The Effect of Gonadotropin Releasing Hormone Administration on Fertility and Embryonic Loss in Goats during the Anoestrus Period

Ayşe Merve Köse, Ece Koldaş Ürer, Mustafa Kemal Sarıbay, Gökhan Doğruer, Fikret Karaka, Nurdan Çoskun Çetin, Haydar Demirezer


Background: Following the induction of oestrus out of season in small ruminants, low fertility and variations in fertility rates are associated with embryonic losses. One of the main causes of embryonic loss is luteal dysfunction. Gonadotropin Releasing Hormone (GnRH) supports the luteal structure, and increasing progesterone levels may be beneficial in terms of promoting embryonic life. The main objective of the present study was to evaluate the efficacy of GnRH administration following an oestrus induction protocol in the anoestrus season for preventing embryonic loss in goats having failure to conceive during the season. 

Materials, Methods & Results: In the study, 106 Damascus goats aged 3-5 years and weighing 45-60 kg were used. The oestrus of 106 goats in the anoestrous group was stimulated with progesterone and pregnant mare serum gonadotropin (PMSG) treatment. Out of breeding season, goats were divided into the 4 following groups: GnRH0 (n = 27), GnRH7 (n = 26), GnRH0+7 (n = 27) and control (n = 26). In each goat, an intravaginal sponge (IS) containing 20 mg of fluorogestone acetate (FGA) was placed into the vagina and left for 9 days. With the withdrawal of the sponge, 550IU PMSG and 125 μg of d-cloprostenol were injected intramuscularly. Oestrus detection was made via teaser bucks for 3 days starting 24 h after withdrawal of the IS. Eighteen bucks known to be fertile were used for breeding. Goats in the oestrus period were mated via natural breeding. The GnRH analogue lecirelin was injected intramuscularly at breeding in the GnRH0 group, on day 7 post-breeding in the GnRH7 group, and both at breeding and on day 7 post-breeding in the GnRH0+7 group. No injections were given to the control group. Blood samples for progesterone measurement were taken by jugular vena puncturing on days 3, 6, 7, 10, 13, 16, and 19 after breeding from 10 randomly chosen goats in all groups. The goats with a level of > 3.5 ng/mL of progesterone on day 21 post-breeding were evaluated as pregnant. Pregnancy was also viewed on day 50 after breeding by real-time ultrasonography (USG) with a 5-7.5 MHz convex probe. The oestrus rate was 96.23% (102/106) in the goats. The rates of onset of oestrus between 36-48 h, 48-60 h and 60 h and beyond were 38.7% (41/106), 21.7% (23/106) and 35.8% (38/106), respectively. The total pregnancy rate was 35.8% (38/106). There were no statistically significant differences (P > 0.05) found for the pregnancy rate, embryonic death rate or progesterone concentration of the groups. However, serum progesterone levels were statistically different in the GnRH7 group compared with the control group (P < 0.05).

Discussion: After synchronisation, various anti-luteolytic strategies can be used to support corpus luteum development and elevate progesterone concentration in the luteal phase to decrease embryonic loss and increase reproductive performance. Therefore, application of GnRH to support the luteal structure and to increase progesterone levels may be beneficial in terms of supporting embryonic life. The results showed that GnRH treatment on the day 7 post-breeding following oestrus induction, including FGA and PMSG, can increase serum progesterone levels in Damascus goats in the anoestrus period. However, following oestrus induction in the anoestrus period, it was seen that GnRH treatment at breeding or on day 7 after breeding did not have any positive effect on embryonic loss or reproductive performance. In conclusion, it was considered that this protocol could be implemented successfully, yielding a 35% pregnancy rate in Damascus goats in the anoestrus period, but embryonic loss must be deeply studied in detail.

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Ahmed M.M., Makawi S.E. & Jubara A.S. 1998. Synchronization of oestrus in Nubian goats. Small Ruminant Research. 30(2): 113-120.

Akar Y., Yüksel M. & Ograk Y.Z. 2014. Oestrus synchronization and reproductive performance under different protocols in anoestrus dairy goats. Research Opinions in Animal & Veterinary Sciences. 4(8): 432-436.

