Changes in Serum Levels of Anti-Mullerian Hormone and Ovarian
Steroids in Barki Sheep during Follicular and Early Luteal Phase of
Estrous Cycle
Reham S Waheeb
Department of Theriogenology, Faculty of
Veterinary Medicine, Alexandria University, Edfina-Behera, Egypt *Corresponding author: rwaheeb@alexu.edu.eg
Abstract
Although Anti-mullerian hormone (AMH) has been
extensively studied in ruminants in the context of assisted reproductive
techniques (ART), few data are available on its physiological levels during
estrous cycle in adult ewes. Therefore, the aim of the current study was to
investigate the daily secretion pattern of AMH, progesterone (P4), estradiol17-β
(E2) during follicular and early luteal phase in cyclic Barki ewes. After
confirmation of cyclicity using ultrasonography, a group of ewes (n=10) were
treated with GnRH-7ds-PGF2α to synchronize their ovarian activity. Blood samples
were collected and ultrasonographic scanning of ovaries was performed 2 days
before PGF2α injection, on the same day
of its injection (D 0), then continued daily until day 7 after treatment.
Changes in serum levels of AMH, P4, and E2 were determined and number of pre-ovulatory
follicles (2-5mm diameter) was recorded. Results showed that AMH levels
decreased after PGF2α injection with lowest significant concentrations (0.86±0.05
ng/ml) were recorded on day 2 (P<0.01). Whereas it increased on day 3 until day
5 then declined again thereafter. Serum AMH levels were positively correlated
(P<0.001) with number of small/medium antral follicles and P4 (r=0.88, and
r=0.41 respectively), while it was negatively correlated with E2 (r=-0.74,
P<0.001). In conclusion, the presented work showed that AMH followed a dynamic
profile during follicular and early luteal phase of adult ewes.The noticed fluctuations in AHM level could hold a clinical usefulness in
reproductive management programs of sheep, as low AMH levels were associated
with terminal follicular growth. Accordingly, an optimized estrous
synchronization protocols can be designed.