Studies On Follicular Development Dynamics And Endocrine Mechanisms In Swamp Buffaloes In Guangxi

The studies were conducted to investigate the follicular dynamics development by B-mode ultrasonography and changes of serum concentrations of such four reproductive hormones as follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E₂) and progesterone (P₄) being assayed by RIA during the synchronized estrous cycle in swamp buffaloes in Guangxi. Results indicated as follows: (1)2 or 3 follicular waves were discovered in one estrous cycle in swamp buffaloes in Guangxi and the former was dominant (77.8%, 7/9). (2) follicular wave 1 and 2 emerged on Day 1.3, 9.8 (estrus=Day 0) in heifers while on Day 1.0, 12.3 in pluriparous buffaloes for two follicular wave model. Wave 1, 2 and the ovulatory wave emerged on Day 1.5, 8.0 and 15.5 for 3 wave model, respectively.(3) There were no significant differences (P>0.05) in the largest dominant follicle diameters between 2 and 3 follicular wave cycles. But in 2 follicular wave cycles, the largest diameter of the ovulatory dominant follicles were larger than that of the anovulatory follicles (1.14 vs 1.11, or 1.28 vs 1.00cm). The diameters of the ovulatory follicle in pluriparous buffaloes were larger than that in heifer buffaloes (1.28 vs 1.14 or 1.28 vs 1.00cm).(4) In heifer buffaloes the FSH and LH surges were emerged at 53.7±15.9h and 49.7±15.4h after estrus respectively; while they were 25.7±12.4h, 17.7±6.3h in pluriparous buffaloes, respectively.(5) 3 FSH surges appeared on Day 0, 7 and 15 in heifer buffaloes respectively. While 3 LH surges emerged on Days 0, 8 and 20 and...