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Effect of Exogenous GnRH at the Time of Artificial Insemination on Reproductive Performance of Awassi Ewes Synchronized with Progestagen PMSG PGF2a Combination    
Yazarlar
Gaffari Türk
Fırat Üniversitesi, Türkiye
Seyfettin Gür
Fırat Üniversitesi, Türkiye
Mustafa Sönmez
Fırat Üniversitesi, Türkiye
Tanzer Bozkurt
Fırat Üniversitesi, Türkiye
Doç. Dr. Emrah Hicazi AKSU
Atatürk Üniversitesi, Türkiye
Hakan Aksoy
Özet
This study was carried out to investigate the efficacy of PGF 2α for oestrus synchronization (ES) in Awassi ewes to which were administered the progestagen-PMSG combination, and to evaluate the effect of the exogenous GnRH administration immediately after the artificial insemination (AI) on their pregnancy rate and lambing performance during the breeding season. The ewes (n = 33) were treated with an intravaginal sponge impregnated with 30 mg fluorogestane acetate for 12 days and were injected with 500 IU PMSG at the time of removal of the sponge. The ewes were then divided into three equal groups of 11 ewes each. One millilitre of physiological saline (0.9% NaCl; placebo) was administered to each ewe in Group 1 at the time of second AI. Approximately 4 μg GnRH (busereline) was injected to each ewe in Group 2 immediately after second AI. A total of 150 μg PGF2α (cloprostenole) was injected at the time of sponge removal on day 12 and 4 μg GnRH immediately after the second AI was also treated to each ewe in Group 3. Intracervical AI with diluted fresh semen was performed twice at 12 and 24 h following the onset of oestrus. The injection-oestrus onset and injection-oestrus-end interval in Group 3 was significantly (p < 0.001) shorter than both Groups 1 and 2. Although the pregnancy rates of Groups 2 and 3 (81.8%; 9/11) were numerically higher than of Group 1 (63.6%; 7/11), the difference among the groups was statistically insignificant. The multiple birth rate of Group 3 was found higher than Groups 1 and 2. However, the number of single lambs of Group 1 was also higher than Groups 2 and 3 (p < 0.05). Despite the litter sizes of Groups 2 (1.27; 14/11) and 3 (1.55; 17/11) being numerically higher than Group 1 (0.73; 8/11), the differences among all the groups were statistically insignificant. In conclusion, the administration of PGF2α at the time of removal of the sponge shortens the injection oestrus-onset and oestrus-end interval in Awassi ewes treated with progestagen-PMSG. Additionally, exogenous GnRH treatment immediately after the AI increases the multiple birth rate of Awassi ewes synchronized with progestagen-PMSG-PGF2α combination. © 2007 The Authors.
Anahtar Kelimeler
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı Reproduction in Domestic Animals
Dergi ISSN 0936-6768
Dergi Tarandığı Indeksler SCI
Makale Dili İngilizce
Basım Tarihi 06-2008
Cilt No 43
Sayı 3
Sayfalar 308 / 313
Doi Numarası 10.1111/j.1439-0531.2007.00896.x
Makale Linki http://doi.wiley.com/10.1111/j.1439-0531.2007.00896.x