الفهرس 
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Estrous Synchronization ProtocolsOnly 14 pages are availabe for public view
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Abstract
The Aim of this work is to compare two estrous synchronization protocol using Ov-synch protocol and double injection of PGF2α protocol and to study the follicular dynamic, onset of estrus, end of estrus, duration of estrus, time of ovulation, animals come in estrus, pregnancy rate and relation between the follicular growth diameter and estrogen level in both groups during autumn.
The study was conducted during the autumn breeding season (September -October) at the Animal Production Research Station in Malawi for the Animal Production Research Institute in Menia.
A total of 60 ewes Farafra strain, the ewes were divided into two equal groups (30 ewes each):
group 1 (Ov-synch program): At day 1 (D1) the ewes received an IM injection of 0.01 mg (2.5 ml) of the GnRH analog Buserelin (Receptal, 0.004 mg/ml, MSD, Germany) followed at day 8 (D8) injection of 250 μg (1 mL) of PGF2α analog cloprostenol ( Estrumate, 250 μg/ml, MSD, Germany ) and at day 10 (D10) all of the ewes received a second IM injection of 0.01 mg (2.5 ml) of the GnRH analog Buserelin (Receptal, 0.004 mg/ml, MSD, Germany).
group 2 (Double Injection of PGF2α): Ewes were synchronized with two injections of 250 μg (1 mL) of PGF2α analog cloprostenol (Estrumate, 250 μg/ml, MSD, Germany) with 10 days apart (D1-D10).
The results showed that the follicular recruitment started at (40.57 ± 3.6h) in the Ov- synchronization group from the injection of PGF2α while in the PGF2α group the recruitment was (28.6 ±2.6 h) from second injection of PGF2α. The size and number of the ovulatory follicle had no significant difference both groups.
The duration of treatment estrus in the Ov synchronization group was (20-24 h) with an average (20.4 ± 0.4 h) while in the PGF2α group, the duration of the estrus was variable (16-68 h) with an average (32 ± 2.9 h).
The results showed that the onset of estrus was significantly affected (P< 0.0001) by treatment. In the Ov synchronization group, the onset of estrus (11-13 h) was on average (12 ± 0.1 h) while in the PGF2α group, the onset of estrus was variable (28–108 h) with an average (41.3 2.8 h).
It was reported that estrus end was significantly affected (P< 0.0001) by treatment. In the OV synchronization group the estrus end (32 - 36 h) was an average (32.2 ± 0.2 h) while in the PGF2α group, the end temperature was variable (48 - 124 h) with an average (72.5 ± 3.2h).
The results revealed that ovulation time was significantly affected (P< 0.0001) by treatment. In the Ov synchronization group, ovulation time was (12 - 36 h) with mean (28 ± 2.2 hours) while in PGF2α group, ovulation time was variable (48 - 120 hours) with mean (74.5 ± 4 h).
The numbers of animals come in heat in the Ov-synchronization group was 60% while in the PGF2α group it was 100%.
The results showed that the ratio of the number of animals come in heat to the number of animals that had been pregnancy in the Ov- synchronization group was 89% while in the PGF2α group it was 73%.