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Ovulatory response, of transferable embryos recovered from Friesian cows superovulated by two PMCG doses
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Abstract: The present study was performed to optimize a superovulation protocol of Friesian cows in order to produce a large number of good quality embryos suitable for development in culture in vitro and for transfer. Superovulation protocol was done using a single injection of two different doses of pregnant mare serum gonadotropin (PMSG) (Low, 2500 IU vs high, 3000 IU) Cows (n=30) were treated with different PMSG doses at day 10 of normal oestrus cycle, and ovarian response was evaluated by ultrasonography. Results showed that cows treated with low PMSG dose had a greater number of (P<0.01) CLs (11.67 vs. 9.33) as well as total and transferable embryos (8.3 and 5.3 vs. 7.1 and 4.2, P<0.05) than cows treated with high dose. The differences in number of unovulated follicles (NOF) and total response (number of CLs and NOF) were not affected by PMSG dose. Recovery rate of total embryos reduced (71.38 vs. 76.42%, P<0.05) and of transferable embryos increased (63 vs. 59.18%) with low compared with high dose. Low dose cows increased number of embryos at morula (2.9 vs.2.3, P<0.05) and blastocyst (1.4 VS. 0.67, P<0.01) stages compared with high dose and an opposite trend was recorded for abnormal embryos (0.60 vs. 1.1, P<0.05). The effect of dose on number of embryos at compact morula stage was not significant. Low dose increased number of excellent (4.3 vs.2.1, P<0.0l) and good (2.8 vs. 2.2, P<0.05) embryos, and decreased number of fair embryos (1.3 vs. 2.9, P<0.0l) compared with high dose. The highest survival rate of cultured embryos to develop into hatched or complete hatched blastocysts (72.7 and 63.6%) was obtained from embryos at morula stage recovered from cows superovulated by low dose compared with 68.6 and 51.4% for high dose, respectively. In the same respect, excellent embryos gave the best results, being 75 and 59.4%, respectively. For embryo transfer, pregnancy rate was 33% for fresh embryos at morula stage from Friesian cows superovulated by low dose and no pregnant for vitrified/thawed embryos recovered from superovulated Friesian cows at morula stage.
In conclusion, the obtained results, under the experimental conditions in this study, indicated that the most appropriate hormonal dose for superovulation in Friesian cows was 2500 IU PMSG to reflect the highest ovulatory response the best survival rate of in vitro culture either for stage or grade of recovered embryos and the availability of more pregnancy rate after embryo transfer.
Keywords: Friesian cows, superovulation, PMSG, embryos, survival, embryo transfer.
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| Publication year |
2009
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| Pages |
923-939
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| Availability location |
معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
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| Availability number |
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| Organization Name |
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| City |
كفر الشيخ
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| serial title |
Journal Agricultural Research Kafer El-Sheikh University
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| Author(s) from ARC |
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| External authors (outside ARC) |
عبد الخالق السيد عبد الخالق
جامعة المنصورة
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| Agris Categories |
Animal physiology - Reproduction
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AGROVOC
TERMS |
Cows.
Embryo transfer.
Superovulation.
Survival.
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| Proposed Agrovoc |
Ovulatory response;
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| Publication Type |
Journal
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