Alaçam E., Güven S., Ayar A. & Saban E. 1999. Effect of gonadoreline administration on blood progesterone, oestradiol 17β concentration and some fertility parameters in Angora goats. Turkish Journal of Veterinary and Animal Sciences. 23(1): 77-81.

Baki Acar D., Birdane M.K., 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 Üniversitesi Veteriner Fakültesi Dergisi. 19(A): 181-186.

Baril G., Remy B., Vallet J.C. & Beckers J.F. 1992. Effect of repeated use of progestagen‐PMSG treatment for estrus control in dairy goats out of breeding season. Reproduction in Domestic Animals. 27(3): 161-168.

Binelli M., Thatcher W.W., Mattos R. & Baruselli P.S. 2001. Antiluteolytic strategies to improve fertility in cattle. Theriogenology. 56(9): 1451-1463.

Cam M.A. & 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. Animal Reproduction Science. 80(1): 81-90.

Cam M.A., Kuran M., Yildiz S. & Selcuk E. 2002. Fetal growth and reproductive performance in ewes administered GnRH agonist on day 12 post-mating. Animal Reproduction Science. 72(1): 73-82.

Cengiz M. & Çolak A. 2017. Reproduction management in sheep and goats in anoestrus period. Turkiye Klinikleri Veterinary Sciences Obstetrics and Gynecology Special Topics. 3(2): 99-106.

Chao L.M., Takayama K., Nakanishi Y., Hamana K., Takagi M., Kubota C. & Kojima T. 2008. Luteal lifespan and fertility after estrus synchronization in goats. Journal of Veterinary Science. 9(1): 95-101.

Cinar M., Ceyhan A., Yilmaz O. & Erdem H. 2017. Effect of estrus synchronization protocols including PGF2α and GnRH on fertility parameters in hair goats during breeding season. Journal of Animal and Plant Sciences. 27: 1083-1087.

Doğan I., Nur Z., Gunay U., Soylu M.K. & Sonmez C. 2004. Comparison of fluorgestone and medroxyprogesterone intravaginal sponges for oestrus synchronization in Saanen does during the transition period. South African Journal of Animal Science. 34(1): 18-22.

Doğruer G., Karaca F., Koldaş Ürer E., Çoşkun Çetin N., Köse A.M., Ateş C.T., Özcan O. & Sarıbay M.K. 2019. Determination of efficient CIDR application periods in timed artificial insemination of Damascus goats during the breeding season. Ankara Üniversitesi Veteriner Fakültesi Dergisi. 66: 67-72.

Erdem H. & Sarıbay M.K. 2015. Pregnancy and diagnostic methods. In: Obstetrics and Gynecology in Farm Animals. 2nd edn. Malatya: Medipres, pp.507-521.

Fatet A., Pellicer-Rubio M.T. & Leboeuf B. 2011. Reproductive cycle of goats. Animal Reproduction Science. 124(3): 211-219.

Fernandez J., Bruno-Galarraga M.M., Soto A.T., de la Sota R.L., Cueto M.I., Lacau-Mengido I.M. & Gibbons A.E. 2019. Effect of GnRH or hCG administration on Day 4 post insemination on reproductive performance in Merino sheep of North Patagonia. Theriogenology. 126: 63-67.

Fleming S.A., Van Camp S.D. & Chapin H.M. 1990. Serum progesterone determination as an aid for pregnancy diagnosis in goats bred out of season. Canadian Veterinary Journal. 31(2): 104.

Fonseca J.F. & Torres C.A.A. 2005. Administration of hCG 5 days after breeding and reproductive performance in nulliparous dairy goats. Reproduction Domestic Animal. 40(6): 495-499.

Freitas V.J.F., Baril G. & Saumande J. 1996. Induction and synchronization of estrus in goats: the relative efficiency of one versus two fluorogestone acetate-impregnated vaginal sponges. Theriogenology. 46(7): 1251-1256.

González-Álvarez V.H., Meza-Herrera C.A., Leyva C., Alvarado-Espino A.S., Guillén-Muñoz J.M., Rodríguez-Martínez R. & Véliz-Deras F.G. 2016. Effectiveness of different hCG and GnRH based protocols in progesterone primed goats on estrus induction and reproductive outcomes in out-off-season goats. Journal of Animal Research. 6: 357.

