Acta Vet. Brno 2025, 94: 289-296
https://doi.org/10.2754/avb202594040289
Evaluating the effect of GnRH on reproductive performance in nulliparous Assaf ewes
References
1. AT, Havelaar AH, McKune SL, Eilittä M, Dahl GE 2020: Animal source foods: sustainability problem or malnutrition and sustainability solution? Perspective matters. Global Food Secur 25: 100325
<https://doi.org/10.1016/j.gfs.2019.100325>
2. MH, Kadhim AH, AL-Thuwaini TM 2022: The reproductive traits of sheep and their influencing factors. Rev Agric Sci 10: 82-89
<https://doi.org/10.7831/ras.10.0_82>
3. A, Santos-Jimenez Z, Encinas T, Martinez-Ros P, Gonzalez-Bulnes A 2020: Use of GnRH for synchronization of the follicular wave in assisted reproductive technologies in sheep: A preliminary study. Animals 10: 1208
<https://doi.org/10.3390/ani10071208>
4. D, Birdane MK, Özenç E, Yeni D, Doğan İ 2013: Effectiveness of different progesterone analogues and GnRH on reproductive parameters in nulliparous Saanen goats at the end of the transition period. Kafkas Univ Vet Fak. Derg 19 (Suppl-A): A181-A186
5. JP, Pérez-Clariget R, Ungerfeld R 2024: Litter size affects ovulation and pregnancy rate after a hormonal treatment without influencing expression of estrus in the anestrous season in ewes. Small Rum Res 230: 107145
<https://doi.org/10.1016/j.smallrumres.2023.107145>
6. JL 2013: Should we reject animal source foods to save the planet? A review of the sustainability of global livestock production. S Afr J Anim 43: 233-246
<https://doi.org/10.4314/sajas.v43i3.1>
7. ADS, Brandão FZ, Nogueira LAG, Fonseca JFD 2012: Effects of GnRH administration on ovulation and fertility in ewes subjected to estrous synchronization. R Bras Zootec 41: 1412-1418
<https://doi.org/10.1590/S1516-35982012000600014>
8. SU, Kivrak MB, Takci A, Dinc DA, Coskun B 2022: Evaluation of hormonal protocols for induction of synchronized estrus on reproductive indices in Kangal-Akkaraman ewes during the outbreeding season. Small Rum Res 216: 106787
<https://doi.org/10.1016/j.smallrumres.2022.106787>
9. IO, Brandão FZ, Pinto PHN, Clariget RP, Ungerfeld R 2021: Fixed timed artificial insemination and early resynchronization of ovulation in different categories of ewes in grazing system: Response of multiparous, nulliparous, and lactating ewes during the breeding season. Livest Sci 247: 104461
<https://doi.org/10.1016/j.livsci.2021.104461>
10. H, Kutlu M 2022: Effect of immunomodulator usage on vaginal discharge score and conception rate in ewes synchronized with short-term progestagen and PMSG during the non-breeding season. F Ü Sağ Bil Vet Derg 36: 194-199
11. JD, Galligan DT, Thomsen N 1994: Principal descriptors of body condition score in Holstein cows. J Dairy Sci 77: 2695-2703
<https://doi.org/10.3168/jds.S0022-0302(94)77212-X>
12. B, Kisadere I 2022: The efficacy of intravaginal antibiotic or their combination with different gonadotropins on vaginitis and fertility in ewes synchronized with progesterone impregnated intravaginal sponges. Turkish J Vet Anim Sci 46: 575-581
<https://doi.org/10.55730/1300-0128.4228>
13. HMH, Kutzler MA 2021: Estrus synchronization in the sheep and goat. Vet Clin North Am Food Anim Prac 37: 125-137
<https://doi.org/10.1016/j.cvfa.2020.10.007>
14. A, Heydari Y, Asadpour R, Fathi E 2023: The effect of 2PGF2α and P4eCG protocol of estrus synchronization on reproductive performance of nulliparous Ghezel ewes. Large Animal Review 29: 135-140
15. N, Khan MIUR, Zubair M, Andrabi SMH 2021: Approaches of estrous synchronization in sheep: developments during the last two decades: a review. Trop Anim Health Prod 53: 485
<https://doi.org/10.1007/s11250-021-02932-8>
16. S, Kaçar C, Kaya D, Aslan S 2013: The effectiveness of supplemental administration of progesterone with GnRH, hCG and PGF2α on the fertility of Tuj sheep during the non-breeding season. Small Rum Res 113: 365-370
<https://doi.org/10.1016/j.smallrumres.2013.03.018>
17. M, Kuru BB, Kaçar C, Demir MC, Çetin N 2022: Effect of oestrus synchronization with different lengths of progesterone-impregnated sponges and equine chorionic gonadotropin on reproductive efficiency in Romanov ewes during the non-breeding season. Acta Vet Brno 91: 243-250
<https://doi.org/10.2754/avb202291030243>
18. P, Lozano M, Hernandez F, Tirado A, Rios-Abellan A, López-Mendoza MC, 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
<https://doi.org/10.3390/ani8120226>
19. N, Raicheva E 2014: Short term progestagen treatment for estrus synchronization at nulliparous ewes from the Synthetic Population Bulgarian Milk. Journal of International Scientific Publications: Agriculture & Food 2: 382-386
20. CA, Thompson AN, Cuevas-Reyes V, Hérnandez-Arteaga LE, Greeff JC, Ehrhardt R, Veiga-Lopez A, Martin GB 2024: Utilising male stimulus to improve the reproductive efficiency of 8-month-old nulliparous ewes and adult parous ewes. Theriogenology 217: 143-150
<https://doi.org/10.1016/j.theriogenology.2024.01.023>
21. Z, Martínez-Ros P, Encinas T, Morales-Cruz JL, Guerrero-Gallegos HZ, Gonzalez-Avalos R, Gonzalez-Bulnes A, Guillen-Muńoz JM 2022: Ovarian response and fertility after short-term progestagen/eCG treatments are compromised in nulliparous sheep during non-breeding season. Vet Sci 9: 663
22. P, Pérez C, Petrusha V, Fedorenko S, Bilyi D 2021: Induction and synchronization of oestrus in sheep and goats. J Cent Eur Agric 22: 39-53
<https://doi.org/10.5513/JCEA01/22.1.2939>
23. A, Kivrak MB, Murat H, Yüksel M 2024: Determination of reproductive response to different synchronization methods and profitability during the transition to anoestrus in multiparous Kangal sheep. Acta Vet Brno 93: 347-353
<https://doi.org/10.2754/avb202493030347>
24. HH, Kridli RT, Alnimer MA 2010: Estrus synchronization in sheep and goats using combinations of GnRH, progestagen and prostaglandin F2α. Reprod Dom Anim 45: 594-599
25. NC, Jackson DJ 2004: An update on estrus synchronization in goats: A minor species. J Anim Sci 82: E270-E276


