Hormonal Changes During Busserlin (GnRH) Priming Regimen for Superovulation in the Camel (Camelus dromedarius)

(Sayed Taha Ismail, Marzouk bin Mohammed)

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Abstract

Seven mature non-pregnant female camels (Camelus dromedarius) have been used in this study. The female camels were injected with 20 µg. buserlin at the first day of the experiment, then scanned for ovarian activities. Superovulatory treatment commenced when a minimal ovarian activity was observed. Superovulatory treatment consisted of a combination of follicle stimulating hormone (FSH) and equine chorionic gonadotrophin (eCG) . One dose of 2000IU eCG was intramuscularly injected for all female camels, but 50mg FSH was splitted and injected twice daily for 4 consecutive days in a decreasing manner. The female camels were twice mated (12 hours apart) with fertile male camels when the ovarian follicles are considered sufficiently mature at 1.3 to 1.9 cm in diameter. Each female camel received 20 µg buserlin at the time of the first mating. All experimental camels responded to the superovulation regimen. The lowest response was 7Corpora lutea, while the highest response was 20Corpora lutea. The over all average of the number of ovarian corpora lutea was 13.43±1.77. The number of anovulated follicles ranged from 0 to 2 with an average of 1.57±0.28. Plasma progesterone concentrations showed an increase from 2.21 ± 1.01 ng/ml before GnRH injection to 4.33 ± 0.96 ng/ml at the time of superovulatory treatment. A sharp increase in plasma progesterone concentration to 18.2 ± 4.78 ng/ml was measured 8 days post-mating. Plasma estradiol 17 ß concentration was nearly constant throughout the experimental period. It fluctuated around 22.00 pg/ml before GnRH treatment and 18.00 pg/ml 8 days post-mating. A highly significant negative correlations (P<0.01) was observed between the ovarian response and the plasma estradiol (r= -0.84) concentration before initiation of superovulation. There was a significant (P<0.05) correlation coefficient between ovarian response and the plasma progesterone concentrations (r= 0.73) at the day of recovery.
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