Reproductive Performance After hCG or GnRH Administration of Long-Term Progestagen Treatment of Fat Tailed Ewes During Seasonal Anoestrus

Abstract

This research was carried out to evaluate the effect of hCG or GnRH two days after long-term progestagen treatment on the reproductive performance of Mehraban ewe during seasonal anoestrus under field conditions. A total of 75 ewes pretreated with intravaginal progestagen sponges left in situ for 14 days and all ewes were treated with Pregnant Mare Serum Gonadotrophin at the time of sponge removal. Two days after removal of sponge, the ewes in two groups were injected (im), either with hCG (hCG group) or with GnRH analogue (GnRH group) and the other group remained untreated and served as control. Blood samples were collected on day 19 after sponge removal from all animals to measure serum concentration of progesterone in order to pregnancy diagnosis. The reproductive performance of the Mehraban ewes in all groups was assessed by lambing data. The pregnancy rate of ewes was highest in the hCG group (86.4%), compared to the control (60%; P<0.05) and GnRH (69.2%; P>0.05) groups, respectively. The percentage of lambing rate of the ewes which lambed from mating at the induced oestrus was highest in the hCG group (85.7%), when compared to the control (58.3%; P<0.05) and GnRH (66.7%; P>0.05) groups. The highest proportion of twin lamb birth rate was recorded in the hCG group (61.1%), compared to the control (57.1%; P>0.05) and GnRH (31.3%; P<0.05) groups. The hCG group recorded significantly greater mean single and twin lamb birth weight compared to the control group (P<0.05). It can be concluded that hCG injection, two days after sponge removal, increases prolificacy and can improve reproductive performance of Mehraban ewes outside the breeding season, which is in high importance for sheep holders from economical point of view.

Key Words: Ewe, anoestrus, progestagen, hCG, GnRH, prolificacy

Keywords

• Ewe, anoestrus, progestagen, hCG, GnRH, prolificacy

ANÖSTRUS DÖNEMİNDE YAĞLI KUYRUK KOYUNLARA UZUN SÜRELİ PROGESTAGEN UYGULAMASINI TAKİBEN YAPILAN hCG VEYA GnRH ENJEKSİYONUNUN REPRODÜKTİF PERFORMANS ÜZERİNE ETKİSİ

Abstract

Bu çalışmada saha şartlarında bakılan Mehraban ırkı koyunlara anöstrus döneminde uzun süreli progesteron uygulamasının bitiminden iki gün sonra uygulanan hCG veya GnRH hormonlarının reprodüktif performans üzerine etkinliğini araştırıldı. Kullanılan 75 adet koyunun vajinasına progestagen emdirilmiş süngerler yerleştirildikten sonra 14 gün beklendi, süngerlerin çıkarıldığı günde tüm koyunlara gebe kısrak serum gonadotropin hormonu uygulandı. Sünger çıkarılmasından iki gün sonra çalışma koyunlarından ilk gruba hCG (im) enjeksiyonu yapıldı (hCG grup) ve diğer gruba GnRH analoğu enjekte edildi (GnRH grup), çalışma grupları dışında kalan koyunlar kontrol grubu olarak ayrıldı. Sünger çıkarılmasından 19 gün sonra serum progesteron konsantrasyon tayini ile gebelik kontrolü yapılması için tüm hayvanlardan kan alındı. Tüm gruplarda yer alan Mehraban koyunlarının reprodüktif performansları kuzulama oranları değerlendirilerek belirlendi. Gebelik oranında gruplar içinde en yüksek değer hCG grubunda (%86,4) tespit edilirken bunu sırasıyla kontrol (%60; P<0,05) ve GnRH (%69,2; P>0,05) grubu takip etmektedir. Östrusu uyarılan ve çiftleştirilen koyunlardan hCG grubunun (%85,7) kuzulama oranı, GnRH grubu (%66,7; P>0.05) ve kontrol grubu (%58,3; P<0,05) ile karşılaştırıldığında daha yüksek bulunmuştur. Grupların ikiz doğurma oranları karşılaştırıldığında en yüksek oran hCG grubunda (%61,1) tespit edilirken, kontrol grubunda (%57,1; P>0,05) ve GnRH grubunda (%31,3; P<0,05) daha düşük oranlar tespit edildi. Tek ve ikiz kuzuların doğum ağırlıkları karşılaştırıldığında hCG grubunda doğan yavruların doğum ağırlıkları kontrol grubundan belirgin şekilde yüksek olduğu gözlenmiştir (P<0,05). Sonuç olarak sezon dışı dönemde Mehraban ırkı koyunlara sünger çıkarılmasından 2 gün sonra uygulanan hCG enjeksiyonunun elde edilen yavru sayısını ve üreme performansını arttırıcı etkisi bulunmuştur, elde edilen bu artışlar koyun yetiştiricileri için ekonomik açıdan çok önemli bir noktadır.