Hashem N.M., El-Azrak K.M., El-Din A.N., Taha T.A. & Salem M.H. 2015. Effect of GnRH treatment on ovarian activity and reproductive performance of low-prolific Rahmani ewes. Theriogenology. 83(2): 192-198.

Kılboz E.İ. & Karaca F. 2010. Induction of estrus with Flugeston Acetate -Vaginal Sponge and Norgestomet-Ear Implant treatments in young goats in non breeding season. 21(1): 1-6.

Leboeuf B., Forgerit Y., Bernelas D., Pougnard J.L., Senty E. & Driancourt M.A. 2003. Efficacy of two types of vaginal sponges to control onset of oestrus, time of preovulatory LH peak and kidding rate in goats inseminated with variable numbers of spermatozoa. Theriogenology. 60(7): 1371-1378.

Luo J., Wang W. & Sun S. 2019. Research advances in reproduction for dairy goats. Asian-Australasian Journal of Animal Sciences. 32: 1284-1295.

Pierson J.T., Baldassarre H., Keefer C.L. & Downey B.R. 2001. Seasonal variation in preovulatory events associated with synchronization of estrus in dwarf goats. Theriogenology. 56(5): 759-769.

Prosperi C.P., Torres C.A.A., Guimarães J.D., Bruschi J.H., Leite P.A.G. & Maffili V.V. 2006. Pregnancy rate and progesterone concentration of Alpine and Saanen goats treated with hCG the third day after estrus. Arquivo Brasileiro de Medicina Veterinaria e Zootecnia. 58(2): 190-195.

Regueiro M., Clariget R.P., Ganzábal A., Aba M. & Forsberg M. 1999. Effect of medroxyprogesterone acetate and eCG treatment on the reproductive performance of dairy goats. Small Ruminant Research. 33(3): 223-230.

Ritar A.J., Robertson J.A. & Evans G. 1994. Ovulatory activity, hormonal induction of ovulation and fertility of young Cashmere and Angora female goats in a temperate environment. Reproduction, Fertility and Development. 6(6): 737-747.

Robin N., Laforest J.P., Lussier J.G. & Guilbault L.A. 1994. Induction of estrus with intramuscular injections of GnRH or PMSG in lactating goats (Capra hircus) primed with a progestagen during seasonal anestrus. Theriogenology. 42(1): 107-116.

Saleh M. 2011. Synchronization and superovulation of Boer goats with PGF2α and GnRH or hCG and parentage analysis using microsatellite markers. International PhD Program for Agricultural Sciences in Göttingen (IPAG) at the Faculty of Agricultural Sciences. Georg-August-University, Göttingen (Germany).

Sarıbay M.K., Doğruer G., Ergün Y., Karaca F. & Ateş C.T. 2008. Estrous induction in lactating hair goats outside the breeding season by flourogestone acetate containing vaginal sponges; the effect of GnRH and hCG applications on fertility. Eurasian Journal of Veterinary Science. 24(1): 21-27.

Simoes J. 2015. Recent advances on synchronization of ovulation in goats, out of season, for a more sustainable production. Asian Pacific Journal of Reproduction. 4(2): 157-165.

Uslu B.A. & Gülyüz F. 2009. The effects of GnRH injection after intravaginal sponge, CIDR-G and ear implant application in coloured Mohair goats during early anoestrus season. Kafkas Üniversitesi Veteriner Fakültesi Dergisi. 15(3): 385-390.

Zarkawi M., Al-Merestani M.R. & Wardeh M.F. 1999. Induction of synchronized oestrous in indigenous Damascus goats outside the breeding season. Small Ruminant Research. 33(2): 193-197.


Copyright (c) 2021 Ayşe Merve KÖSE, Ece KOLDAŞ ÜRER, Mustafa Kemal Sarıbay, Gökhan DOĞRUER, Fikret KARACA, Nurdan ÇOŞKUN ÇETİN, Haydar DEMİREZER

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