Ovarian follicular dynamics in buffalo cows (Bubalus bubalis)

Area of Science:

• Reproductive biology
• Veterinary science
• Animal reproduction

Background:

• Understanding follicular dynamics is crucial for reproductive efficiency in livestock.
• Egyptian buffalo cows exhibit unique reproductive cycles that require specific investigation.
• Previous research on buffalo follicular dynamics is limited, necessitating further study.

Purpose of the Study:

• To investigate follicular dynamics and the functional status of dominant follicles during the oestrous cycle in Egyptian buffalo cows.
• To correlate follicular development with hormonal profiles and histological changes.
• To identify patterns in follicular wave emergence and regression.

Main Methods:

• Collection and examination of 200 buffalo cow genital tracts post-slaughter.
• Categorization of oestrous cycle stages based on corpus luteum morphology.
• Evaluation of ovarian follicular populations and determination of dominant follicles (DFs).
• Histological examination of DFs and sub-dominant follicles.
• Radioimmunoassay (RIA) analysis of estradiol-17beta (E2) and progesterone (P4) in follicular fluid.

Main Results:

• Dominant follicles exhibited dynamic changes in endocrine function and viability throughout the oestrous cycle.
• Between days 5-10, DFs were predominantly E2-dominant and non-atretic.
• Between days 11-17, approximately half of DFs became P4-dominant and atretic.
• From days 18-21, all DFs were functionally active and non-atretic.
• Ovaries consistently showed at least one large follicle between days 18-21.

Conclusions:

• Follicular dynamics in Egyptian buffalo cows typically occur in two wave-like patterns.
• Dominant follicle function is cyclical, involving periods of activity and inactivity (atresia).
• These findings contribute to a better understanding of buffalo reproductive physiology and may inform breeding strategies.