Anahtar Kelimeler: Koyun, anöstrus, progestagen, hCG, GnRH, verimlilik

Keywords

• Koyun, anöstrus, progestagen, hCG, GnRH, verimlilik

References

1. Alkass, J.E., Hamra, A.H., Ibrahim, F.F., 1989. Combined effect of flushing and hormonal treatment on the reproductive performance of Awassi ewes. Indian Journal of Animal Science 59, 1249-1252.
2. Amer, H.A., Hazzaa, A.M., 2009. The effect of different reproductive efficiency of ewes during the non- breeeding season. Veterinarski Arhiv 79, 19-30.
3. Ashworth, C.J., Sales, D.I., Wilmut, I., 1989. Evidence of an association between the survival of embryo and the periovulatory plasma progesterone concentration in the ewes. Journal of Reproduction and Fertility 87, 23-32.
4. Ataman, M.B., Akoz, M., 2006. GNRH-PGF2α and PGF2α-PGF2α synchronization in akkaraman cross-bred sheep in the breeding season. Bulletin of the Veterinary Institute in Pulawy 50, 101-104.
5. Beck, N.F.G., Jones, M., Davies, B., Peters, A.R., Williams, S.P., 1996. Oestrous synchronization in ewes: the effect of combining a prostaglandin analogue with a GnRH agonist (buserelin). Animal Science 62, 85-87.
6. Boscos, C.M., Samartzi, F.C., Dellis, S., Rogge, A., Stefanakis, A., Krambovitis, E., 2002. Use of progestagen - gonadotrophin treatments in oestrous Theriogenology 58, 1261-1272. of sheep.
7. Chenault, J.R., Kratzer, D.D., Rzepkowski, R.A., Goodwin M.C., 1990. LH and FSH response of Holstein heifers to fertirelin acetate, gonadorelin and buserelin. Theriogenology 34, 81-98.
8. Dogan, I., Nur, Z., 2006. Different oestrous induction methods during the non-breeding season in Kivircik ewes. Veterinarni Medicina 51, 133-138.

