Reproductive performance of Zel ewes with different dosage of eCG outside the natural breeding season

Document Type : Full Research Paper

Authors

1 Department of Clinical Sciences, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran.

2 Department of Animal Sciences, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran.

3 Department of Basic Science, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

Abstract

Estrous synchronization is a valuable management tool that has been employed successfully in enhancing reproductive efficiency, particularly in cows, ewes and does (Kusina et al., 2000). Oestrous synchronization in small ruminants is achieved either by reducing the length of the luteal phase of the oestrous cycle with prostaglandin F2α or by artificially extending it with exogenous progesterone or potent progestagens A completely randomized design experiment was carried out using eighty Zel ewes during out of season breeding to compare different dosage of equine chorionic gonadotrophin (eCG) with controlled internal drug release (CIDR) dispensers to synchronize estrous. Intravaginal progestagen was administered for a 13-day period. Upon progestagen withdrawal, doses received 350, 400, 450 and 500 IU (eCG) intramuscularly. Teaser rams (1/8 ewes) were introduced 1 d after treatment removal to detect estrus. Ewes were subjected to fertile rams 40 h after CIDR removal. The results of this experiment showed that eCG was effective when used with CIDR. Different dosage of eCG treatments had not significant effect on estrus response (100% in all groups). Enhancing the level of eCG administration led to a increase in fecundity rate and lambing rate in this study. In conclusion the CIDR device with 450 and 500 IU can improve reproductive performance in Zel ewes comparable to 350 and 400 IU eCG.

Keywords


1- Boscos, C. M., Samartzi, F. C., Dellis, S., Rogge, A., Stefanakis, A., & Krambovitis, E. (2002). Use of progestagen gonadotrophin treatments in estrus synchrsonization of sheep. Theriogenology, 58(7), 1261-1272.
2 - Dogan, I., & Nur, Z. (2006). Different estrous induction methods during the non-breeding season in Kivircik ewes. VETERINARNI MEDICINA-PRAHA-, 51(4), 133.
3 - Godfrey, R. W., Gray, M. L., & Collins, J. R. (1997). A comparison of two methods of oestrous synchronisation of hair sheep in the tropics. Animal Reproduction Science, 47(1), 99-106.
4 - Greyling, J. P. C., Kotze, W. F., Taylor, G. J., Hagendijk, W. J., & Cloete, F. (1994). Synchronization of oestrous in sheep: Use of different doses of prostagen outside the normal breeding season. South African Journal of Animal Science, 24.
5 - Hamra, A. H., McNally, J. W., Marcek, J. M., Carlson, K. M., & Wheaton, J. E. (1989). Comparison of progesterone sponges, cronolone sponges and controlled internal drug release dispensers on fertility in anestrous ewes. Animal Reproduction Science, 18(1), 219-226.
6 - Hashemi, M., Safdarian, M., & Kafi, M. (2006). Estrous response to synchronization of estrus using different progesterone treatments outside the natural breeding season in ewes. Small Ruminant Research, 65(3), 279-283.
7 - Kor, N. M., Ziaei, N., & Pour, E. E. (2012). Comparison of Reproductive Performance in Raieni Goats Following Different Estrous Synchronization Methods and Subsequent ECG Treatment During the Natural Breeding Season.
8 - Kusina, N. T., Tarwirei, F., Hamudikuwanda, H., Agumba, G., & Mukwena, J. (2000). A comparison of the effects of progesterone sponges and ear implants, PGF2alpha, and their combination on efficacy of estrus synchronization and fertility of Mashona goat does. Theriogenology, 53(8), 1567-1580.
9 - 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 gonadotrophin outside the breeding season. Asian Journal of Animal and Veterinary Advances, 4(1), 9-15.
10 - Mohajer, M., Alimon, A. R., Yaakub, H. B., Niasari-Naslaji, A., & Toghdory, A. Effects of Energy Level and PMSG Dose on Blood Progesterone, Insulin and FSH Concentration in Zel Ewes Prior to and after Mating. Journal of Animal and Veterinary Advances, 9(11), 1621-1624.
11- Rosado, J., Silva, E., & Galina, M. A. (1998). Reproductive management of hair sheep with progesterone and gonadotropins in the tropics. Small Ruminant Research, 27(3), 237-242.
12 - Safdarian, M., Kafi, M., & Hashemi, M. (2007). Reproductive performance of Karakul ewes following different oestrous synchronisation treatments outside the natural breeding season. South African Journal of Animal Science, 36(4), 229-234.
13 - Shahneh, A. Z., Tajangookeh, H. D., Panah, H. S., & Saki, A. A. (2006). Effect of controlled internal drug release device treatment duration and eCG dose on reproductive performance of seasonally anestrous fat-tailed Iranian ewes. Pakistan Journal of Biological Sciences, 9(8), 1552-1555.
14 - Simonetti, L., Ramos, G., & Gardan, J. C. (1999). Estrus presentation and distribution in ewes treated with intravaginal sponges impregnated with medroxyprogesterone acetate (MAP) in combination with pregnant mare serum gonadotropin (PMSG). Brazilian Journal of Veterinary Research and Animal Science, 36(5), 00-00.
15 - Timurkan, H. N., & Yildiz, H. T. (2005). Synchronization of oestrus in Hamdani ewes: The use of different PMSG doses. BULLETIN-VETERINARY INSTITUTE IN PULAWY, 49(3), 311.
16 - Wheaton, J. E., Carlson, K. M., Windels, H. F., & Johnston, L. J. (1993). CIDR: A new progesterone-releasing intravaginal device for induction of estrus and cycle control in sheep and goats. Animal Reproduction Science, 33(1), 127-141.
17 - Zeleke, M., Greyling, J. P. C., Schwalbach, L. M. J., Muller, T., & Erasmus, J. A. (2005). Effect of progestagen and PMSG on oestrous synchronization and fertility in Dorper ewes during the transition period. Small Ruminant Research, 56(1), 47-53.
18 - Zonturlu, A. K., Aral, F., Ozyurtlu, N., & Yavuzer, U. (2008). Synchronization of estrus using FGA and CIDR intravaginal pessaries during the transition period in awassi ewes. J. Anim. Vet. Adv, 7, 1093-1096.