| Titles |
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English :
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Effect of season on the efficiency of PGF2 α in synchronizing the estrous cycle in subtropical ewes
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| Abstract |
Forty six native Egyptian Farafra ewes were treated with double injections of PGF2 α - 11 d apart in winter (n=16), late spring (n=16), and fall (n=14). Treatment started 3 months after lambing. Estrus-mating detection was carried out at 4-h intervals. Ultrasonic examinations were performed at 12 h intervals and blood samples were collected for assessment of progesterone concentration. The results showed that season significantly (P=0.002) affected the incidence of estrus expression in ewes after PGF2 α. treatment. The lowest incidence was noticed in late spring (43.8%), but no significant difference was observed between winter (81.3%) and fall (100%). Follicular characteristics did not differ significantly among seasons. However, season significantly (P=0.01) affected the percentage of ewes with corpus luteum at PGF2 α.-treatment. All ewes in winter and fall showed a functional corpus luteum on the day of second PGF2 α-treatment, compared to 50.0% in late spring. Moreover, mean diameter of the corpus luteum at treatment and its regression rate were significantly (P< 0.05) lower in late spring. In conclusion, these subtropical sheep showed seasonal variation in luteal function that influenced the efficiency of PGF2 α in synchronizing the estrous cycle. Better response was observed in winter and fall. In late spring, the lambing - treatment interval should be longer to include more cycling ewes in the program.
Keywords: Estrus synchronization, PGF2α, Season, sheep, Subtropics.
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| Publication year |
2009
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| Pages |
195-205
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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 |
Animal Production Research Institute (APRI)
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| City |
الغردقة
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| serial title |
Egyptian Society Animal Reproduction Fertility Twenty First Animal Congress.
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| Author(s) from ARC |
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| External authors (outside ARC) |
ديرار رفعت
طب بيطرى- جامعة سوهاج
احمد مصطفى على
طب بيطرى- جامعة سوهاج
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| Agris Categories |
Animal physiology - Reproduction
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AGROVOC
TERMS |
Oestrous cycle.
Seasons.
Sheep.
Subtropical zones.
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| Proposed Agrovoc |
Estrus synchronization;
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| Publication Type |
Conference/Workshop
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