-term, short-term, and long-term progestagen treatments on fertility of Awassi ewes out of the breeding season. Ankara Üniv Vet Fak Derg. 2011 Jan;58(2):105-9. https://doi.org/10.1501/Vetfak_0000002458 Richardson BN, Hill SL, Stevenson JS, Djira GD, Perry GA. Expression of estrus before fixed-time AI affects conception rates and factors that impact expression of estrus and the repeatability of expression of estrus in sequential breeding seasons. Anim Reprod Sci. 2016 Mar;166:133-40. https://doi.org/10.1016/j.anireprosci.2016.01.013 Rosasco SL, Beard JK, Hallford DM, Summers AF. Evaluation of estrous synchronization protocols on ewe reproductive efficiency and profitability. Anim Reprod Sci. 2019 Nov;210:1-6. https://doi.org/10.1016/j.anireprosci.2019.106191 Roy F, Combes B, Vaiman D, Cribiu EP, Pobel T, Deletang F, Combarnous Y, Guillou F, Maurel MC. Humoral immune response to equine chorionic gonadotropin in ewes: Association with major histocompatibility complex and interference with subsequent fertility. Biol Reprod. 1999a Jul;61(1):209-18. https://doi.org/10.1095/biolreprod61.1.209 Roy F, Maurel MC, Combes B, Vaiman D, Cribiu EP, Lantier I, Pobel T, Deletang F, Combarnous Y, Guillou F. The negative effect of repeated equine chorionic gonadotropin treatment on subsequent fertility in Alpine goats is due to a humoral immune response involving the major histocompatibility complex. Biol Reprod. 1999b Apr;60(4):805-13. https://doi.org/10.1095/biolreprod60.4.805 Scaramuzzi RJ, Campbell BK, Downing JA, Kendall NR, Khalid M, Munoz-Gutierrez M, Somchit A. A review of the effects of supplementary nutrition in the ewe on the concentrations of reproductive and metabolic hormones and the mechanisms that regulate folliculogenesis and ovulation rate. Reprod Nutr Dev. 2006 Jul-Aug;46(4):339-54. https://doi.org/10.1051/rnd:2006016 Titi HH, Kridli RT, Alnimer MA. Estrus synchronization in sheep and goats using combinations of GnRH, progestagen and prostaglandin F2alpha. Reprod Domest Anim. 2010 Aug;45(4):594-9. Tsakmakidis IA. Ram semen evaluation: Development and efficiency of modern techniques. Small Rumin Res. 2010 Aug;92(1-3):126-30. https://doi.org/10.1016/j.smallrumres.2010.04.017 Ungerfeld R, Rubianes E. Short term primings with different progestogen intravaginal devices (MAP, FGA and CIDR) for eCG-estrous induction in anestrus ewes. Small Rumin Res. 2002 Oct;46(1):63-6. https://doi.org/10.1016/S0921-4488(02)00105-0 Ustuner B, Gunay U, Nur Z, Ustuner H. Effects of long and short-term progestagen treatments combined with pmsg on oestrus synchronization and fertility in awassi ewes during the breeding season. Acta Vet Brno. 2007 Jul;76(3):391-7. https://doi.org/10.2754/avb200776030391 Vinoles C, Meikle A, Forsberg M, Rubianes E. The effect of subluteal levels of exogenous progesterone on follicular dynamics and endocrine patterns during early luteal phase of the ewe. Theriogenology. 1999 May;51(7):1351-61. https://doi.org/10.1016/S0093-691X(99)00079-5 Vinoles C, Forsberg M, Banchero G, Rubianes E. Effect of long-term and short-term progestagen treatment on follicular development and pregnancy rate in cyclic ewes. Theriogenology. 2001 Mar 1;55(4):993-1004. https://doi.org/10.1016/S0093-691X(01)00460-5 Yuthasastrakosol P, Palmer WM, Howland BE. Luteinizing hormone, oestrogen and progesterone levels in peripheral serum of anoestrous and cyclic ewes as determined by radioimmunoassay. J Reprod Fertil. 1975 Apr;43(1):57-65. https://doi.org/10.1530/jrf.0.0430057 Zeleke M, Greyling JPC, Schwalbach LMJ, Muller T, Erasmus JA. Effect of progestagen and PMSG on oestrous synchronization and fertility in Dorper ewes during the transition period. Small Rumin Res. 2005 Jan;56(1-3):47-53. https://doi.org/10.1016/j.smallrumres.2003.12.006