9. Edey, T.N., 1979. Embryonic mortality. In: Tomes, G.L., Robinson, D.E., Lightfoot, R.J. (Eds.), Sheep Breeding, Butterworths, London, pp. 315-323.
10. Farin, C.E., Moeller, C.L., Mayan, H., Gamboni, F., Sawyer, H.R., Niswender, G.D., 1988. Effect of luteinizing hormone and human chorionic gonadotropin on cell populations in the ovine corpus luteum. Biology of Reproduction 38, 413- 421.
11. Gomez-Brunet, A., Santiago-Moreno, J., Montoro, V., Garde, J., Pons, P., Gonzalez-Bulnes, A., Lopez-Sebastian, A., 2007. Reproductive performance and progesterone secretion in oestrous-induced Manchega ewes treated with hCG at the time of AI. Small Ruminant Research 71, 117-122.
12. Husein, M.Q., Kridli, R.T., 2003. Effect of progesterone prior to GnRH-PGF2α treatment on induction of oestrus and pregnancy in anoestrous Awassi ewes. Reproduction in Domestic Animal 38, 228-232.
13. Jordan, K.M., Inskeep, E.K., Knights, M., 2009. Use of gonadotropin releasing hormone to improve reproductive responses of ewes introduced to rams during seasonal anoestrus. Animal Reproduction Science 116, 254-264.
14. Karaca, F., Ataman, M.B., Coyan, K., 2009. Synchronization of oestrus 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.
15. Khan, T.H., Hastie, P.M., Beck, N.F.G., Khalid, M., 2003. hCG treatment on day of mating improves embryo viability and fertility in ewe lambs. Animal Reproduction Science 76, 81-89.
16. Kinser, A.R., Gibson, M.F., Vincent, D.L., Scheffrahn, N.S., Kesler, D.J., 1983. Ovarian responses administered progesterone, PMSG, hCG and (or) GnRH. Theriogenology 19, 449-460.
17. Moeini, M.M., Alipour, F., Moghadam, A., 2009. The effect of human chorionic gonadotropin on the reproduction performance in Lory sheep synchronized with different doses of pregnant mare serum gonadotropin outside the breeding season. Asian Journal of Animal and Veterinary Advances 4, 9-15.
18. Nancarrow, C.D., 1994. Embryonic mortality in the ewe and the doe. In: Zavy, M.T., Geisert R.D. (Eds.), Embryonic Mortality in Domestic Species, CRC Press, Boca Raton, FL.
19. Nephew, K.P., Cardenas, H., McClure, K.E., Ott, T.L., Bazer, F.W., Pope, W.F., 1994. Effects of gonadotropin or progesterone before maternal recognition development and pregnancy in sheep. Journal of Animal Science 72, 453-458. chorionic of on blastocyst
20. Safdarian, M., Kafi, M., Hashemi, M., 2006. Reproductive performance of Karakul ewes following different oestrous synchronisation treatments outside the natural breeding season. South African Journal of Animal Science 36, 229- 234.
21. Schmitt, E.J.P., Barros, C.M., Fields, P.A., Fields, M.J., Diaz, T., Kluge, J.M., Thatcher, W.W., 1996. A cellular and endocrine characterization of the original and induced corpus luteum after administration of a gonadotropin-releasing hormone gonadotropin on day five of the oestrous cycle. Journal of Animal Science 74, 1915-1929.
22. Titi, H.H., Kridli, R.T., Alnimer, M.A., 2010. Oestrous synchronization in sheep and goats using combination of GnRH, progestagen and prostaglandin F2. Reproduction in Domestic Animal 45, 594-599.
23. Twagiramungu, H., Guilbault, L.A., Dufour, J.J., 1995. Synchronization of ovarian follicular waves with a gonadotropin-releasing increase the precision of oestrus in cattle: a Review. Journal of Animal Science 73, 3141- 3151. agonist to
24. Ungerfeld, R., Rubianes, E., 2002. Short term primings intravaginal devices (MAP, FGA and CIDR) for eCG-estrous induciton in anoestrous ewes. Small Ruminant Research 46, 63-66.
25. Wilmut, I., Sales, D.I., Ashworth, C.J., 1986. Maternal and embryonic factors associated with prenatal loss Reproduction and Fertility 76, 851-864.
26. Windsor, D.P., 1995. Factors influencing the success of transcervical insemination in merino ewes. Theriogenology 43, 1009-1018.
27. Zamiri, M.J., Hosseini, M., 1998. Effects of human gonadotropin chorionic Phenobarbital on the reproductive performance of fat-tailed Ghezel ewes. Small Ruminant Research 30, 157-161. (hCG) and
28. Zarkawi, M., Al-Merestani, M.R., Wardeh, M.F., 1999. Induction of synchronized oestrus and early pregnancey diagnosis in Syrian Awassi ewes, outside the breeding season. Small Ruminant Research 33, 99-102.